Ground terminals via remote digital-beam-forming networks for satellites in non-geostationary orbit
11552699 · 2023-01-10
Assignee
Inventors
- Donald C.D. Chang (Thousand Oaks, CA)
- Juo-Yu Lee (Westlake Village, CA, US)
- Steve K. Chen (Pacific Palisades, CA, US)
Cpc classification
H04B10/2575
ELECTRICITY
H04N7/20
ELECTRICITY
H04W52/42
ELECTRICITY
H04L27/265
ELECTRICITY
International classification
H04B7/185
ELECTRICITY
H04B10/2575
ELECTRICITY
H04W52/42
ELECTRICITY
Abstract
A MIMO basestation for a cellular communications system comprises a remote indoor processing facility coupled to an outdoor RF tower via optical fibers. The remote indoor processing facility includes a bank of RF modulators to modulate signal streams; a remote MIMO transmitting processor that includes a remote digital beam-forming network to transform the modulated signal streams into transmit beam signals; a pre-processor to perform a wavefront multiplexing transform on the transmit beam signals to generate wavefront multiplexed beam signals, each of the wavefront multiplexed beam signals being a linear combination of the transmit beam signals; and RF-to-optical drivers to perform optical modulating functions on the wavefront multiplexed beam signals to generate optical waveform streams.
Claims
1. A MIMO basestation for a cellular communications system comprising: a remote indoor processing facility comprising: a bank of RF modulators configured to modulate signal streams; a remote MIMO transmitting processor comprising a remote digital beam-forming network configured to receive the modulated signal streams and generate transmit beam signals; a pre-processor configured to perform a wavefront multiplexing transform on the transmit beam signals to generate wavefront multiplexed beam signals, each of the wavefront multiplexed beam signals being a linear combination of the transmit beam signals; and RF-to-optical drivers configured to perform optical modulating functions on the wavefront multiplexed beam signals to generate optical waveform streams; and optical fibers configured to couple the RF-to-optical drivers to an outdoor RF tower.
2. The MIMO basestation of claim 1, wherein the remote indoor processing facility further comprises: a set of adaptive equalizers coupled to the pre-processor and configured to perform pre-distortion compensation for signals propagating in the optical fibers; and an optimization loop unit configured to control the set of adaptive equalizers.
3. The MIMO basestation of claim 1, wherein optical communications between the remote indoor processing facility and the outdoor RF tower through the optical fibers are via a Passive Optical Network standard or a wavelength division multiplexing (WDM) standard.
4. The MIMO basestation of claim 1, wherein the wavefront multiplexing transform comprises one of a Hadamard transform matrix, a Fourier transform matrix, an N-to-N orthogonal matrix where N is an integer greater than 1, or an N-to-N full-rank matrix where N is an integer greater than 1.
5. The MIMO basestation of claim 1, wherein the outdoor RF tower comprises: optical-to-RF converters configured to receive and optical demodulate the optical waveform streams to recover the wavefront multiplexed beam signals; a post-processor configured to perform a wavefront demultiplexing transform on the recovered wavefront multiplexed beam signals to recover the transmit beam signals, the wavefront demultiplexing transform being an inverse of the wavefront multiplexing transform; power amplifiers configured to amplify the recovered transmit beam signals; and an array antenna having a plurality of transmit elements configured to radiate the amplified transmit beam signals toward receiving elements of destinations in a multipath propagation environment.
6. The MIMO basestation of claim 5, wherein the outdoor RF tower further comprises: RF blocks coupled to inputs of the power amplifiers respectively, and configured to perform frequency up-converting, bandpass filtering and buffer amplifying on the recovered transmit beam signals.
7. The MIMO basestation of claim 5, wherein the remote digital beam-forming network is configured to form multiple shaped transmit beam signals pointing to various directions within a field of view of the transmit elements of the array antenna.
8. The MIMO basestation of claim 5, wherein the remote MIMO transmitting processor further comprises a digital MIMO processing assembly configured to measure channel state information by measuring dynamically a plurality of point-to-point transfer functions, each of the point-to-point transfer functions indicating an amount of a propagation phase delay and associated relative attenuation from one of the transmit elements to one of the receiving elements, the transmit elements and the receiving elements being identified by respective indices, the point-to-point transfer functions being specified as functions of the respective indices.
9. The MIMO basestation of claim 8, wherein the digital MIMO processing assembly is further configured to compute composited transfer functions by combining, for each of the composited transfer functions, a corresponding set of the point-to-point transfer functions.
10. The MIMO basestation of claim 9, wherein the digital MIMO processing assembly performs optimization processing on the composited transfer functions in terms of the respective indices of the transmit elements and the receiving elements to achieve point-to-multipoint performance constraints.
11. A MIMO basestation for a cellular communications system comprising: an outdoor RF tower comprising: an array antenna having a plurality of receiving elements configured to capture signal streams from user transmit elements in a multipath propagation environment; low noise amplifiers configured to amplify the captured signal streams; analog-to-digital conversion blocks configured to convert the amplified signal streams to digital signal streams; a pre-processor configured to perform a wavefront multiplexing transform on the digital signal streams, and generate wavefront multiplexed signal streams, each of the wavefront multiplexed signal streams being a linear combination of the digital signal streams; and RF-to optical drivers configured to perform optical modulating functions on the wavefront multiplexed signal streams to generate optical waveform streams; and optical fibers configured to couple the RF-to optical drivers to a remote indoor processing facility.
12. The MIMO basestation of claim 11, wherein the remote indoor processing facility comprises: optical-to-RF converters configured to receive and optically demodulate the optical waveform streams to recover the wavefront multiplexed signal streams; a post-processor for performing a wavefront demultiplexing transform on the recovered wavefront multiplexed signal streams to recover the digital signal streams, the wavefront demultiplexing transform being an inverse of the wavefront multiplexing transform; a MIMO receiving processor configured to process the recovered digital signal streams; and a bank of RF demodulators configured to demodulate the recovered digital signal streams and generate corresponding data streams.
13. The MIMO basestation of claim 12, wherein the MIMO receiving processor comprises a remote digital beam-forming network configured to receive the recovered digital signal streams and generate corresponding receive beam signals.
14. The MIMO basestation of claim 13, wherein the remote digital beam-forming network is configured to form multiple shaped beams pointing various directions within a field of view of the receiving elements of the array antenna.
15. The MIMO basestation of claim 12, wherein the remote indoor processing facility further comprises: a set of adaptive equalizers coupled to the post-processor and configured to perform distortion compensation for multichannel signals propagating in the optical fibers.
16. The MIMO basestation of claim 12, wherein the MIMO receiving processor is configured to process response signals sent by user transmit elements to measure channel state information.
17. The MIMO basestation of claim 12, wherein the MIMO receiving processor is configured to respond to probing signals sent by various user transmit elements with unique acknowledgement signals.
18. The MIMO basestation of claim 12, wherein the array antenna is configured to operate at current mobile cellular communications frequency bands or at frequency bands of a planned 5G cellular system.
19. The MIMO basestation of claim 11, wherein optical communications between the outdoor RF tower and the remote indoor processing facility through the optical fibers are via a Passive Optical Network standard or a wavelength division multiplexing (WDM) standard.
20. The MIMO basestation of claim 11, wherein the wavefront multiplexing transform comprises one of a Hadamard transform matrix, a Fourier transform matrix, an N-to-N orthogonal matrix where N is an integer greater than 1, or an N-to-N full-rank matrix where N is an integer greater than 1.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) The drawings disclose illustrative embodiments of the present disclosure. They do not set forth all embodiments. Other embodiments may be used in addition or instead. Details that may be apparent or unnecessary may be omitted to save space or for more effective illustration. Conversely, some embodiments may be practiced without all of the details that are disclosed. When the same reference number or reference indicator appears in different drawings, it may refer to the same or like components or steps.
(2) Aspects of the disclosure may be more fully understood from the following description when read together with the accompanying drawings, which are to be regarded as illustrative in nature, and not as limiting. The drawings are not necessarily to scale, emphasis instead being placed on the principles of the disclosure. In the drawings:
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(22) While certain embodiments are depicted in the drawings, one skilled in the art will appreciate that the embodiments depicted are illustrative and that variations of those shown, as well as other embodiments described herein, may be envisioned and practiced within the scope of the present disclosure.
DETAILED DESCRIPTION OF THE INVENTION
(23) Illustrative embodiments are now described. Other embodiments may be used in addition or instead. Details that may be apparent or unnecessary may be omitted to save space or for a more effective presentation. Conversely, some embodiments may be practiced without all of the details that are disclosed.
(24) Before describing embodiments of the present invention, a definition has been included for these various terms. These definitions are provided to assist in teaching a general understanding of the present invention.
(25) All figures illustrate forward direction implementations and key functions. Most of return direction implementations and key functions are similar and not shown.
(26) For conventional TDM-PON, a passive optical splitter is used in the optical distribution network. In the upstream or return direction, each ONU (optical network units) or ONT (optical network terminal) burst transmits for an assigned time-slot (multiplexed in the time domain). In this way, the OLT is receiving signals from only one ONU or ONT at any point in time. For K-muxing over a TDM PON, each ONU (optical network units) or ONT (optical network terminal) in the upstream or return direction continuously transmits K-muxed signals with unique WF vectors at low power level for all time-slots (multiplexed in the time domain).
(27) Structure of Passive Optical Network (PON):
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(29) An OLT 1200 further comprises three major function: a conventional multiplexing, an optical modulating or frequency converting, and an optical source. Referring to
(30) The purpose for the PON depicted is to deliver D1 data stream to a first user with a first of 32 ONUs 1300, ONU 1; to deliver D2 data stream to a second user with ONU 2, and so on. The total throughput of the PON 1100 will then be shared among the 32 users usually uniformly. For a total throughput capacity of 1 or 2.5 Gbps, each user shall get a maximum capacity of 31.25 or 78.125 Mbps, respectively.
(31) Referring to
(32) In an upstream direction (not indicated in
(33) The optical line terminal 1200 (OLT) is arranged between a central office (CO) processor and the optical dividers 1150. In the downstream direction, the OLT1200 can transform electronic data, output from the central office processor, into optical data sent to one of the optical dividers 1150 through the optical fiber 1160. The data bit streams, D1 to D32 are part of the electronic data, output from the central office processor.
(34) In the upstream direction (not shown), the OLT 1200 shall transform optical data, output from the fiber 1160 into electronic data sent to the central office processor. The opposite end of the fiber 1160 is connected to one of the optical dividers 1150.
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(37) The passive optical network 1100 includes an optical line terminal 1200 (OLT), optical transferring devices or optical dividers 1150, the number n of optical network units 1300 (ONUs), and multiple optical fibers 1160, 1162 and 1164, wherein the number n may be a positive integer greater than 2, such as 4, 8 or 12. The optical fiber 1160 connects the optical line terminal 1200 (OLT) and the optical transferring devices or optical dividers 1150 and each of the optical fibers 1162 connects the optical dividers 1150 and a corresponding one of the optical network units 1300 (ONUs). The optical fibers 1164 are used for interconnecting the optical dividers 1150.
(38) Referring to
(39) An OLT 1200 in receiving further comprises two major receiving function: an optical demodulating 1224 and a TDM demuxing 1214.
Embodiment 1
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(41) Referring to
(42) In the upstream direction (not shown), each of the optical network units ONUs 1300 can transform electronic data, output from a corresponding one of the user processors 2100, into optical data sent to one of the optical dividers 1150 through a corresponding one of the optical fibers 1162.
Embodiment 2
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(44) The basic operation principles of “K-muxing in a PON” 1900 have been presented in U.S. Pat. Appl. Pub. No. 20130223840 “Resource Allocation in PON Networks via Wave-front Multiplexing and De-multiplexing,” published on Aug. 29, 2013.
(45)
(46) In the preprocessor 1800, the D1 data stream for a first subscriber is transformed to appear on all 32 outputs carried by all 32 time-slots in the PON 1100 with a unique weighting vector, called wavefront vector 1 or WFV1. So are the remaining 31 down-stream data D2 to D32. More precisely, the 32 substreams (D1 to D32) of data samples after a K-muxing 130 can be expressed as
MD1=w.sub.1,1*D1+w.sub.1,2*D2+ . . . +w.sub.1,32*D32 (1-1)
MD2=w.sub.2,1*D1+w.sub.2,2*D2+ . . . +w.sub.2,32*D32 (1-2)
MD32=w.sub.32,1*D1+w.sub.32,2*D2+ . . . +w.sub.32,32*D32 (1-32)
And equations (1-1) to (1-32) can be written in a matrix form;
[MD]=[W][D] (2)
(47) Furthermore, the column vector [w.sub.1,1, w.sub.2,1, w.sub.3,1, . . . , w.sub.32,1].sup.T is the wavefront vector 1 or WFV1, which “carrys” D1 data stream through the 32 TDM channels through a fiber 1160. So are the remaining 31 wavefront vectors for the 31 remaining down-stream data. We may state that D2 data stream is sent to a destination via a second wavefront WFV2 propagating in a fiber network with 32 channels, and that D32 is riding on WFV32.
(48) We shall note that the output of the TDM mux 1210 will convert a sequential stream of digital samples into a high speed serial bit stream so that the optical modulator 1220 shall convert the electrical bit symbols of 0's and 1's to optical signals with two intensity levels of lasers in fibers.
(49) At destinations, the ONUs will convert the optical signals of TDM muxed digital streams and using K-demuxing to recover the digital streams D1 to D32 accordingly. The recovered D2 data stream is connected to a router 2110 separating data sets for various applications, including those to be sent via a WiFi hub 2130 and those via a picocell hub 2120.
(50) Three post processors 1340 for user 1, user 2 and user 32, respectively are shown in
(51) In another embodiment, a different version of preprocessor 1800 with functions of K-muxing 130 and an OLT 1200 when only 4 of 32 subscribers are participating on the “resource sharing” capability is illustrated in
(52) In a preprocessor 1800 shown in
(53) Details in one deeper layer of a version of the K-muxing 130 in
(54) Each input mapping 132 features configurable functions of 1-to-N TDM demuxing with a constant output clocking rate of 8 Mbps, where N is an integer and 16≥N≥1. Its input rate may vary from 8 Mbps to 128 Mbps.
(55) In addition, a controller 136 is used to configure the 4 sets of input mapping function according to an embedded programmable algorithm. The program may decide bandwidth resources for individual users according to a priority list among the 4 users. As an example, a dynamic priority list reads as follows; (1) 1.sup.st priority for user 1, (2) 2.sup.nd priority for user 17, and (3) 3.sup.rd priority for user 16, and user 32. A resource optimization algorithm allocates upper boundaries of 50% total bandwidth for the 1.sup.st priority user, 25% for the 2.sup.nd priority user, and 12.5% for each remaining two users.
(56) The K-Xing 138 may perform a 16-to-16 Hadamard transform (HT) at a clock rate of 8 Mbps. Let us assume that 8-bit per sample as input samples then the Hadamard transform with 8-bit arithmetic operation will be clocked at 1 million clocks per second. As a result, the 16 outputs must also feature with 8-bit samples with a flow rate of 1 million samples per second. Every 4 of the 16 outputs are aggregated by a device performing 4-to-1 TDM muxing 134 at an output flow rate of 4 million samples per second. In addition, the device shall convert the muxed sample stream in the output to a bit stream at a flow rate of 32 Mbps. Thus, in the 4 bit-stream outputs corresponding to MD1, MD16, MD17, and MD 32, each sample shall feature a weighted sum of corresponding samples in D1, D16, D17, and D32. Similarly, a selected D1 sample shall appear and contribute to the corresponding 4 contiguous output samples in each of all 4 output bit-streams (MD1, MD16, MD17, and MD32). The weighting distribution of the selected D1 sample in the 4 sets of 4 contiguous samples (total 16 samples) shall be one of the 16 wave-front vectors (WFVs) associated with the function of 16-to-16 K-Xing 138 implemented by a 16-to-16 Hadamard transform.
(57) Among the 4 K-muxed data streams, MD1, MD16, MD17, and MD32, a total flow rate of 128 Mbps (32 Mbps*4) is reserved in forward links or a down-stream direction for a PON distribution. The data stream D1 for the first user with a first priority will get an equivalent flow rate of 64 Mbps, and the data stream D17 for the 17.sup.th user with a second priority shall feature a flow rate of 32 Mbps. Similarly, both the data streams D16 for the 16.sup.th user and the data streams D32 for the 32.sup.nd user feature a third priority. Each will get an equivalent flow rate of 16 Mbps.
(58) Alternatively, when we use 64 bit arithmetic operations in the HT, each of the 16 bit stream inputs features a flow rate of 8 Mbps which is considered as a flow of digital samples with a flow rate of 125 K samples per second, or 125 KSps, with 64 bits per sample or 8 bytes per sample. The corresponding K-demuxing 140 not shown in ONUs must feature the same versions of HTs.
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(60) For the 1.sup.st user, the 4-to-1 output switch 1320 will be set by a controller to deliver D1 stream, a right output stream from the 4 outputs of D1, D16, D17, or D32. D1 is flowing at a rate of 64 Mbps. The controlling signals are sent by a central command for the advanced PON. All the calculations have not included the processing overhead.
(61) Details in one more layer of the K-demuxing 140 in
(62) Each output mapping 142 features configurable functions of N-to-1 TDM muxing with a constant input clocking rate of 8 Mbps, where N is an integer and 16≥N≥1. Its output rate may vary from 8 Mbps to 128 Mbps.
(63) In addition, a controller 146 is used to configure functions of the 4 sets of output mapping 142 according to an embedded programmable algorithm which shall be informed by a command center responsible for the dynamic PON configuration. The program may decide bandwidth resources for individual users according to a priority list among the 4 users for both the input mapping 132 in K-muxing 130 and the output mapping 142 in K-muxing 140. As an example, a dynamic priority list reads as follows: (1) 1.sup.st priority for user 1, (2) 2.sup.nd priority for user 17, and (3) 3.sup.rd priority for user 16, and user 32. A resource optimization algorithm allows 50% allocated for the Pt priority user, 25% for the 2.sup.nd priority user, and 12.5% for each of the two remaining users.
(64) The 4 inputs to the K-demuxing 140 are MD1, MD16, MD17, and MD32. Each sample in the 4 inputs shall feature a weighted sum of corresponding samples in D1, D16, D17, and D32 to be recovered. Each input is then connected by a device performing 1-to-4 TDM demuxing 144 at a output flow rate of 1 million samples per second, converting the muxed sample stream in a bit stream format at a flow rate of 32 Mbps to 4 outputs of bit stream each at a flow rate of 8 Mbps, or 1 million sample per second assuming 8 bits per sample There shall be 16 inputs to a device with functions of K-Xing 148, performing a 16-to-16 Hadamard transform (HT) at a clock rate of 1 M operations per second and converting 16 inputs to 16 outputs. Each of the inputs and outputs is flowing at 8 Mbps. We have assumed that 8-bit per sample as input samples then the Hadamard transform with 8-bit arithmetic operation will be clocked at 1 million clocks per second. As a result, the 16 outputs must also feature with 8-bit samples with a flow rate of 1 million samples per second. The outputs shall feature 16 substreams of separated flows of samples of D1, D16, D17, or D32.
(65) Among the 4 K-muxed data streams, MD1, MD16, MD17, and MD32, a total flow rate of 128 Mbps (32 Mbps*4) is reserved in forward links or a down-stream direction for a PON distribution. The data stream D1 for the first user with a first priority will get an equivalent flow rate of 64 Mbps, and the data stream D17 for the 17.sup.th user with a second priority shall feature a flow rate of 32 Mbps. Similarly, both the data streams D16 for the 16.sup.th user and the data streams D32 for the 32.sup.nd user feature a third priority. Each will get an equivalent flow rate of 16 Mbps.
(66) There are 16 total substreams after going through a Hadamard transform concurrently. There shall be 4 output mapping 142 functions in parallel. The first output mapping shall convert n.sub.1 substreams to a D1 stream, where n.sub.1=8 in this example. Similarly, the 2.sup.nd, 3.sup.rd, and 4.sup.th output mapping shall respectively convert n.sub.2, n.sub.3, and n.sub.4 substreams to D16, D17 and D32 data streams. In this example n.sub.2=4, n.sub.3=n.sub.4=2. The 4 sets of output mapping are controlled by a controller 146.
Embodiment 3
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(68) The first smart array shall operate on a cell phone band, connecting multiple cell phones 2236 to the picocell hub 2120 concurrently over a common field of view 2234. The smart array may form concurrent tracking beams with orthogonal beam patterns. For three cell phones 2236, the smart array shall automatically form three concurrent beams. The first beam shall be dynamically optimized following current position of a first cellphone with a beam peak at a first user direction while steering a first null and a second null, respectively, to the directions of the 2.sup.nd and the 3.sup.rd users. As a result, the transmitted signals intended for the first cellphone in forward direction is maximized in the first cellphone direction, and will not reach the second and the third cellphones. In receive, the received signals feature maximized sensitivity in the intended first cellphone direction, and minimized sensitivity (or zero response) at the directions of the second and the third cellphones.
(69) By the same principles, a 2.sup.nd beam shall be dynamically optimized following current position of the 2.sup.nd cellphone with a beam peak at its direction while steering a first null and a second null, respectively, to the directions of the 1.sup.st and the 3.sup.rd cell phones. As a result, the transmitted signals intended for the 2.sup.nd cellphone in forward direction is maximized in its direction, and will not reach the 1.sup.st and the 3.sup.rd cellphones. In receive, the received signals feature maximized sensitivity in the intended 2.sup.nd cellphone direction, and minimized sensitivity (or zero response) at the directions of the first and the third cellphones.
(70) For the concurrent 3.sup.rd beam, it shall be dynamically optimized following current position of the 3.sup.rd cellphone with a beam peak at its direction while steering a first null and a second null, respectively, to the directions of the 1.sup.st and the 2.sup.nd cellphones. As a result, the transmitted signals intended for the 3.sup.rd cellphone in forward direction is maximized in its direction, and will not reach the 1.sup.st and the 2.sup.nd cellphones. In receive, the received signals feature maximized sensitivity in the intended 3.sup.rd cellphone direction, and minimized sensitivity (or zero response) at the directions of the first and the second cellphones.
(71) As a result of the first of the DBF 3120, DBF1, forming three tracking beams with OB patterns, the same frequency slot may be reused by three folds or 3× reused.
(72) 4 array elements 2132 for the WiFi hub 2130 are connected to a device (DBF 2) for DBF functions. A second smart array is form by the 4 elements 2132 and a second one of the DBF 3120 for the WiFi hub 2130. The 2.sup.nd smart antenna shall operate on a WiFi band, connecting to multiple user devices such as notebooks 2136 concurrently over a second common fields of view 2134. The 2.sup.nd smart array may also form concurrent tracking beams with orthogonal beam patterns. For two notebooks, the smart array shall automatically form two concurrent beams. The first beam shall be dynamically optimized following current position of a first notebook with a beam peak at a first user direction while steering a first null, respectively, to the direction of the 2.sup.nd notebook. As a result, the transmitted signals intended for the first notebook in forward direction is maximized in the first notebook direction, and will not reach the second notebook. In receive, the received signals feature maximized sensitivity in the intended first notebook direction, and minimized sensitivity (or zero response) at the direction of the second notebook.
(73) By the same principles, a 2.sup.nd beam shall be dynamically optimized following current position of the 2.sup.nd notebook with a beam peak at its direction while steering a first null to the direction of the 1.sup.st notebook. As a result, the transmitted signals intended for the 2.sup.nd notebook in forward direction is maximized in its direction, and will not reach the 1.sup.st notebook. In receive, the received signals feature maximized sensitivity in the intended 2.sup.nd notebook direction, and minimized sensitivity (or zero response) at the directions of the first and the notebook.
(74)
s.sub.p=[s.sub.p1,s.sub.p2,s.sub.p3] (3-1)
s.sub.w=[s.sub.w1,s.sub.w2] (3-2)
and D2=[s.sub.p,s.sub.w, . . . ] (3-3)
(75) An aggregated signal stream, s.sub.p, comprises three cell phone data streams, s.sub.p1, s.sub.p2, s.sub.p3, where s.sub.p1 for a first cellphone, s.sub.p2 for a 2.sup.nd cellphone, s.sub.p3 for a 3.sup.rd cellphone. These signals are delivered to the cell phones via three shaped beams with OB patterns, which are continuously optimized by the DBF1 tracking all cellphone positions with a first common field of view 2234. They are re-radiated using cell phone bands.
(76) For advanced applications in another embodiment, we may take advantages of 3× frequency reuse potential to concurrently deliver three independent information sets to three cell phones via the 3 shaped beams with OB patterns in a common frequency slot.
(77) Similarly, another aggregated signal stream, s.sub.w, comprises two IP data streams, s.sub.w1, s.sub.w2, where s.sub.w1 for a first of the two notebooks 2136, s.sub.w2 for a 2.sup.nd of the notebooks 2136 within a second common field of view 2134 using same frequency slot in WiFi band. It can achieve a 2× frequency reuse. These signals are delivered to the notebooks 2136 via two shaped beams with OB patterns, which are continuously optimized by the DBF2 tracking all notebooks.
(78) In this configuration, the flow rate in PON 1100 features 1 Gbps throughput total for 32 potential users. The maximum flow rate of the D2 stream for the second user is fixed at ˜32 Mbps.
Embodiment 4
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(80) In short the K-muxing 130 enables the D2 stream being delivered to the user processor 3100 via unused and available bandwidth asset in the PON 1100. The delivery flow rate which may exceed an upper limit set by the time slots by the TDM mux 1210 in the OLT 1200.
(81) The functions of K-muxing 130, in general, may be implemented by software in a hosting processor for better flexibility, by additional hardware for faster processing speed to the hosting processor, or by combinations of the above for compromised performance with flexibility and speed.
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Embodiment 5
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(84) Similarly, the RDBF2 6102B shall feature two inputs and one muxed output, swe, which comprises 4 element signal components to be radiated by the four radiating elements 2132 for a WiFi hub 2130.
(85) There are two input sample streams s.sub.w1 and s.sub.w2 for the DBF in RDBF2 6102A. Each is replicated 4 times and then weighted individually by a beam weight vector (BWV) with 4 components. The 4 outputs feature sums of the two weighted inputs.
E1=w11*s.sub.w1+w12*s.sub.w2 (3a)
E2=w21*s.sub.w1+w22*s.sub.w2 (3b)
E3=w31*s.sub.w1+w32*s.sub.w2 (3c)
E4=w41*s.sub.w1+w42*s.sub.w2 (3d)
(86) The two BWV's for the two beams featuring dynamic tracking capability with OB radiation patterns are represented as follows:
BWV1=[w11,w21,w31,w41].sup.T (4a)
BWV2=[w12,w22,w32,w42].sup.T (4b)
(87) The four element signal streams (E1 to E4) are then FDM muxed into a single output swe.
(88) As indicated in equations (3), each element signals comprises a sum of weighted signals for two notebook signals (s.sub.w1, and s.sub.w2), which will be delivered to the two notebooks 2136, respectively through two tracking beams. These tracking beams are radiated by the four WiFi array elements 2132. The radiations feature dynamic OB beam patterns following the two re-locatable notebooks over a second common field of view 2134. The first FOV 2234 and the second FOV 2134 may have very significant overlaps in coverage.
(89) The two muxed outputs, spe from RDBF1 6102A and swe from RDBF2 6102B, along with others such as s2c depicted in
(90) It is notice that we have used (s1, s2, s3, . . . , s32) in here instead of (D1, D2, D3, D32) in previous figures to indicate the inputs of the K-muxing 130 are signal samples (in waveform domain or after modulation in transmission), and not data samples (in information domain or before modulation in transmission). The K-muxing 130 as a part of preprocessing in the OLT 1200 shall operate in a coherent mode processing samples of signal waveforms or signals in the TDM optical channels.
(91) The PON 1180 shall be operating in a mode of Radio Frequency over Glass (RFoG). The TDM mux 1210 will convert 32 parallel signal sample streams into one muxed sample stream. The mixer 1220 will function as for a heterodyne up-converter to optical frequency band. The laser 1230 will provide an optical carrier.
(92) Differential amplitude variations and phase delays among the optical channels shall be calibrated, and compensated dynamically. Calibration and compensations are part of equalization process which can be done continuously and iteratively optimized. It may also be implemented periodically via matrix inversion optimization. The optimization for dynamic equalization may be implemented in the headend 6100 or user ends as a part of upgraded ONU's 6300. As a result, the equalized multiple channels can be used to transport element signals to be radiated coherently from a first remote digital beam forming 6102A to a set of radiating elements 2232 of an array for transmission of cell phone signals over a common field of view 2234 in a user facility via the user processor 3100.
(93) In the user processor 3100, a demuxing device 2110 shall perform inverse functions of functions of the muxing device 6104 in the headend 6100, separating the signal flows of spe, swe, and s2c. The picocell hub 2120 shall receive a first muxed 4-element signal stream, spe, which is connected to one of the two FDM demux 6510 and being converted to 4 element signal streams. These element signals streams are then sent to the 4 radiating elements 2232 respectively. Concurrently the WiFi hub 2130 shall receive a second muxed 4-element signal stream, swe, which is connected to one of the two FDM demux 6510 for conversion to 4 element signal streams. These element signal streams are then sent to the 4 radiating elements 2132 respectively.
(94) The multiple beam coverage in the first common FOV 2234 for three cellphones 2236 and the second common FOV 2134 for the two notebooks 2136 have been discussed in previous
(95) The K-muxing 130 is operating on signal samples over multiple TDM optical channels. Similarly, the K-demuxing in updated ONUs 6300 shall also feature processing on signal samples among multiple optical TDM channels.
(96) The optimization techniques have been discussed extensively in the reference of U.S. Pat. Appl. Pub. No. 20130223840. Optimization inputs may be replications of some of normal outputs of the K-demuxing 140. In addition, when s1, s16, and s32 for the 3 users are uncorrelated at the headend, it is also possible to use correlations among these three received signals at a user end, detecting “leakages” thus indications of un-equalized propagation channels. These leakages may be used as performance “cost” in optimization schemes which features cost minimization to achieve fine tuning of equalizations of amplitude variations and phase delays among multiple dynamic propagation channels.
Embodiment 6
(97)
(98) The three cellphone data streams (s.sub.p1, s.sub.p2, and s.sub.p3) are sent to a remote digital beam forming processor, RDBF1 6102A, which calculates and implements weighted sums for three concurrent beams to be radiated by the radiating elements associated with the 4 post-processors, 7232-1 to 7232-4, over households of 4 customers.
(99) The associated element signals implemented by the RDBF1 6102A for the 4 radiating elements associated with the 4 post processors 7232-1 to 7232-4 are as followed;
Ep1=w1*s.sub.p1+w12*s.sub.p2+w13*s.sub.p3 (5a)
Ep2=w21*s.sub.p1+w22*s.sub.p2+w23*s.sub.p3 (5b)
Ep3=w31*s.sub.p1+w32*s.sub.p2+w33*s.sub.p3 (5c)
Ep4=w41*s.sub.p1+w42*s.sub.p2+w43*s.sub.p3 (5d)
(100) The three BWV's for the three beams featuring dynamic tracking capability with OB radiation patterns are represented as follows:
BWV1=[w11,w21,w31,w41].sup.T (6a)
BWV2=[w12,w22,w32,w42].sup.T (6b)
BWV3=[w13,w23,w33,w43].sup.T (6c)
(101) Each element signal is sent to a corresponding input of a K-muxing 130 which features N-inputs and N-outputs where N=4. The K-muxing 130 features similar functional blocks as the ones in
(102) A passive fiber network comprises (1) a first fiber segment 1160 connected between an OLT 1200 and a passive divider 1150, (2) second fiber segments connected to a passive divider 1150 to a ONU, and (3) third fiber segments connected between passive dividers 1150.
(103) In the downstream direction, the OLT 1200 continuously transmits optical signal streams. Individual ONUs see their own data through the address labels embedded in the signal. Corresponding post processors 7232-1 to 7232-4 shall recover the element signal streams in RF, which will then be conditioned (amplified and filtered), converted to a desired frequency slot in cellphone band, power amplified, before being sent to respective antenna element for radiation.
(104) These four elements are usually separated by a large distance (>10 in or in terms of 50's or even 500's of cell-band wavelengths) from one another, forming an array by the RDBF1 6120A for a clean connection to a first cellphone 2236-1, that for a second cellphones 2236-2, and that for a third cellphone 2236-3 over a coverage area 7234 in near fields. The coverage area 7234 shall include 4 field-of-views (FOVs) of the four individual elements: a first element FOV 2234-1, a second element FOV 2234-2, a third element FOV 2234-3, and a fourth element FOV 2234-4.
(105) Each of the 4 post processors 7232 comprises an updated ONU 6300, a picocell hub 2120, and a cell antenna 2232. These are identical to the ones shown in
(106) A first dynamically shaped beam is for the 1st cellphone 2236-1 and shall feature a tracking beam peak at the location of the 1.sup.st cellphone with two tracking nulls at the locations of the 2.sup.nd and the 3.sup.rd cellphones. Similarly, a 2.sup.nd dynamically shaped beam shall feature a tracking beam peak at the location of the 2.sup.nd cellphone 2236-2 with two tracking nulls at the locations of the 1.sup.st and the 3.sup.rd cellphones 2236-1 and 2236-3. In addition, a 3.sup.rd dynamically shaped beam shall feature a tracking beam peak at the location of the 3.sup.rd cellphone 2236-3 with two tracking nulls at the locations of the 1.sup.st and the 2.sup.nd cellphones 2236-1 and 2236-2. The three dynamic shaped beams operated in a same frequency slot, featuring 3× frequency reuse, shall have very little mutual interferences.
(107) In the upstream direction (not shown), each ONU burst transmits for an assigned time-slot (multiplexed in the time domain). In this way, the OLT is receiving signals from only one ONU or ONT at any point in time. However, with a K-demuxing 140, which features 4 inputs and 4 outputs, in place for the headend 6100, the OLT shall be receiving signals from only one ONU at most point in time, but shall be capturing 4 muxed signals from 4 participating ONUs at assigned 4 time slots, assuming the lasers for the 4 ONUs emitting in an identical optical wavelength.
(108) When the lasers for the 4 ONUs emitting in different optical wavelength, there shall have multiple optical spectrum lines in assigned received time slots. Each modulated optical line in the spectrum shall be associated to a specific ONU. Additional processing using advanced filtering techniques are required to separate the modulating RF signals for individual optical wavelength. Thus, RF signal streams from individual ONUs are captured separately for further processing.
Multibeam RDBF Ground Terminals for Satellite Constellations in Non-Geostationary Orbits (NGSO)
(109) Since 2015, there have been many proposals for satellite constellations filed with the Federal Communications Commission (FCC) in C, Ku, Ka, V bands, and other bands in non-geostationary orbit (NGSO) for IP connectivity including proposed systems by companies such as SpaceX, Oneweb, Boeing, and others. The proposed constellations range from less than 1000 to more than 5000 satellites, and many of them will be orbiting at around 1200 Km in altitude, providing broadband “last mile connectivity” or broadband accessing to subscribers. A subscriber on ground shall gain access of wide bandwidth or high data rate via multiple satellites concurrently. With a simultaneous view of 40 or more satellites, a subscriber will access a set of the satellites in a field-of-view (FOV) of its multi-beam terminal. The terminal shall feature multiple beams concurrently in a common frequency slot, and may also feature multiple sets of the multiple concurrent beams at various frequency slots. The multiple beams for communications services, at least two concurrent receiving (Rx) beams, are referred to as service beams. DBF are very cost effective in forming multiple Rx beams. For instance, additional Rx beams may be formed for probing and diagnostic purposes. Diagnostic beams are not for receiving information data and may feature fast hopping beams, as an example, to detect radiated power levels from various pre-determined beam positions as in autonomous tracking loops initiated by a beam controller at the terminal.
(110) The techniques using low cost passive optical network (PON) for remote digital beam forming (RDBF) networks may also be utilized in implementing advanced ground terminals for communicating to NGSO satellites. The K-muxing overlaid over a PON is similar to the ones previously described ire
(111)
(112) The details of an OLT 1200 are shown in
(113)
(114) In general, an array antenna with Ne elements can support Nb independent beams concurrently, where Ne and Nb are positive integers and Ne≥Nb. When the spacing for adjacent elements of the array antenna is larger than or equal to a half wavelength of the radiating/receiving RF frequency, the array antenna with Ne elements can form a set of Nb beams with orthogonal beam (OB) patterns, for which the peak of a first OB beam is pointed at a first direction where a null of each of the other Ne-1 OB beams will be located, and the first OB beam will also feature Ne-1 nulls at various Ne-1 directions where peaks of the other Ne-1 OB beams are pointed to. For applications of RDBF ground terminals for NGSO satellite communications, it will be very cost effective to use arrays with no less than 10 Rx/Tx elements.
(115) Digital beam forming (DBF) networks in general are very cost-effective in forming multiple Rx beams. Therefore, via the Rx RDBF 8102 network in the ground terminal 8000, the array 8232 shall form additional beams for probing or diagnostic purposes providing information or measured intelligence for a beam controller 8140 which shall determine what the available satellites are, which directions these tracking beams shall be pointed to in the next time slots, what to do to avoid high mutual interferences among these beams, and so on. The beam controller 8140 will take these results into consideration in deciding and calculating beam weighting vectors (BWVs) for the 7 tracking beams for a next update or for next few updates.
(116) We may use a technique generating multiple (N.sub.b) beam positions surrounding each of tracked moving satellites within the field of view (FOV) of the ground terminal 8000. The FOV may feature an entire angular region of 20 degrees above horizon. We may choose N.sub.b=6. For each tracked satellite, a diagnostic beam will hop over the satellite current position and N.sub.b=6 additional surrounding beam positions. To support 7 tracked satellites, diagnostic beams must visit 49 different beam positions multiple times within a tracking cycle time, say, Tf=1 second. Assuming a 2-millisecond (ms) dwell time on each position measuring emitted RF signal power levels with signatures or identifications by satellites, it is possible to command a diagnostic beam by the beam controller to visit all 49 possible beam positions 10 times. The emitted signal signatures or identifications may simply be the radiated frequency, modulation, and/or other features. With two agile diagnostic beams, it becomes possible to visit these beam positions 20 times in one-second tracking cycle time. Additional diagnostic beams may probe beam positions at periphery of the field of view of the ground terminal 8000 for newly arrived satellites.
(117) In other embodiments, the beam positions for diagnostic beams may be designed and planned by the beam controller according to predicted satellite tracks. Each satellite track in the FOV of the ground terminal from an entrance to an exit will be covered by multiple (Mb) overlapped beam positions, where Mb ranges from 10 to 20. There may be a total of 100 potential beam positions to be covered by 4 diagnostic beams. They can provide 40 independent measurements on each beam position within one-second tracking cycle time.
(118) The optical fibers 1160 are connected to the RF-to-optical drivers of the OLT 1200 in the outdoor unit 8200 and optical-to-RF converters of an ONU 1300 in the indoor unit 8100. The indoor unit 8100 comprises a post processor 140 with K-demuxing transform, and Rx Remote digital beam forming (RDBF) 8102 networks followed by a bank of RF demodulators 8104. It further comprises a set of adaptive equalizers 140A controlled by an iterative optimization loop 8106.
(119) To implement the fiber connection cost-effectively we shall take advantage of the optical fiber connections via a PON standard, instead of using special designs or customized optical connections. Conventional PON systems, such as 10G EPON, are TDM standards. The standards for even broader bandwidth may include optical fiber connections comprising wavelength division multiplexing (WDM) standards.
(120) An Rx RDBF ground terminal 8000 may be implemented on a mobile platform, such as a passenger car, a bus, a train, and others. The outdoor unit 8200 is located on the roof of a mobile platform, and while the input unit 8100 is located in the cabin of the mobile platform. For a stationary RGBF terminal, the outdoor unit 8200 is located on premises of a home, while the indoor unit 8100 is located inside of a set-top-box (SIB) placed in the home. The RDBF 8102 network in the indoor unit may form dynamic beams with orthogonal beam patterns tracking various NGSO satellites 8300 within the field of view of the ground terminal. The remote digital beam-forming network may form multiple diagnostic beams to continuously probe identities of the satellites and where the satellites are moving to, within a field-of-view of the receiving terminal.
(121) For an Rx RDBF terminal, the K-muxing transform in the pre-processor 130 in the outdoor unit may be a Hadamard transform matrix, a Fourier transform matrix or a combination of both. It may also be another N-to-N orthogonal matrix, or a N-to-N full-rank matrix, where N is an integer greater than 1. Similarly, the corresponding K-demuxing transform in the post-processor 140 in the indoor unit 8100 shall be a Hadamard transform matrix, a Fourier transform matrix, or a combination of both. The K-demuxing transform in the post-processor 140 in the indoor unit shall be the inverse of the chosen N-to-N orthogonal matrix, or the chosen N-to-N full-rank matrix for the K-muxing in the outdoor unit 8200. The inverse of an orthogonal matrix is its transpose and therefore another orthogonal matrix.
(122) Similarly, a transmitting (Tx) RDBF ground terminal for communications systems via NGSO satellites 8300 can be implemented in the same indoor unit 8100 and the same outdoor unit 8200 that are interconnected via the same optical fibers 1160. These blocks are not depicted in
RDBF Basestations for Cellular Communications Via PON
(123) In another embodiment, the multichannel PON connectivity is used for 5G wireless mobile services in MIMO basestations. As shown in
(124) Many MIMO wireless configurations take advantage of multiple propagation paths due to signal scattering and reflections to enable multiple folds of frequency reuses between a transmitter at a source and a receiver at a destination via multiple elements in transmit at the source and multiple elements in receiving (Rs) at the destination. A Tx MIMO processor organizes the multiple Tx elements at the source, and an Rx MIMO processor organizes the Rx elements. Scattering and reflections are highly dependent on MIMO operational environments. The parameters of propagation effects are referred to as channel state information (CSI) which is continuously and dynamically measured pair-by-pair between Tx elements at a source and Rx elements at a destination. Many Tx MIMO processors for multiple element arrays usually generate wireless connection with high connectivity via a set of linear combinations of array elements toward some of receiving elements at a destination, while doing discrimination against other receiving elements.
(125) Unlike conventional beam forming which are directional-based, the MIMO connection and discrimination functions by the MIMO processor 9102 are element-index based. For instance in a MIMO communication with 4 Tx array elements at a source and 6 Rx elements in a destination, a dynamically measured. CSI parameter, h32, is referred to as a first transfer function which is a quantitatively measured amount of a propagation phase delay and associated relative attenuation from a second Tx element of the 4-element Tx array to a third Rx element of the 6-element Rx array, while another CSI parameter, a second transfer function h63, shall indicate the amount of a propagation phase delay and associated relative attenuation from a third Tx element of the 4 element. Tx array to a sixth (6th) Rx element of the Rx array. It is noted that the CSI parameters are specified as functions of indexes of Tx elements and Rx elements. The performances of a MIMO array antenna and its MIMO processing feature element-indexed descriptions.
(126) On the other hand, in conventional beam forming performance, the connectivity of an array antenna is quantified by an antenna gain at a beam peak while the discriminations are measured in null depth in dB relative to its beam peak at specified directions. For instance, we may specify performance of a 15-element linear array antenna for a shaped spot beam as the following; (1) a beam peak of 20 dB at −2° away from the array boresight, and (2) −50 dB nulls at ±3° and ±5° away from the beam peak. It is noted that most performances in conventional beam forming processors are referred to as functions of angles or directions. The performances of an array antenna and its conventional beam forming feature direction-based descriptions.
(127) Many MIMO arrays feature only digital MIMO processor without beam forming processors at all. However, U.S. Patent Application Publication Number 20140161018 presents MIMO configurations with both MIMO processors and digital beam forming (DBF) networks. In a multi-user MIMO, the serving signals for transmission to user equipment (UE) in spoke-and-hub configurations from a hub will utilize composited transfer functions (CTF) selected and characterized based on channel state information (CSI), which comprises responses from probing signal sequences for multipath dominated propagation channels in accordance with a dynamic distribution of users 2236. A composited transfer function (CTF) is a point-to-multipoint transfer function and is constructed by combining multiple point-to-point transfer functions. The combining and shaping are via beam forming optimizations in transmitters to be “user element dependent” with enhanced responses to a selected user array element and suppressed responses to other user elements. The composited transfer functions (CIEs) are constrained by desired performance criteria, which are not specified as functions of directions in angles, but as functions of the indexes of user array elements, which are the identifications in UE. These are referred as user indexed constraints. In this case, the MIMO processing and DBE processing are separately implemented by two different devices or software blocks.
(128) The techniques using low cost passive optical network (PON) for remote digital beam forming (RDBF) networks may also be utilized in basestations of wireless cell phone systems, including 5G MIMO basestations. The K-muxing overlaid over a PON is similar to the ones previously described ire
(129)
(130) The remote MIMO transmitting (Tx) processor 9102 in the indoor processing facility 9100 of the MIMO basestation 9000 will continuously measure the channel status information (CSI) by sending probing signals to antenna elements in destinations. The MIMO Tx processor 9102 will also receive responded probing signals from antenna elements in the destination. The indoor processing facility 9100 may have a dedicated digital MIMO processing assembly 9102A to measure various dynamic transfer functions for CSI, and to enable frequency reuses by generating favorable coherent gains to some receiving elements and discriminations against other using elements. These elements in both Tx and Rx ends are not identified through relative directions in their dynamic geometries but by unique indexes associated with the elements. The connection and discrimination functions are made in the MIMO processing assembly 9102A in terms of the elements identified via indexes. It is an optimization processing in a space with indexes of array elements; referred to as an element-indexed space. It takes advantages of a multi-path rich propagation environment 9300 creating multiple concurrent channels from the RF tower to a destination. The remote MIMO Tx processor 9102 may comprise remote digital beam forming (RDBF) networks 6102A, remote composited transfer function (CTF) networks in a digital MIMO processing assembly 9102A for the purposes of achieving point-to-multipoint performance constraints in an element-indexed space.
(131) The indoor processing facility 9100 further comprises a set of adaptive equalizers 140A following the K-muxing 130 transform. The equalizers 140A controlled by an optimization loop 9106 will perform pre-distortion compensations for multichannel propagation signals in the optical fibers which support optical communications via a passive optical network (PON) standard, a wavelength division multiplexing (WDM-PON) standard, in one of the RFoG network standardized options, or others.
(132) The RDBF 6102 network in the remote MIMO Tx processor can be configured to form multiple spot beams pointing to various directions within a field of view of the transmit elements on the outdoor RF tower. It operates to form multiple shaped beams with partial overlapped covered areas within the field of view of the transmit elements on the outdoor RF tower.
(133) The K-muxing 130 transform in the preprocessor for the indoor processing facility 9100 comprises a Hadamard transform matrix, a Fourier transform matrix, a N-to-N orthogonal matrix, a N-to-N full-rank matrix, where N is an integer greater than 1, or a combination of all the above. Correspondingly, the K-demuxing transform in the post-processor 140 in the outdoor RF tower 9200 of the MIMO basestation 9000 in a transmitting mode comprises a Hadamard transform matrix, a Fourier transform matrix, a N-to-N orthogonal matrix, a N-to-N full-rank matrix, where N is an integer greater than 1, or a combination of all the above.
(134) In a receiving (Rx) mode for a cellular communications system, a MIMO basestation will perform functions that are reverse of the transmitting mode functions. The MIMO station in an Rx mode comprises an outdoor RF tower including radiating/receiving elements and a remote indoor processing facility, interconnected via optical fibers. The outdoor RE tower comprises RF array antenna with multiple Rx elements, low-noise amplifiers (LNAs), a pre-processor with K-maxing transforms, and RF-to-optical drivers for optical modulating functions. The optical fibers connect the RF-to-optical drivers on the outdoor RF tower to optical-to-RF converters in the indoor processing facility. The indoor processing facility comprises the optical-to-RE converters for optical de-modulating functions, a postprocessor with K-demuxing transforms followed by a MIMO receiving (Rx) processor, and a bank of RF de-modulators.
(135) The RF array antenna may operate at current mobile cellular communications frequency bands; such as 1700/2100 MHz, 2600 MHz, 850 MHz, 1900 MHz and others in U.S. and Canada. Planned 5G cellular systems may operate below 6 GHz and also at selected millimeter frequency bands. The RF array for MIMO may operate in a WiFi frequency such as 2.4 GHz, 3.6 (3 Hz, 4.9 GHz, 5 GHz 5.9 (3 Hz and others.
(136) In most applications for continuously measuring the channel status information (CSI), the basestation will initiate procedures by sending probing signals via the Tx ports of various antenna elements at the basestation. The MIMO Rx processor in the indoor processing facility of the MIMO basestation will collect the responses of the probing signals sent by various array elements from different users. The responses usually are unique acknowledgement signals to various antenna elements of users. In other applications the CSI measurement may be initiated by users. The MIMO Rx processor in the indoor facility of the MIMO basestation shall respond to the probing signals sent by various users with unique acknowledgement or signature signals.
(137) The MIMO Rx processor in the indoor processing facility may comprise RDBF networks which can be configured to form multiple spot beams pointing to various directions within a field of view of the Rx elements on the outdoor RF tower. It operates to form multiple shaped beams with partial overlapped covered areas within the field of view of the Rx elements on the outdoor RF tower.
(138) The indoor processing facility further comprises a set of adaptive equalizers for distortion compensation for multichannel propagation signals in the optical fibers which support optical communications via a passive optical network (PON) standard, a wavelength division multiplexing (WDM-PON) standard, in one of the RFoG network standardized options, or others.
(139) The K-muxing transform in the preprocessor for the outdoor RF tower facility comprises a Hadamard transform matrix, a Fourier transform matrix, a N-to-N orthogonal matrix, a N-to-N full-rank matrix, where N is an integer greater than 1, or a combination of all the above. Correspondingly, the K-demuxing transform in the post-processor in the indoor processing facility of the MIMO basestation in a Rx mode comprises a Hadamard transform matrix, a Fourier transform matrix, a N-to-N orthogonal matrix, a N-to-N full-rank matrix, where N is an integer greater than 1, or a combination of all the above.