System for transporting sampled signals over imperfect electromagnetic pathways

Abstract

Infrastructure electronics equipment incorporates infrastructure Local-Site Transports (LSTs). LSTs convey payload sampled signals over imperfect electromagnetic (EM) pathways whose physical properties are usually unknown when the equipment (e.g., Cameras, Displays, Set-Top Boxes) is manufactured. Prior LSTs hedge against EM pathway degradation in several ways: requiring high-quality cables (e.g., HDMI); restricting transmission distance, (e.g., HDMI); and/or reducing quality, via compression, to extend transmission distance somewhat (e.g., Ethernet). The subject of this disclosure is an infrastructure LST for sampled signals that causes the physical errors inevitably arising from propagation of sensory payloads over imperfect EM pathways to manifest in a perceptually benign manner, leveraging legacy infrastructure and reducing costs to achieve a favorable ratio of fidelity to transmission distance.

Claims

1. A method of transmitting an input payload of one or more sampled video signals over an electromagnetic pathway, said method comprising: collecting an indexed input vector of N samples from said one or more sampled video signals using a predetermined permutation; encoding said N samples of said indexed input vector with reference to a predetermined code set of N mutually-orthogonal codes each of length L into an ordered series of L output values, each of said N codes being associated with one of said samples, wherein L>=N>=2; and making available said encoded ordered series of L output values to said electromagnetic pathway as an ordered series of L analog output values.

2. The method as recited in claim 1 wherein said sampled video signals include analog samples, and wherein said encoded ordered series of L output values are analog output values.

3. The method as recited in claim 1 wherein said sampled video signals include digital samples, said method further comprising: converting said encoded ordered series of L output values into said ordered series of L analog output values.

4. The method as recited in claim 1 wherein said one or more sampled video signals originate at a single video equipment source and wherein said electromagnetic pathway terminates at a single video equipment sink.

5. The method as recited in claim 1 further comprising: continuously repeating said steps of collecting, encoding and making available for successive N samples from said one or more sampled video signals.

6. The method as recited in claim 1 further comprising: synchronously encoding said N samples into said ordered series of L output values, wherein said N samples are represented by said L output values.

7. The method as recited in claim 1 further comprising: transmitting said ordered series of L analog output values over said electromagnetic pathway to a single video equipment sink.

8. The method as recited in claim 1 wherein each of said N codes is indexed, said method further comprising: encoding said N samples by repeating, for each of L indices in the codes, the sub-steps of a) modulating each sample in the indexed input vector by the value at said each L index in said code associated with said one of said N samples, and b) summing the results of all modulations of step a) to form one of said ordered series of L output values.

9. A method of receiving an ordered series a L analog input values from an electromagnetic pathway, said method comprising: receiving said ordered series of L analog input values from said electromagnetic pathway at a receiver; decoding said L analog input values with reference to a predetermined code set of N mutually-orthogonal codes each of length L into an output vector of N samples, each of said N codes being associated with one of said samples, wherein said predetermined code set is the same as a code set used to encode said ordered series of L input values, and wherein L>=N>=2; and distributing said N samples from said output vector to one or more reconstructed sampled video signals using a predetermined permutation which is the inverse of a permutation used in a transmitter corresponding to said receiver.

10. The method as recited in claim 9 wherein said L input values for decoding are analog input values, said method further comprising: decoding said L analog input values to produce said output vector of N samples, said N samples being analog values.

11. The method as recited in claim 9 said method further comprising: converting said L analog input values into L digital input values; and decoding said L digital input values to produce said output vector of N samples, said N samples being digital values.

12. The method as recited in claim 9 wherein one or more sampled video signals corresponding to said one or more reconstructed sampled video signals originate at a single video equipment source and wherein said one or more reconstructed sampled video signals are delivered to a single video equipment sink.

13. The method as recited in claim 9 further comprising: continuously repeating said steps of receiving, decoding and distributing for successive ordered series of L analog input values.

14. The method as recited in claim 9 further comprising: synchronously decoding said L input values into said output vector of N samples, wherein said N samples represent said L input values.

15. The method as recited in claim 9 wherein said receiver is located at a single video equipment sink.

16. The method as recited in claim 9 wherein each of said N codes is indexed, said method further comprising: decoding said L input values by repeating, for each of L indices, the sub-step of repeating, for each of N indices in said output vector the sub-steps of a) correlating the value indexed by the L index in the L input values by a commonly indexed value in the code associated with the output vector index, b) summing the correlation result from sub-step a) with contents of the correspondingly indexed output vector location, to produce a summing result, and c) storing the summing result from sub-step b) in the output vector at the corresponding index.

17. An apparatus for transmitting an input payload of one or more sampled video signals over an electromagnetic pathway, said apparatus comprising: a permuter that assigns samples from said input payload to locations in an indexed input vector of N locations using a pre-determined permutation, each location in said indexed input vector receiving one of said samples; an encoder that encodes said N samples of said indexed input vector with reference to a predetermined code set of N mutually-orthogonal codes each of length L into an ordered series of L output values, each of said N codes being associated with one of said samples, wherein L>=N>=2; and an output terminal that makes available said encoded ordered series of L output values to said electromagnetic pathway as an ordered series of L analog output values.

18. The apparatus as recited in claim 17 wherein said sampled video signals include analog samples, and wherein said encoded ordered series of L output values are analog output values.

19. The apparatus as recited in claim 17 wherein said sampled video signals include digital samples, said apparatus further comprising: a digital-to-analog converter that converts said encoded ordered series of L output values into said ordered series of L analog output values.

20. The apparatus as recited in claim 17 wherein said one or more sampled video signals originate at a single video equipment source and wherein said electromagnetic pathway terminates at a single video equipment sink.

21. The apparatus as recited in claim 17 wherein said permuter continuously assigns samples from said input payload to locations in said indexed input vector, wherein said encoder continuously encodes N samples of said input vector using said code set, and wherein said output terminal continuously makes available said encoded ordered series of L output values to said electromagnetic pathway as an ordered series of L analog output values.

22. The apparatus as recited in claim 17 wherein said encoder synchronously encodes said N samples into said ordered series of L output values, wherein said N samples are represented by said L output values.

23. The apparatus as recited in claim 17 wherein said output terminal transmits said ordered series of L analog output values over said electromagnetic pathway to a single video equipment sink.

24. The apparatus as recited in claim 17 wherein each of said N codes is indexed, said apparatus further comprising: N two-input modulators, each two-input modulator corresponding to each location of said input vector, for each of the L indices in the codes, each modulator being arranged to modulate its corresponding sample in the input vector by the value at said each L index in said code associated with said one of said corresponding samples; and an N-input summer for summing the outputs of said modulators, said summer summing the results of said modulations for each of the L indices in the codes to form one of said ordered series of L output values.

25. An apparatus for receiving an ordered series of L analog input values from an electromagnetic pathway, said apparatus comprising: a receiver terminal for receiving said ordered series of L analog input values from said electromagnetic pathway at a receiver; a decoder that decodes said L analog input values with reference to a predetermined code set of N mutually-orthogonal codes each of length L into an output vector of N samples, each of said N codes being associated with one of said samples, wherein said predetermined code set is the same as a code set used to encode said ordered series of L input values, and wherein L>=N>=2; and a permuter that distributes said N samples from said output vector to one or more reconstructed sampled video signals using a predetermined permutation which is the inverse of a permutation used in a transmitter corresponding to said receiver.

26. The apparatus as recited in claim 25 wherein said L input values for decoding are analog input values, and wherein said decoder decodes said L analog input values to produce said output vector of N samples, said N samples being analog values.

27. The apparatus as recited in claim 25 said apparatus further comprising: an analog-to-digital converter that converts said L analog input values into L digital input values, wherein said decoder decodes said L digital input values to produce said output vector of N samples, said N samples being digital values.

28. The apparatus as recited in claim 25 wherein one or more sampled video signals corresponding to said one or more reconstructed sampled video signals originate at a single video equipment source and wherein said one or more reconstructed sampled video signals are delivered to a single video equipment sink.

29. The apparatus as recited in claim 25 wherein said receiver terminal continuously receives an ordered series of L analog input values, wherein said decoder continuously decodes input values using said predetermined code set, and wherein said permuter continuously distributes N samples from said output vector to one or more reconstructed sampled video signals.

30. The apparatus as recited in claim 25 wherein said decoder synchronously decodes said L input values into said output vector of N samples, wherein said N samples represent said L input values.

31. The apparatus as recited in claim 25 wherein said receiver is located at a single video equipment sink.

32. The apparatus as recited in claim 25 wherein each of said N codes is indexed, said apparatus further comprising: a set of N two-input correlators, each correlator associated with one of N locations of said output vector, each correlator having as one input a value in the ordered series of L input values and as the other input a corresponding value in the code associated with said one of N locations; and a set of N two-input summing circuits, each summing circuit associated with said one of N locations, each two-input summing circuit having as one input the output of the corresponding two-input correlator and as the other input contents of the corresponding output vector location.

Description

BRIEF DESCRIPTIONS OF FIGURES

(1) FIG. 1 depicts a method for collecting an input vector from a set of payload snippets, encoding the vector as an ordered series of output values, and making available the output values for transmission over an imperfect EM pathway;

(2) FIG. 2 depicts a method for decoding receiving an ordered series of input values from an imperfect EM pathway, decoding the input series to form an output vector, and distributing the output vector to reconstructed payload snippets;

(3) FIG. 3 illustrates a local-site transport for snippets from one or more payload signals;

(4) FIG. 4 describes one particular permutation, the permutation being a mapping from input payload snippet indices to encoder input vector indices, the example shown being round-robin assignment;

(5) FIG. 5 illustrates an example round-robin permutation from indices in snippets of a parallel-RGB input video signal to indices in an 8-element encoder input vector, for the first transport interval for a given payload;

(6) FIG. 6 further illustrates the example round-robin permutation from indices in snippets of a parallel-RGB input video signal to indices in an 8-element encoder input vector, for the second transport interval for the given payload;

(7) FIG. 7 shows an apparatus for encoding an N-sample input vector as an L-time-interval series of output values that are transmitted;

(8) FIG. 8 depicts an example of a commutating modulator;

(9) FIG. 9 illustrates an apparatus for decoding an N-sample output vector from an L-time-interval series of input values that are received;

(10) FIG. 10 shows the architecture of one synchronization acquisition and tracking circuit;

(11) FIG. 11 shows the architecture of an alternative synchronization acquisition and tracking circuit;

(12) FIG. 12 describes one particular round-robin assignment of decoder output vector indices to snippets of reconstructed payload signals;

(13) FIG. 13 illustrates an example round-robin permutation from indices in an 8-element decoder output vector to indices in snippets of a reconstructed parallel-RGB output video signal, for the first transport interval for a given payload;

(14) FIG. 14 further illustrates the example round-robin permutation from indices in an 8-element decoder output vector to indices in snippets of a reconstructed parallel-RGB output video signal, for the second transport interval;

(15) FIG. 15 shows the schema of one binary Code Book that is a subset of the identity matrix;

(16) FIG. 16 shows an example of a 127×127 binary code book whose codes is each a unique rotation of a common PN sequence;

(17) FIG. 17 shows an example of a 128×128 binary code book, which is a Walsh-Hadamard matrix;

(18) FIG. 18 shows an example of a 128×128 binary code book, which is constructed by element-wise multiplying each row of a Walsh-Hadamard matrix with a common near-PN sequence;

(19) FIG. 19 depicts the interconnections amongst the constituents of a signal collection, processing, and presentation system; and

(20) FIG. 20 shows an example oscilloscope trace of a signal arriving from the EM pathway at the decoder assembly input terminal.

GLOSSARY

(21) Terms relating to the widely understood Spread Spectrum transmission system are defined and elaborated upon in “Spread Spectrum Systems with Commercial Applications” by Robert C. Dixon, volume 3, Wiley & Sons 1994.

(22) TABLE-US-00001 Signal A fluctuating quantity conveying information Sensory Signal A signal capable of being interpreted by the human neural system (for example, light for the eyes, sound for the ears, pressure for the touch, chemicals for the taste, etc.) Perception The brain's awareness, comprehension, or understanding of a received sensory signal Color Space An abstract mathematical model, which describes a color gamut as tuples of numbers, typically as 3 or 4 components (examples include RGB, YUV, YCbCr, and CMYK) Color Value A signal amplitude corresponding to a basis vector in a color space Pixel A mathematical object associated with a geometric location in a 2D plane; a pixel is completely described as a set of Color Values, equivalently, a vector in a color space Image A 2-dimensional array of Color Values Video A sequence of Images in a predetermined electronic format which, when presented to a human viewer with sufficient rapidity, induces perception of motion and continuity “analog” Representation of a Signal A physical quantity. Physical quantities change continuously over time, and the number of different amplitudes available is limited by our ability to measure energy. Examples of analog representations of a signal include: Image sensor: Capacitance (at each “pixel” in the sensor: conditionally discharge a capacitor through a photodiode for a predetermined exposure interval; the brighter that portion of the focal area, the less charge remains in the capacitor after the exposure interval) LED/LCD display: current (the brightness of each “pixel” in the display (the smallest controllable portion) is determined by a control current any given moment) “digital” Representation of a Signal A number that changes at predetermined intervals. Examples of digital representations of a signal include: PC: An R or G or B entry in a TIF file Serial digital Interface: An ordered series of bits in a predetermined format N Number of elements in an encoder input vector and the corresponding decoder output vector . . . >1 L The common number of Chips in each code, equivalently, the number of Chip intervals applied during each encoding interval or decoding interval. L can be any counting number. The bigger L is than N, the more electrical resilience is afforded to the conveyed payload Payload The set of sampled signals that is the subject of transport Snippet A finite, ordered series of successive samples from a signal (Input or Output) Vector A finite, ordered series of samples collected from, or distributed to, payload snippets. The vector comprises N values. Imperfect Medium A physical electromagnetic (EM) propagation pathway and its environment, which combine to cause received values not to equal transmitted values, thus creating errors EM Pathway Imperfect medium. The subject of this disclosure probably works best with waveguides, because it relies on using all bandwidth and dynamic range available in the EM pathway Waveguide An EM pathway that physically constrains and confines the EM propagation vectors Code A pre-determined sequence of Chips that is L Chips long. Chip A value from a predetermined set of possible values. Chip Interval The period of time allocated for the application of one Chip in the encoder or decoder. Encoder Chip interval = encoding interval/L, and decoder Chip interval = decoding interval/L Transport interval The period of time allocated for simultaneously transmitting and receiving EM propagation across the EM pathway Binary Code a Code wherein the Chips are binary values Binary Chip The possible values are −1 or +1. (One might expect 0 or +1. Binary Chip values are −1 and +1 so as to facilitate balanced direct sequence modulation.) PN Sequence A (Binary?) Code whose output exhibits spectral characteristics similar to those of white noise. “PN” stands for “Pseudo Noise.” An ideal PN Sequence's signal energy is uniform across the transmission spectrum; such that its Fourier Transform looks like a fine-tooth comb, with equal energy at every frequency. (NB: Not all Codes are PN Sequences) Spreading A property of individual Codes, and the effect of modulating a signal by a PN Sequence: A signal modulated by an ideal PN Sequence exhibits spectral characteristics similar to those of white noise Spreading Code PN Sequence (NB: Not all PN Sequences “spread” ideally) Spreading Ratio =L =The number of successive Chips modulating each input sample =The number of successive Chips demodulating the ordered series of received values to decode the output vector =Spreading Factor (Dixon uses the terms “Spreading Ratio” and “Spreading Factor” interchangeably) =SSDS process gain =Code length =Chip sequence length =The number of encoder Chips modulating each sample in the input vector =The number of decoder Chip correlations contributing to each sample in the output vector Orthogonality A property of sets of Codes (“Code Books”). A Code Book is considered orthogonal if all of its N codes are pair-wise uncorrelated and independent sequences. (An orthogonal Code Book minimize inter-track interference among N tracks.) Walsh-Hadamard Code Set A set of PN Sequences wherein each Code constitutes an orthonormal basis vector for the L-dimensional space of Codes. For any two Codes in the set, the cross product is 0, representing nil cross-correlation. For any Code in the set, the self-product is 1, representing 100% auto-correlation.

DETAILED DESCRIPTION OF EMBODIMENTS

(23) The embodiments provided disclose ways in which certain methods and apparatus are used and useable in a range of environments.

(24) An embodiment of an encoding method and apparatus is depicted in FIG. 1 wherein the method repeats, for each Chip interval τ and, equivalently, for each common index in the Codes of a predetermined code book of indexed Chips, the steps of the method comprise but are not limited to the steps of: i) Modulating 308 each input sample 300 by the commonly indexed Chip 104 in the Code 304 corresponding to the index in the input vector 350. If the payload signals are pulsatile, then the samples are continuous values and an embodiment of modulation is an analog multiplication. If the Codes are binary (1/−1), then an embodiment of analog modulation is a conditional inversion. If the payload signals are digital, then the samples are numbers and an embodiment of modulation is a digital multiplier. If the Codes are binary (1/−1), then an embodiment of the digital multiplier is a conditional negation; ii) Summing 310 the modulation results 114 from step i) to form one of the ordered series 110 of output values 112 for transmission. If the payload signals are pulsatile, then the modulation results are continuous values and the summing is a summing circuit. If the payload signals are digital, then the modulation results are numbers, and the summing is an adder; iii) Making available the output 108 produced by step ii), at a rate sufficient to enumerate all of the code 304 indices within the Encoding Interval 12. The making available is achieved in many ways, one example is to provide the output on a port, another alternative is to store the output into a memory upon which a reading can be executed to make the output available.

(25) By following the steps disclosed to produce one value for each code 304 index during each chip interval τ during the encoding interval 12, the ordered series 110 of values 112 resulting from step iii) represents the input vector 350. This process is achieved for each encoding interval, such that the method described can be repeated for successive input vectors.

(26) In a preferred embodiment of the method of FIG. 1, the code book 354 is a set of N mutually orthogonal L-Chip 104 Codes 304, each of which is a Spreading Code. The L indices of the Codes correspond to the L chip intervals τ allocated during the encoding interval. The ratio L/N is the “SSDS Process Gain” as defined by Dixon on p. 6. This ratio captures a trade-off wherein the electrical resilience conferred to each sample in the input vector grows with the ratio between L and N. Available implementation technology places an upper limit on L. The larger N, the higher the bandwidth of payloads that can be accommodated. A designer is therefore motivated to make N very large. However, fixed L means that increasing N decreases the electrical resilience conferred to each sample in the input vector. In a preferred embodiment, L≥N.

(27) The encoding method of FIG. 1 repeats, for each chip interval τ and, equivalently, for each common index in the Codes, the steps of: i) modulating 308 each input sample 300 by the commonly indexed Chip 104 in the Code 304 corresponding to the input signal value's index in the input vector 350. If the payload signals are pulsatile, then the samples are continuous values and an embodiment of modulating is analog multiplication. If the Codes are binary (1/−1), then an embodiment of analog multiplication is conditional inversion. If the payload signals are digital, then the samples are numbers and an embodiment of modulating is digital multiplication. If the Codes are binary (1/−1), then an embodiment of digital multiplication is conditional negation, ii) summing 310 the modulation results 114 from step i) to form one of the ordered series 110 of output values 112, and iii) making available the output 108 produced by step ii), at a rate sufficient to enumerate all of the code 304 indices within the predetermined encoding interval,
wherein the ordered series 110 of values 112 resulting from step iii), one value for each code 304 index, in its entirety represents the input vector 350 within the predetermined number L of chip intervals τ.

(28) Only the signals appearing entirely within the high-speed time domain indicator 506 in FIG. 1 change during the process of encoding the input vector 350.

(29) FIG. 2 depicts a receiving, decoding, and distributing method and apparatus for reconstructing payload snippets from a received waveform, wherein an L-chip-interval time series 216 of received values 214 is decoded to yield an N-element output vector 352 of output signal samples 302. A full set of output values is produced once, after the L chip intervals τ allocated to receive the output vector 352.

(30) The decoding method of FIG. 2 relies on a code book 356. The code book is a set of N mutually orthogonal L-Chip 206 Codes 202, each of which should probably be a Spreading Code. The L indices of the Codes correspond to the L chip intervals τ allocated to receive the output vector 352.

(31) At the beginning of each decoding cycle (on ¥0), initialize the output values 302 each to 0.

(32) During each chip interval τ, the received value 214 is correlated 334 by the correspondingly indexed Chip 206 of the Code 202 whose index in the code book 356 corresponds to the index of the output value 302 in the output vector 352. If the payload signals are pulsatile, then the samples are continuous values and an embodiment of correlating is analog multiplication. If the Codes are binary (1/−1), then an embodiment of analog multiplication is conditional inversion. If the payload signals are digital, then the samples are numbers and an embodiment of correlating is digital multiplication. If the Codes are binary (1/−1), then an embodiment of digital multiplication is conditional negation.

(33) All L correlation results 204 at each input vector 350 index are summed 336 over the course of the encoding interval 2 to yield the respective output sample 302.

(34) The output vector 352 contains the reconstructed payload samples after the L chip intervals τ allocated to receive the output vector and makes them available as output vector values 344. The making available is adapted to any form of intra-equipment signalling.

(35) Only the signals appearing entirely within the high-speed time domain indicator 506 in FIG. 2 change during the process of encoding the output vector 352.

(36) Local-Site Transport of sample signals involves repeating this sequence of steps, potentially endlessly: Assembling an Input Vector from Input Payload Snippets; Encoding the Input Vector into a Transmitted Signal under control of Code Book; Transporting the Signal, which involves two concurrent activities; Transmitting the Signal (in the encoder assembly 326), and Receiving the Signal (in the decoder assembly 328); Decoding the Received Signal into the Output Vector, under control of the Code Book; and Distributing the Output Vector into Reconstructed Payload Snippets.

(37) Referring now to FIG. 3, element 1 represents end-to-end local-site transport (LST) 1 for sampled payloads includes an encoder assembly 326 connected over an electromagnetic (EM) pathway 314 to a decoder assembly 328. The encoder assembly receives an ordered series of input samples 504 and produces an analog waveform on the EM pathway. The decoder assembly receives an analog waveform from the EM pathway and produces an ordered series of output values 344, each of which is an approximation of its corresponding payload value. All of the encoding and decoding operations take place over the L steps of a predetermined transport interval, within the indicated high-speed time domain 506. In an embodiment, the EM pathway is a waveguide, enabling the maximum amount of energy to be conveyed.

(38) An encoder input vector 350 is assembled from successive samples 504 from each of one or more input payload signals 500 over a collecting interval 100 according to an arbitrary, pre-determined bijective encoder mapping function 346. The corresponding output payload signals 502 are assembled over a distributing interval 102 from the decoder output value vector 352 by a bijective decoder mapping function 348. In a preferred embodiment, the decoder mapping function is the inverse of the corresponding encoder mapping function.

(39) The encoder assembly 326 transforms the encoder input vector 350 into a series of values transmitted via the EM pathway 314 to the decoder assembly 328. The EM pathway connects the encoder assembly output terminal 338 to the decoder assembly input terminal 340. An impedance 316 terminates the EM pathway at the decoder assembly input terminal. The decoder assembly receives the propagated signal from the EM pathway and transforms the sequence of received values into the decoder output vector 352.

(40) The LST 1 shown in FIG. 3 is capable of injecting relatively large amounts of mains-supplied energy into the EM pathway 314. In an embodiment, the EM pathway is a waveguide.

(41) Without loss of generality, it is apparent to one skilled in the art that while the system is described as transporting payloads from encoder assembly 326 to decoder assembly 328 that information may also flow in the opposite direction over the EM pathway 314 with the implementation of a secondary decoder parallel to primary encoder 326 and attached to the transmission medium at 338 receiving information from a secondary encoder block parallel to primary decoder 328 and driving the line at 340 to implement bi-directional transmission of information, either digital or pulsatile. The primary distinction of primary vs. secondary encoder/decoder is a distinction of amount of information flow. The secondary information flow being for example command and control signals, audio signals to drive a speaker or similar apparatus. This is known as UTC (Up The Cable) communications and is comprised of much lower information content. With the use of a separate code sequence for the UTC communications the information in the form of digital or pulsatile signals may flow in the opposite direction, such separate code sequence being orthogonal to the primary code sequences.

(42) FIG. 4 illustrates one of the N! possible permutations of the permuter 346 between Collection Interval 500 samples 504 and encoder input vector 350 positions 300. This schema allows for any number of payload signals in the list implied by the ellipses between β and ω on the left-hand side of the drawing, and for each payload signal to contribute any number of samples from its snippet to the input vector during each Collection Interval.

(43) FIG. 4 shows a straightforward round-robin permutation performed within the permuter 346, wherein a next sample from each signal 500 in the set of payload signals 504 α, β, . . . , ω is assigned in turn to the next available index in the encoder input vector 350, until all N input vector locations 300 have been filled. The numbered circles indicate the order in which the input payload snippet samples are selected for including in the encoder input vector. Exactly N samples are collected during the Collection Interval.

(44) Although there are N! equally good choices for permutation implemented by the permuter 346, the decoder permuter 348 implements the inverse of the permutation implemented by the corresponding encoder. Ensuring agreement regarding such details is the subject of international standards, for future implementation.

(45) The schema drawn in FIG. 4 applies to many possible types of signal. For example, there could be a single payload signal, consisting of a representation of video wherein each successive sample is a color value (for example, 3 (R/G/B) per pixel). Another example is also a single payload signal, this one payload signal consisting of color values from several interleaved independent video signals. Further examples include diverse types of signal, for example, video, audio, chemical, mechanical/haptic, and so forth. An embodiment of one such hybrid example includes different numbers of samples from/to each payload signal during each transport interval. Further examples include each of the four types of signal (digital, analog, pulsatile, and neural) solo or in concert.

(46) FIG. 5 illustrates an especially common special case of the general schema described in FIG. 4. In this example, the payload consists of 3 signals 500, representing the R, G, and B color planes, respectively, of a single RGB-based video signal. N, the number of elements in the encoder input vector 350, happens to be 8. This example shows the round-robin assignment during the transmission of a first transport interval.

(47) Further to the example begun in FIG. 5, FIG. 6 illustrates round-robin assignment during the transmission of the second transport interval.

(48) Referring now to FIG. 7, an encoder assembly 326 receives input signal samples 504 from mapping 346 and drives a signal through its output terminal 338 onto an EM pathway 314. The encoder assembly includes an input vector memory 350 for receiving and storing all of the input signal samples and a Code Book memory 354 for receiving and storing a predetermined code set, one Code 304 associated with each input sample 300.

(49) The encoder assembly 326 data path features a plurality of modulators 308, one per input sample 300, which is re-used over and over, once per chip interval τ. On each cycle of the transmit clock in the high-speed domain 506, each modulator applies the correspondingly indexed Chip 306 to its correspondingly indexed input sample, and the summing circuit 310 combines all modulator outputs 508 to produce a next value 108 for transmission by the line driver 312 via the output terminal 338 into the EM pathway 314. In an embodiment, the EM pathway is a waveguide, enabling the maximum amount of energy to be conveyed.

(50) If the input payload signals 500 are pulsatile, then the input samples 301 are continuous values and an embodiment of the modulator 308 is an analog multiplier. If the Codes 330 are binary (1/−1), then an embodiment of the analog modulator is a conditional inverter. If the payload signals are digital, then the samples are numbers and an embodiment of the modulator is a digital multiplier. If the Codes are binary (1/−1), then an embodiment of the digital multiplier is a conditional negater.

(51) An application payload signal 500 of longer duration than a single collecting interval 100 is encoded over the course of several collecting intervals and thus over the course of a corresponding number of encoding intervals 12 as well as a corresponding number of transport intervals 2. In a preferred embodiment, the parameters defining the encoder assembly 326, including collecting interval, encoding interval, transport interval, N 8, L 10, code book 354, and permuter 346 permutation all remain constant throughout the steps involved in the processing of one set of input payload samples 504 corresponding to a single set of input vector 350 contents. In one embodiment of the encoder assembly, all of the encoding parameters are “hard coded” and cannot be changed. Because the encoding of one input vector is logically independent from the encodings of all previous and of all following input vectors, the encoding parameters may change from one input vector's worth of payload samples to the next. Therefore, in another embodiment of the encoder assembly, any of the encoding parameters may be varied from one collecting interval to the next under algorithmic control, for example in response to changes in payload characteristics, EM pathway 314 characteristics, and/or application requirements.

(52) For a digital embodiment of the encoder modulator 308 wherein the encoder Chips 306 happen to be constrained to be binary (for example, 1 and 0), one embodiment of the modulator comprises a combinatorial circuit that inverts the signed integer representation of each input sample 342. A corresponding embodiment of the line driver 312 effects a digital to analog conversion.

(53) For an analog embodiment of the encoder modulator 308 wherein the encoder Chips 306 happen to be constrained to be binary (for example, 1 and −1), one modulator embodiment comprises a commutating modulator, such as the example shown in FIG. 8.

(54) The example modulator 308 shown in FIG. 8 applies the Chip input 104 to the corresponding input sample 342 to produce modulated output 508. This style of modulator, known as a commutating modulator, inverts the input sample 342 based upon the polarity of the Chip input 104. Coupled inductors 606 and 608 impose a galvanically isolated copy of the input sample 342 across commutation diodes 612 and 610 relative to a center tap connected to signal 602, each of diodes 612 and 610 conduct in turn based upon the polarity of bias imposed by signal 626. The Chip input 104 imposes a differential signal to the center tap of inductor 608, and one of the terminals of inductor 608 through signal 628. In one of the two differential polarities of Chip input 104, current flows through inductor 622 to signal 626, then through forward biased diode 612 into inductor 608, out of the center tap of inductor 608 onto signal 602, through inductor 616 to complete the current loop, according to Kirchhoff's circuital laws. On the opposite polarity of Chip input 104, current flows through inductor 616 to signal 602 and thereby onto the center tap of inductor 608. The signal emerges from inductor 608 and flows through forward biased diode 610 and onto signal 626, whereupon the current travels back through inductor 622 thus again completing the current loop according to Kirchhoff's circuital laws. It should be noted that the circuit direction in these two cases flows in opposite directions. Capacitors 618 and 620 are DC removal capacitors that ensure that the direction of current flow in signal 628 is converted correctly to a positive or negative polarity and biases the inductor 608 accordingly. Input sample 342 is coupled onto the above mentioned biasing signal flows. This coupled signal then flows out of coupled inductor 608 and through one of two established paths originating from the center tap 602 and exiting from one or the other of the terminals of inductor 608, there by establishing positive and negative signal representation through polarity of biasing signal imposed on 626. Capacitor 614 is a DC blocking capacitor that removes DC components from output signal 624.

(55) Referring now to FIG. 9, a decoder assembly 328 receives a signal from the EM pathway 314 at its input terminal 340. In an embodiment, the EM pathway is a waveguide, enabling the maximum amount of energy to be conveyed. The EM pathway is terminated by terminating impedance 316. The signal entering the decoder assembly is received by line amplifier 322, which is controlled through a feedback path by an equalizer 324.

(56) The output vector 352 is developed by the decoder 512 over the course of the decoding interval by accumulating partial contributions in the storage elements 302 during each chip interval 500 of the concurrent high-speed operations taking place inside of area 506. For each output vector 352 index, the decoder assembly 328 also comprises one Code 330 at a corresponding index in the Code Book memory 356, one correlator 334, and one integrator 336.

(57) Before beginning to decode an ordered series of received values, the output vector 352 entries 302 are cleared (by storing the value 0 in each. Subsequently, during each predetermined chip interval τ allocated to decoding the output vector, for each output vector index, correlate using the correlator 334 the received value 214 produced by line amplifier 322 with the correspondingly indexed Chip 332, and gather using the summing circuit 336 the correlation result 702 with the contents of the corresponding output sample memory 302.

(58) For a digital embodiment of the decoder 512 wherein the Chips 332 happen to be constrained to be binary (for example, 1 and 0), one embodiment of a correlator 334 comprises a combinatorial circuit that inverts the signed integer representation of each received value 214 according to the Chip 332. A corresponding embodiment of the amplifier 322 effects an analog-to-digital conversion.

(59) For an analog embodiment of the decoder 512 wherein the Chips happen to be constrained to be binary (for example, 1 and −1), a correlator might consist of an analog modulator, such as the example shown in FIG. 8.

(60) The output of each correlator 334 is integrated, together with the contents of its corresponding output sample memory 302, by the corresponding integrator 336. For a digital embodiment of the decoder, the integrator might be a straightforward combinatorial adder. For an analog embodiment of the decoder, one embodiment of an integrator comprises an op-amp-based integrator.

(61) If the reconstructed payload signals 502 are pulsatile, then the output samples 303 are continuous values and an embodiment of the correlator 334 is an analog multiplier. If the Codes 332 are binary (1/−1), then an embodiment of the analog correlator is a conditional inverter. If the payload signals are digital, then the samples are numbers and an embodiment of the correlator is a digital multiplier. If the Codes are binary (1/−1), then an embodiment of the digital correlator is a conditional negater.

(62) The correlation spike detector 320 monitors the outputs of the array of decoder correlators 334. In one embodiment all decoder assembly 328 functional elements are synchronized by a clock recovery circuit 318, which monitors the output of the line amplifier 322 as well as the output of the correlation spike detector to acquire and track carrier synchronization.

(63) SSDS is different from what is claimed in this disclosure: SSDS is a technology for communicating over long distances, versus the relatively limited distances spanned by LSTs. SSDS is applied when nearly every bit of a digital signal must be conveyed correctly, versus the satisficing approximations actually required of LSTs for many applications, including most human-viewing applications. SSDS is generally applied for single signal streams through an EM pathway which is often in free space, whereas LST carries one payload through an EM pathway which is often a waveguide.

(64) SSDS-CDMA is different from what is taught in this disclosure: In prior SSDS-CDMA, the encoded values are transmitted asynchronously from one another; by contrast, the LST disclosed herein synchronously encodes all values in a vector of N payload signal sample values as a series of L values conveyed across the EM pathway. Prior SSDS-CDMA seeks to hide the transmitted signals in the ambient noise floor, for minimum energy consumption, minimum potentially harmful EM radiation, and minimum probability of intercept; by contrast, the LST disclosed herein sends the maximum energy into the EM pathway that is permitted by relevant FCC/CE/CCC regulations. Prior (bit-serial) SSDS-CDMA relies on Chip-phase-shifted Code variants to differentiate amongst transmitters; by contrast, the encoder and decoder pair claimed herein uses orthogonal Code Books to minimize Intertrack Interference (II). An orthogonal Code Book may contain non-spreading Codes. The Identity matrix (sketched in FIG. 15) is an example of one such Code Book. One embodiment of an orthogonal Code Book contains spreading Codes, such that 1) transmission of each input/output vector sample enjoys the resiliency benefits of SSDS against aggressors and 2) for signals destined for sensory perception, transforming electrical imperfections as well as any II into perceptually benign artifacts.
Acquisition and Tracking of Synchronization Information in SSDS-CDMA Systems

(65) In any SSDS communication system, the receiver needs to be synchronized with the transmitter. Typically, the synchronization takes place in two parts: an initial coarse synchronization, also known as acquisition, followed by a finer synchronization, also known as tracking. There are many sources of error in the acquisition of synchronization, however in the embodiments disclosed herein, application issues of Doppler shift, multipath interference and some of the subtler effects which impact prior SSDS-CDMA are not present due to the relatively constrained nature of most infrastructure EM pathways.

(66) There is an additional benefit in which the initial chip rate, also known as the repeat rate, during the transport interval will be controlled by crystal oscillators or other accurate time sources. On the receive side, there are also be similar crystal oscillators or other or other accurate time sources, such that the difference in the fundamental frequency will be on the order of only hundreds of parts per million. Additionally, the sequence lengths of the pseudo noise generation circuits are not overly large, inasmuch that the repeat length is relatively short. All these factors add up to a system that can be simple to implement, and therefore low cost.

(67) The encoding/decoding system admits aforementioned simplifications, allowing us to forego a lengthy initial acquisition procedure. The receiver will be running close to the chip rate of the transmitter as well as the relative phase of the PN generator in the receiver can be easily acquired. In fact, the circuit implemented is simply a tracking system that acquires the relative phase of the receiver in respect to the transmitter with a slight variation on the ability to change frequency to match frequency of the transmission circuit.

(68) The synchronization acquisition system can be described as a sliding correlator that takes as inputs the received signal from the media as well as output from a PN generator that is local to the receiver. The local PN generator is driven from a PLL or phase lock loop which has a narrow band of frequency diversity, i.e. it natively will run at close to the target frequency and has a band of control around that center frequency. The output from the sliding correlator is analyzed to determine whether or not a lock condition has been achieved or if the frequency is either too high or too low, this lock detector then drives a PLL to either speed up or slow down first to stay the same in a feedback loop.

(69) The sliding correlator can be implemented as either a sampled and digitized representation of the incoming signal in which case the correlation is formed in digital logic. Another implementation of the sliding correlator can be as switched analog circuitry, in which in this case the incoming signal is sampled and the correlation is performed in switched capacitor circuitry.

(70) One classical technique in the acquisition process would be to have course phase alignment accomplished through searching through the various taps or delays, of the receiver PN generator and subtle phase frequency alignment being accomplished to the PLL. However, in an embodiment of the system, the time required to search through all of the available taps in the PN sequence generator is relatively short. Classically one might search amongst the various taps of the PN generator to find a correlation spike that is relatively close and then fine-tune this correlation by changing the frequency of the PLL. Through this it becomes possible to accomplish both coarse and fine adjustments. Because an embodiment of the system is relatively unconstrained, it becomes possible simply to slide the phase by changing the frequency and accomplishing both the course and the fine adjustments through the changing of the PLL.

(71) A further embodiment allows the transmitter to send a training sequence that has predetermined characteristics to facilitate synchronization acquisition and tracking. This training sequence may occur at the beginning of every grouping of data video data or it actually may exist as a sub band, i.e. modulated by a further code orthogonal to all of the codes in the code book applied to the payload snippets and transmitted at the same time, continuously. The independent training sequence, or sub-band, serves as a probe of the EM characteristics of the EM pathway, which may in turn be referenced for parametric tuning of signal correction circuits, such as pre-emphasis. Henceforth this signal is referred to as the “probe signal” without loss of generality. This probe signal may be held constant over k transport intervals, for some predetermined k, and its associated code made k*L chips long. As with the payload samples in the input vector, this probe signal may be implemented either with discrete (digital) or with continuous (pulsatile) representations. This approach enhances the resilience of the probe track to noise, interference, and reflections. In this application, the probe signal is particularly powerful in facilitating acquisition and tracking because the probe signal can be made to have a constant amplitude that allows channel attenuation to be measured directly.

(72) Another preferred embodiment is the parallel correlation system shown in FIG. 11. This system analyzes adjacent taps in the PN sequence generator. By studying three adjacent taps and the correlation relating to each of those individual taps, the lock detection algorithm is greatly simplified.

(73) In a further embodiment, the receiving circuit is adapted to retransmit a phase-aligned and synchronized signal back to the transmitting circuit in an independent sub-band. Completing the control loop in this manner allows the transmitter to transition, an embodiment, between providing the probe signal versus encoding payload snippets. Upon initial power-up, the transmitting circuit transmits the probe signal until it acquires a sub-band signal that is returned from the receiving circuit. When the returned signal is received, the transmitting circuit then starts transmitting data according to the received parameters. This closed-loop control system allows a robust and self-calibrating LST to be implemented.

(74) LST Optimization

(75) In an LST, a transmitter sends energy over an EM pathway to a receiver. The LST payload comprises one or more sampled signal snippets. For each set of payload snippets, the LST assembles an input vector, encodes the input vector, transmits a signal into the imperfect EM pathway, receives a signal from the other end of the EM pathway, decodes the received signal into an output vector, and distributes the output vector to reconstructed payload snippets. The exactness of the correspondence between the reconstructed payload and the input payload is determined entirely by the electrical quality of the EM pathway and by the encoder assembly and decoder assembly implementations.

(76) The electrical quality of the EM pathway in turn depends both upon physical variation in materials and assemblies and upon environmental interference. As a result, the signal received at the decoder assembly differs from the signal transmitted by the encoder assembly. The difference between the transmitted and the received signals is determined by, for example, roll-off, reflections due to impedance mismatches, and impinging aggressor signals.

(77) A reconstructed payload signal 502 longer than a single distributing interval 102 is encoded over the course of several distributing intervals and thus over the course of several decoding intervals 14 and correspondingly several transport intervals 2. In a preferred embodiment, the parameters defining the decoder assembly 328, including transport interval, decoding interval, distributing interval, N 8, L 10, code book 356, and permuter 348 permutation all remain constant throughout the steps involved in processing of one set of reconstructed payload samples 357 corresponding to a single set of output vector 352 contents. In one embodiment of the decoder assembly, all of the decoding parameters are “hard coded” and cannot be changed. Because the decoding of one output vector is logically independent from the decodings of all previous and of all following output vectors, there is no reason that the decoding parameters cannot change from one output vector's worth of reconstructed payload samples to the next. Therefore, in another embodiment of the decoder assembly, any of the decoding parameters may be varied from one distributing interval to the next under algorithmic control, for example in response to changes in payload characteristics, EM pathway 314 characteristics, and/or application requirements.

(78) In another embodiment of an analog version of the decoder assembly 328, the analog portion can be implemented as a switched capacitor circuit. Given that the operation of this circuit will entail the use of sample and hold circuits, multiplier circuits and a pipeline type operation, it should be obvious to those skilled in the art the similarities to state-of-the-art ADC design. Indeed, one such implementation of the analog decoder assembly allows for accommodating any amplitude representation, from binary through n-ary to continuous, through the simple selection of thresholding levels in the pipeline operation of the decoder assembly. In an embodiment, a decoder assembly is design parametrically reconfigurable to accommodate either digital signals or pulsatile signals, thereby enabling system flexibility.

(79) FIG. 10 shows the architecture of an embodiment of one synchronization acquisition and tracking circuit, which can be described as a sliding correlator. The key input is the received signal 214, and the key output is the clock signal 826. The circuit in FIG. 10 comprises a PN generator 814, clocked by a phase-locked loop (PLL) 810, which is adjusted finely by the correlation peak detector 320. The PN generator is designed so as to have a narrow band of frequency diversity, i.e. it natively will run at close to the target frequency and has a band of control around that center frequency. The output 824 from the sliding correlator is analyzed in the correlation peak detector to determine whether or not a lock condition has been achieved or if the frequency is either too high or too low. This lock detector then adjusts the PLL frequency to servo on synchronization.

(80) The sliding correlator shown in FIG. 10 can be implemented as either a sampled and digitized representation of the incoming signal in which case the correlation is formed in digital logic. Another implementation of the sliding correlator can be as switched analog circuitry, in which in this case the incoming signal is sampled and the correlation is performed in switched capacitor circuitry. One embodiment simply adjusts the phase by changing the frequency and accomplishing both the coarse and the fine adjustments by adjusting the PLL frequency.

(81) In an alternative embodiment, the encoder assembly 326 sends a training sequence with known characteristics as a preamble to a series of vector transmissions, so as to facilitate synchronization acquisition and tracking. This training sequence may occur at the beginning of every vector transmission, or it may be transmitted as an independent snippet along with the input payload snippets. Sending the training sequence as an independent payload signal allows this probe signal to characterise the quality of transmission media. Such characterization data is used for various signal correction parameters like pre-emphasis. Additionally, the training sequence signal could also be of much longer period than one collecting interval, increasing resilient against noise and interference. In the present disclosure, the training sequence is particularly powerful in facilitating acquisition and tracking simply because the training sequence can be made to have a constant amplitude.

(82) An example of a parallel-correlation synchronization acquisition and tracking system is shown in FIG. 11. This system analyses adjacent taps 902, 904, and 906 in the PN sequence generator 814. By evaluating three adjacent taps concurrently, as well as the correlation relating to each of those individual taps, in the correlation spike detector 320, the lock detection algorithm is greatly simplified.

(83) In a further embodiment, the receiving circuit is adapted to retransmit a phase-aligned and synchronized signal back to the transmitting circuit in an independent sub-band. Completing the control loop in this manner allows the transmitter to transition, an embodiment, between providing the probe signal versus encoding payload snippets. Upon initial power-up, the transmitting circuit transmits the probe signal until it acquires a sub-band signal that is returned from the receiving circuit. When the returned signal is received, the transmitting circuit then starts transmitting data according to the received parameters. This closed-loop control system allows a robust and self-calibrating LST to be implemented.

(84) FIG. 12 shows a straightforward round-robin permutation of the permuter 348, wherein a next sample 302 from each successive index in the decoder output vector 352 is distributed in turn to the next sample 804 in the next signal 502 in the set of reconstructed payload snippets α′, β′, . . . , ω′, until all N output vector locations have been exhausted. There are potentially different numbers of samples per reconstructed payload snippet, all distributed during the one distributing interval. The numbered circles indicate the order in which the decoder output vector contents are distributed to reconstructed payload snippets during the distributing interval. Exactly N samples are distributed during the distributing interval.

(85) Although there are N! equally good choices for permuter 348 permutation, successful payload transport demands that the decoder 512 permutation implement the inverse of the encoder 510 permutation 510 (shown in other figures). Ensuring agreement regarding such details is appropriately the subject of international standards, rather than of the present disclosure.

(86) The schema drawn in FIG. 12 applies to many possible types of signal. For example, there could be a single payload signal, consisting of a representation of video wherein each successive sample is a color value (for example, 3 (R/G/B) per pixel). Another example is also a single payload signal, this one consisting of color values from several independent video signals are interleaved. Further examples include diverse types of signal, for example, video, audio, chemical, mechanical/haptic, and so forth. An embodiment of one such hybrid example includes different numbers of samples from/to each payload signal during each transport time interval. Further examples include each of the four types of signal (digital, analog, pulsatile, and neural) solo or in combination.

(87) FIG. 13 illustrates round-robin assignment of samples from indices in an 8-element decoder output vector to a parallel-RGB output video signal arising from reception of a first transport interval.

(88) FIG. 13 illustrates an especially common special case of the general schema described in FIG. 12. In this example, the reconstructed payload consists of 3 signals 502, representing the R, G, and B color planes, respectively, of a single reconstructed RGB-based video signal. N, the number of elements in the decoder 512 output vector 352, happens to be 8. This example shows the round-robin assignment during a given distributing interval.

(89) Further to the example begun in FIG. 13, FIG. 14 illustrates round-robin assignment during the immediately following distributing interval.

(90) FIG. 15 shows the structure of a binary code book which is a subset of the identity matrix, for the case where L=N+3. The chip index j 916 runs from 0 to L−1 horizontally across the figure, and the input/output vector index i 914 runs from 0 to N−1 vertically down the figure.

(91) FIG. 16 shows an example of a 127×127 binary code book whose codes is each a unique rotation of a common PN sequence. In the figure, a black square corresponds to a “1” value, while a white square corresponds to a “−1” value. The matrix for pulsatile modulation is constructed per the following steps: 1. Instantiate the L×L identity matrix 2. Keep only the 1.sup.st N rows 3. Convert 0 entries to −1 values 4. The result is the example code book depicted in FIG. 16

(92) FIG. 17 shows an example of a 128×128 binary code book, which is a Walsh-Hadamard matrix. In the figure, a black square corresponds to a “1” value, while a white square corresponds to a “−1” value.

(93) FIG. 18 shows an example of a 128×128 binary code book, which is constructed by convolving a Walsh-Hadamard matrix with a near-PN sequence. In the figure, a black square corresponds to a “1” value, while a white square corresponds to a “−1” value.

(94) In an embodiment, the payload signals 500 and 502 comprise video signals, for example as illustrated in FIG. 5, FIG. 6, FIG. 13, and FIG. 14 for the case of fully populated R/G/B color planes. FIG. 19 shows one embodiment wherein the subject of this disclosure is applied to (a class of) video systems. The architecture depicted in FIG. 19 comprises a predetermined number C of cameras 516 and another predetermined number D of displays 518. The architecture depicted in FIG. 19 also includes a media processing unit (MPU) 548. The MPU in turn contains a video processor 536, non-volatile storage 560, with which the video processor exchanges storage signals 562, and a Wide Area Network interface 544, through which the video processor communicates with the Internet 576 via Internet Protocol signals 546.

(95) The camera 516 depicted in FIG. 19 comprises a lens 520, which refracts incident light 528 to project focused light 534 onto a focal plane 554 occupied by an image sensor 522. The image sensor produces an output signal 524 which comprises an ordered series of light measurements, each measurement corresponding to a geometric location within the focal plane, wherein each measurement is acquired during a predetermined image sensor exposure interval 4. In one pipeline-balanced embodiment, the image sensor exposure interval equals the transport interval 2. The camera also includes an encoder assembly 326. 538 is a circuit that adapts image sensor output samples as an input payload signal for the encoder.

(96) The image sensor 522 output signal 524 is intrinsically pulsatile; converting to digital signals uses an additional analog-to-digital converter circuit, which cannot possibly add fidelity while certainly adding non-zero manufacturing cost. A simplest embodiment of the subject of this disclosure conveys pulsatile signals directly, without requiring analog-to-digital conversion of the light measurements, resulting in fit-for-purpose transmission of high-resolution video signals at least cost compared to prior arrangements.

(97) The display 518 shown in FIG. 19 comprises a decoder assembly 328, a circuit 540 that adapts the decoder assembly output (reconstructed display control signal snippets) to the input 526 of display element array controller 556. The array controller generates a series of brightness control values 558. Each brightness control value determines the brightness maintained during each predetermined display array refresh interval 6 of the light-emitting element at each geometric location within the array 530 of display elements. In one pipeline-balanced embodiment, the display array refresh interval equals the transport interval 2. The display array consists of elements, such as certain kinds of diodes, which emit light 552. Viewers' brains interpret such activity over time as moving images.

(98) In a video embodiment of FIG. 19, the centrepiece of the video system depicted in is the central processing unit (MPU) 548, which in turn is based on a video processor 536. The MPU receives a signal from every camera 516 via LST 1, and the MPU transmits a signal to every display 518 in the system via LST 1. All of the camera signals and all of the display signals each is independent from all other video signals in the system. A potentially trivial circuit 568 adapts each decoder assembly output 564 (reconstructed camera output signal snippets) to the data format 570 required for the video processor. Similarly, a potentially trivial circuit 574 adapts prepared display input signals 572 from the data format of the video processor to an input payload signal 566 destined for the corresponding display. Circuits 568 and 574 are well known in the art.

(99) In an embodiment, the MPU 548 performs a variety of operations on video, including decoding stored content 562 retrieved from non-volatile memory 560, storing compressed video signals 562 to non-volatile memory, and/or exchanging Internet Protocol signals 546 with the Internet 576 via a WAN Modem 544. A bidirectional converter 542 translates between Ethernet packets and the pulsatile or digital signals occupying the datapaths of the video processor.

(100) In one embodiment, the video processor 536 is a CPU. In another embodiment, the video processor is a GPU. The video processor may be implemented either with digital datapaths or with pulsatile datapaths. Digital datapaths demand A/D on inputs and D/A on outputs and are therefore intrinsically less efficient for video than pulsatile datapaths.

(101) A broad diversity of common video systems are seen to be parametric variants of the schema sketched in FIG. 19, for example: In one embodiment of a home entertainment system circa 1990: C=0—there are no cameras. D=1—a CRT display is encased in a box that sits on a table. The MPU 548 is a tuner/amplifier circuit assembly, the EM pathway 314 is coaxial cable, and the LST 1 is PAL. In one embodiment of a home entertainment system circa 2016, C=2—a Kinect system includes stereo monochrome computer vision. D=1—an HDMI display hangs on the wall. The MPU 548 is a gaming machine such as, for example, a PlayStation™ of Sony or Xbox™ of Microsoft, the EM pathway 314 is HDMI cable, and the LST 1 is HDMI. In one possible embodiment of a home entertainment system, for example one implementing iVR™ (“immersive virtual reality”), C=256—high-resolution cameras provide 3D 360-degree machine vision inputs, making a whole new range of inputs available for gesture- and movement-based interfaces. D=2048—every solid wall, ceiling, and floor is constructed from flexible, rugged display panels. The MPU 548 is a computationally enhanced variant of a PlayStation or Xbox. The EM pathway 314 is any American Wire Gauge (AWG) wire pair, and the LST 1 is the subject of the present disclosure. This embodiment enables an experience that is qualitatively different from what is heretofore expected of pixel-rich Internet content. In one embodiment of a passenger vehicle system, C=8—a variety of infrared (IR) and ultraviolet (UV) and visible light sensors collects data for machine vision analysis for safety. D=4—displays are provided on the dash and in front seat head rests, for rear passenger entertainment. The MPU 548 is the engine control unit (ECU). The EM pathway 314 is CAT-3, and the LST 1 is LVDS. In one possible embodiment of a passenger vehicle system, C=32—a variety of IR and UV and visible light sensors collects data for machine vision analysis for safety, and video-intensive Internet interaction is enabled for passengers. D=64—displays are provided on all solid surfaces and on exterior glass and on the dash, both for control and for passenger entertainment. The MPU 548 is the engine control unit (ECU). The EM pathway 314 is inexpensive cable, and the LST 1 is the subject of the present disclosure. This embodiment enables passengers to enjoy iVR entertainment experiences, while the driver can take advantage of the most responsive possible heads-up display for controlling the vehicle. In one embodiment of a retail signage video system (e.g., fast food restaurant menus), the MPU 548 is a tower PC or server. The EM pathway 314 is CAT-5/6, and the LST 1 is HDBaseT. In one possible embodiment of a retail signage video system, the MPU 548 is a tower PC or server. The EM pathway 314 is any AWG wire pair, and the LST 1 is the subject of the present disclosure. This embodiment allows displays 518 to be placed further away from the MPU, thus saving costs by allowing a single MPU to accommodate a larger number of displays. Moreover, the cables are far less expensive, and it is easy to terminate such cables in the field (currently a major barrier to HDMI enabling iVR). In one embodiment of an HD video surveillance system, the MPU 548 is a DVR. The EM pathway 314 is coaxial cable, and the LST 1 is Analog HD. In one possible embodiment of an 8K video surveillance system, the MPU 548 is a DVR. The EM pathway 314 is any AWG wire pair, and the LST 1 is the subject of the present disclosure. This embodiment carries high-resolution video cost-effectively over legacy infrastructure cabling. Other embodiments that can be shown to be parametric instantiations of the schema of FIG. 19 include a circa 1970 cinema system wherein C=0 and D=1, an example surround-view system wherein C=0 and D=8, a futuristic iVR cinema system wherein C=64 and D=64, an HD rock concert video system wherein C=8 and D=8, and an 8K rock concert video system, wherein C=128 and D=128, that enables high-resolution live experiences incorporating video feeds of performers, audience members, prepared video signals, and synthetically generated video signals.

(102) The subject of the present disclosure is aspects of an LST 1 that transfers any type of sampled signal 500 along an EM pathway 314. In many applications requiring transport of video, audio, and other kinds of data signals, it is desirable also to be able to transport information along the EM pathway in the direction opposite to that of the main payload information flow. For example, the MPU 548 shown in FIG. 19 may benefit from the ability to send control and configuration information to sensors, including cameras and microphones. The disclosed LST does not preclude low-bandwidth upstream communication.

(103) The encoder assembly 326 encodes a vector of N samples every encoding interval. If we call the number of encoding intervals per second f (so f=1/encoding interval), the throughput of the encoder assembly is Nf samples per second, making available Lf samples per second for transmission into the EM pathway 314, where L>=N. For example, 1920×1080 1080p60 HD Video, is approximately 2 million pixels or 6 million samples per frame, or 360 million samples per second for an RGB encoding of each pixel. That tells us Nf=360e6=0.36e9. It might reasonably be expected that Lf=1 GHz=1e9. Then N/L=0.36, or for L=128, N=46. The encoder assembly transmits the entire ordered series of output values during the transport interval 1.

(104) FIG. 20 shows an example oscilloscope trace of a signal arriving from the EM pathway 314 at the decoder assembly 328 input terminal 340. The vertical scale is voltage, and the horizontal scale is 100 ps oscilloscope measurement interval. In FIG. 20, 20 oscilloscope measurement intervals correspond to one chip interval τ.

(105) Throughout the specification and the claims that follow, unless the context requires otherwise, the words “comprise” and “include” and variations such as “comprising” and “including” will be understood to imply the inclusion of a stated integer or group of integers, but not the exclusion of any other integer or group of integers.

(106) The reference to any prior art in this specification is not, and should not be taken as, an acknowledgement of any form of suggestion that such prior art forms part of the common general knowledge.

(107) It will be appreciated by those skilled in the art that the invention is not restricted in its use to the particular application described. In particular, while some of the examples shown are for RGB full-color images, the subject of this disclosure applies regardless of the depth/number of payload signals or color space of any video in the payload, including all variants of chroma/luma separated (and chroma-sub-sampled) color spaces (e.g., YUV, YUV 4:2:0, etc.), as well as Monochrome (i.e., just Y). Neither is the present invention restricted in its preferred embodiment with regard to the particular elements and/or features described or depicted herein. It will be appreciated that the invention is not limited to the embodiment or embodiments disclosed, but is capable of numerous rearrangements, modifications and substitutions without departing from the scope of the invention as set forth and defined by the following claims.