WIRELESS MIMO TRANSCEIVER SYSTEM IN HIGH SPEED MOBILITY AND METHOD THEREOF
20220311486 · 2022-09-29
Inventors
- Shashank TIWARI (Pratapgarh, IN)
- Suvra Sekhar DAS (Kharagpur, IN)
- Subhas Chandra Mondal (Bangalore, IN)
- Parag AGGARWAL (Bengaluru, IN)
Cpc classification
H04L27/2639
ELECTRICITY
International classification
Abstract
The disclosure relates to method and system for providing a MIMO transceiver in high speed mobility. The method includes dividing, by the wireless MIMO transmitter, transmission data into a plurality of transmit chains corresponding to an antenna. The method further includes generating for the plurality of transmit chains, a Circularly Pulse Shaped Orthogonal Time Frequency Space (CPS-OTFS) time frequency signal based on a first primary parameter. Value of the first primary parameter is determined based on a first predefined algorithm. The method further includes converting for the plurality of transmit chains, the CPS-OTFS time frequency signal to a CPS-OTFS time domain signal based on at least one of a plurality of secondary parameters. A first plurality of N-point Inverse Fast Fourier Transform (IFFT) are employed on the CPS-OTFS time frequency signal. The first plurality corresponds to the number of sub-carriers and N corresponds to a set of time symbols.
Claims
1. A wireless Multiple Input Multiple Output (MIMO) transmitter comprising: a plurality of transmit antennas; a memory storing a plurality of primary parameters and a plurality of secondary parameters; a controller communicatively coupled to each of the plurality of transmit antennas and the memory, wherein the controller is configured to: divide transmission data into a plurality of transmit chains corresponding to each of the plurality of antennas; generate, for each of the plurality of transmit chains, a Circularly Pulse Shaped Orthogonal Time Frequency Space (CPS-OTFS) time frequency signal based on a first primary parameter from the plurality of primary parameters, wherein value of the first primary parameter is determined based on a first predefined algorithm; and convert, for each the plurality of transmit chains, the CPS-OTFS time frequency signal to a CPS-OTFS time domain signal based on at least one of the plurality of secondary parameters, wherein a first plurality of N-point Inverse Fast Fourier Transform (IFFT) are employed on the CPS-OTFS time frequency signal, and wherein the first plurality corresponds to the number of sub-carriers and N corresponds to a set of time symbols.
2. The wireless MIMO transmitter of claim 1, wherein the controller is further configured to insert a Cyclic Prefix (CP) to the CPS-OTFS time domain signal based on one of the plurality of secondary parameters.
3. The wireless MIMO transmitter of claim 2, wherein the controller is further configured to transmit, via an associated transmit antenna from the plurality of transmit antennas, the CPS-OTFS time domain signal in response to inserting the CP.
4. The wireless MIMO transmitter of claim 1, wherein the controller is further configured to convert each of the set of time symbols within the CPS-OTFS time frequency signal into time domain transmission signal CPS-OTFS time domain signal using the first plurality of N-point Inverse Fast Fourier Transform (IFFT).
5. The wireless MIMO transmitter of claim 1, wherein the plurality of primary parameters comprise a Pulse Shaped Time-Frequency Coefficient (PSTFC), a Signal Correction Coefficient (SCC), and 2-Dimensional Quasi-Banded Channel Matrix (2D-QBCM), and wherein the first primary parameter is the PSTFC.
6. The wireless MIMO transmitter of claim 1, wherein the plurality of secondary parameters comprises Prefix and Postfix Configuration Parameters (PPCP), coding and decoding related parameters, modulation and demodulation related configuration parameters, and Transmission Parameters (TP) comprising at least one of number of time symbols, transmission duration, number of sub-carriers, circulant delay value, and Doppler value.
7. A wireless Multiple Input Multiple Output (MIMO) receiver comprising: a plurality of receiver antennas; a memory storing a plurality of primary parameters and a plurality of secondary parameters; a controller communicatively coupled to each of the plurality of receiver antennas and the memory, wherein the controller is configured to: transform, for each of a plurality of receive chains, a conditioned Circularly Pulse Shaped Orthogonal Time Frequency Space (CPS-OTFS) time domain signal to a CPS-OTFS time domain channel equalized signal based on a second primary parameter from the plurality of primary parameters, wherein the second primary parameter is determined based on a second predefined algorithm; convert, for each of the plurality of receive chains, the CPS-OTFS time domain channel equalized signal to a CPS-OTFS time frequency channel equalized signal by employing a first plurality of N-point Fast Fourier Transform (FFT) on CPS-OTFS time domain channel equalized signal, wherein the first plurality corresponds to the number of sub-carriers and N corresponds to a set of time symbols; and estimate, for each of the plurality of receive chains, a data signal from the CPS-OTFS time frequency channel equalized signal based on a first secondary parameter of the plurality of secondary parameters, wherein the data signal corresponds to the plurality of receiver antennas.
8. The wireless MIMO receiver of claim 7, wherein the controller is further configured to: sequence, for each of the plurality of receive chains, the data signal to generate a sequenced data based on a second secondary parameter of the plurality of secondary parameters; decode, for each of the plurality of receive chains, the sequenced data to retrieve a transmitted data based on a third secondary parameter of the plurality of secondary parameters; and provide, for each of the plurality of receive chains, the retrieved transmitted data.
9. The wireless MIMO receiver of claim 8, wherein the plurality of secondary parameters comprises Prefix and Postfix Configuration Parameters (PPCP), coding and decoding related parameters, sequencing related configuration parameters, modulation and demodulation related configuration parameters, and Transmission Parameters (TP) comprising at least one of number of time symbols, transmission duration, the number of sub-carriers, circulant delay value, channel attenuation factor, and doppler value, and wherein the first secondary parameter corresponds to the demodulation related configuration parameters, the second secondary parameter corresponds to the sequencing related configuration parameters, and the third secondary parameter corresponds to the decoding related parameters.
10. The wireless MIMO receiver of claim 7, wherein the controller is further configured to receive, via an associated receiver antenna from the plurality of receiver antennas, a CPS-OTFS time domain signal.
11. The wireless MIMO receiver of claim 10, wherein the controller is further configured to: remove a Cyclic Prefix (CP) attached to the CPS-OTFS time domain signal to retrieve the CPS-OTFS time domain signal; sample the CPS-OTFS time domain signal based on at least one of the plurality of secondary parameters; and generate the conditioned CPS-OTFS time domain signal in response to sampling the CPS-OTFS time domain signal.
12. The wireless MIMO receiver of claim 7, wherein the plurality of primary parameters comprise a Pulse Shaped Time-Frequency Coefficient (PSTFC), a Signal Correction Coefficient (SCC), and 2-Dimensional Quasi-Banded Channel Matrix (2D-QBCM), and wherein the second primary parameter is the 2D-QBCM.
13. The wireless MIMO receiver of claim 12, wherein to transform the conditioned Circularly Pulse Shaped Orthogonal Time Frequency Space (CPS-OTFS) time domain signal to a CPS-OTFS time domain channel equalized signal, the controller is further configured to: transform the conditioned CPS-OTFS time domain signal into an intermediate state signal using backward substitution of lower triangular factorized 2D-QBCM; and transform the intermediate state signal further using forward substitution of upper triangular factorized 2D-QBCM.
14. A transmission method through a wireless Multiple Input Multiple Output (MIMO) transmitter, the method comprising: dividing, by the wireless MIMO transmitter, transmission data into a plurality of transmit chains corresponding to each of a plurality of antennas; generating, by the wireless MIMO transmitter, for each of the plurality of transmit chains, a Circularly Pulse Shaped Orthogonal Time Frequency Space (CPS-OTFS) time frequency signal based on a first primary parameter from a plurality of primary parameters, wherein value of the first primary parameter is determined based on a first predefined algorithm; and converting, by the wireless MIMO transmitter, for each the plurality of transmit chains, the CPS-OTFS time frequency signal to a CPS-OTFS time domain signal based on at least one of a plurality of secondary parameters, wherein a first plurality of N-point Inverse Fast Fourier Transform (IFFT) are employed on the CPS-OTFS time frequency signal, and wherein the first plurality corresponds to the number of sub-carriers and N corresponds to a set of time symbols.
15. The method of claim 14, further comprising inserting a Cyclic Prefix (CP) to the CPS-OTFS time domain signal based on one of the plurality of secondary parameters.
16. The method of claim 15, further comprising transmitting, via an associated transmit antenna from the plurality of transmit antennas, the CPS-OTFS time domain signal in response to inserting the CP.
17. The method of claim 14, further comprising converting each of the set of time symbols within the CPS-OTFS time frequency signal into time domain transmission signal CPS-OTFS time domain signal using the first plurality of N-point Inverse Fast Fourier Transform (IFFT).
18. The method of claim 14, wherein the plurality of primary parameters comprises a Pulse Shaped Time-Frequency Coefficient (PSTFC), a Signal Correction Coefficient (SCC), and 2-Dimensional Quasi-Banded Channel Matrix (2D-QBCM), and wherein the first primary parameter is the PSTFC.
19. The method of claim 14, wherein the plurality of secondary parameters comprises Prefix and Postfix Configuration Parameters (PPCP), coding and decoding related parameters, modulation and demodulation related configuration parameters, and Transmission Parameters (TP) comprising at least one of number of time symbols, transmission duration, number of sub-carriers, circulant delay value, and Doppler value.
20. A transmission method through a wireless Multiple Input Multiple Output (MIMO) receiver, the method comprising: transforming, by the wireless MIMO receiver, for each of a plurality of receive chains, a conditioned Circularly Pulse Shaped Orthogonal Time Frequency Space (CPS-OTFS) time domain signal to a CPS-OTFS time domain channel equalized signal based on a second primary parameter from a plurality of primary parameters, wherein a second primary parameter is determined based on a second predefined algorithm; converting, by the wireless MIMO receiver, for each of the plurality of receive chains, the CPS-OTFS time domain channel equalized signal to a CPS-OTFS time frequency channel equalized signal by employing a first plurality of N-point Fast Fourier Transform (FFT) on CPS-OTFS time domain channel equalized signal, wherein the first plurality corresponds to a number of sub-carriers and N corresponds to a set of time symbols; and estimating, by the wireless MIMO receiver, for each of the plurality of receive chains, a data signal from the CPS-OTFS time frequency channel equalized signal based on a first secondary parameter of the plurality of secondary parameters, wherein the data signal corresponds to the plurality of receiver antennas.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The accompanying drawings, which are incorporated in and constitute a part of this disclosure, illustrate exemplary embodiments and, together with the description, serve to explain the disclosed principles.
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DETAILED DESCRIPTION
[0022] Exemplary embodiments are described with reference to the accompanying drawings. Wherever convenient, the same reference numbers are used throughout the drawings to refer to the same or like parts. While examples and features of disclosed principles are described herein, modifications, adaptations, and other implementations are possible without departing from the spirit and scope of the disclosed embodiments. It is intended that the following detailed description be considered as exemplary only, with the true scope and spirit being indicated by the following claims. Additional illustrative embodiments are listed below.
[0023] Referring now to
[0024] As is illustrated, the MIMO network may comprise a MIMO transceiver 102 connected to multiple eNodeBs i.e., eNodeB104-1, eNodeB 104-2, eNodeB 104-3, and eNodeB 104-N. Each of the multiple eNodeBs may be connected to multiple UEs, i.e., eNodeB104-1 may be connected to UE104-11, UE104-12, . . . UE104-1N, eNodeB 104-2 may be connected to UE104-21, UE104-22, . . . UE10-2N, eNodeB 104-3 may be connected to UE104-31, UE104-32, . . . UE104-3N, and eNodeB 104-N may be connected to UE104-N1, UE104-N2, . . . UE104-NN. The UEs may be such as a laptop, a mobile computing device, a tablet, a phablet, a Personal Digital Assistant (PDA), or an IoT system and so forth.
[0025] In an embodiment, the wireless MIMO transceiver 102 may operate either as a wireless MIMO transmitter or a wireless MIMO receiver. During the MIMO transceiver 102 operating in a transmitter mode, the wireless MIMO transmitter may divide transmission data into a plurality of transmit chains corresponding to each of a plurality of antennas. The wireless MIMO transmitter may generate, for each of the plurality of transmit chains, a Circularly Pulse Shaped Orthogonal Time Frequency Space (CPS-OTFS) time frequency signal based on a first primary parameter from a plurality of primary parameters. Value of the first primary parameter may be determined based on a first predefined algorithm. The plurality of primary parameters may include a Pulse Shaped Time-Frequency Coefficient (PSTFC), a Signal Correction Coefficient (SCC), and 2-Dimensional Quasi-Banded Channel Matrix (2D-QBCM). The first primary parameter may be the PSTFC.
[0026] Further, the wireless MIMO transmitter may convert, for each the plurality of transmit chains, the CPS-OTFS time frequency signal to a CPS-OTFS time domain signal based on at least one of a plurality of secondary parameters. The plurality of secondary parameters may include Prefix and Postfix Configuration Parameters (PPCP), coding and decoding related parameters, modulation and demodulation related configuration parameters, and Transmission Parameters (TP) comprising at least one of number of time symbols, transmission duration, number of sub-carriers, circulant delay value, and Doppler value.
[0027] A first plurality of N-point Inverse Fast Fourier Transform (IFFT) may be employed on the CPS-OTFS time frequency signal. The first plurality may correspond to the number of sub-carriers and N may correspond to a set of time symbols.
[0028] The wireless MIMO transmitter may insert a Cyclic Prefix (CP) to the CPS-OTFS time domain signal based on one of the plurality of secondary parameters and may transmit, via an associated transmit antenna from the plurality of transmit antennas, the CPS-OTFS time domain signal in response to inserting the CP.
[0029] The wireless MIMO transmitter may convert each of the set of time symbols within the CPS-OTFS time frequency signal into a time domain transmission signal CPS-OTFS time domain signal using the first plurality of N-point Inverse Fast Fourier Transform (IFFT).
[0030] In an embodiment, during the MIMO transceiver 102 operating in a receiver mode, the wireless MIMO receiver may transform, for each of a plurality of receive chains, a conditioned Circularly Pulse Shaped Orthogonal Time Frequency Space (CPS-OTFS) time domain signal to a CPS-OTFS time domain channel equalized signal based on a second primary parameter from a plurality of primary parameters. A second primary parameter is determined based on a second predefined algorithm.
[0031] The MIMO receiver may receive, via an associated receiver antenna from the plurality of receiver antennas, a CPS-OTFS time domain signal. The MIMO receiver may convert, for each of the plurality of receive chains, the CPS-OTFS time domain channel equalized signal to a CPS-OTFS time frequency channel equalized signal by employing a first plurality of N-point Fast Fourier Transform (FFT) on CPS-OTFS time domain channel equalized signal. The first plurality may correspond to a number of sub-carriers and N may correspond to a set of time symbols. The wireless MIMO receiver may estimate, for each of the plurality of receive chains, a data signal from the CPS-OTFS time frequency channel equalized signal based on a first secondary parameter of the plurality of secondary parameters. The data signal may correspond to the plurality of receiver antennas.
[0032] The wireless MIMO receiver may sequence, for each of the plurality of receive chains, the data signal to generate a sequenced data based on a second secondary parameter of the plurality of secondary parameters. The wireless MIMO receiver may decode, for each of the plurality of receive chains, the sequenced data to retrieve a transmitted data based on a third secondary parameter of the plurality of secondary parameters, and may provide, for each of the plurality of receive chains, the retrieved transmitted data. The plurality of secondary parameters may include Prefix and Postfix Configuration Parameters (PPCP), coding and decoding related parameters, sequencing related configuration parameters, modulation and demodulation related configuration parameters, and Transmission Parameters (TP) comprising at least one of number of time symbols, transmission duration, the number of sub-carriers, circulant delay value, channel attenuation factor, and doppler value. The first secondary parameter may correspond to the demodulation related configuration parameters, the second secondary parameter may correspond to the sequencing related configuration parameters, and the third secondary parameter may correspond to the decoding related parameters. The plurality of primary parameters may include a Pulse Shaped Time-Frequency Coefficient (PSTFC), a Signal Correction Coefficient (SCC), and 2-Dimensional Quasi-Banded Channel Matrix (2D-QBCM). The second primary parameter may be the 2D-QBCM.
[0033] The wireless MIMO receiver may remove a Cyclic Prefix (CP) attached to the CPS-OTFS time domain signal to retrieve the CPS-OTFS time domain signal. The wireless MIMO receiver may sample the CPS-OTFS time domain signal based on at least one of the plurality of secondary parameters, and may generate the conditioned CPS-OTFS time domain signal in response to sampling the CPS-OTFS time domain signal. The wireless MIMO receiver may transform the conditioned CPS-OTFS time domain signal to a CPS-OTFS time domain channel equalized signal and may include transforming the conditioned CPS-OTFS time domain signal into an intermediate state signal using backward substitution of lower triangular factorized 2D-QBCM, and transforming the intermediate state signal further using forward substitution of upper triangular factorized 2D-QBCM.
[0034] Referring now to
[0035] Upon booting of the wireless MIMO transceiver system 100, an expected mode of operation of the wireless MIMO transceiver 200 may be determined. The MTCM 212 may determine the mode of operation either by retrieving an operating mode of the wireless MIMO transceiver 200 during last power-cycle stored in persistent memory of the wireless MIMO transceiver 200 or through a control signal. The determined mode of operation of the wireless MIMO transceiver 200 may be any of a transmitter mode (T-mode) or a receiver mode (R-Mode). The MTCM 212 may set the wireless MIMO transceiver 200 in the determined mode of operation. Further, the MTCM 212 may activate corresponding modules of the wireless MIMO transceiver 200 based on the determined mode of operation. If the determined operating mode is the T-mode, the MTCM 212 may activate the PCMU 214, the WG.sub.X module 204, the WT.sub.X module 206, and the WCM.sub.X module 208. Additionally, the MTCM 212 may store multiple primary and secondary parameters. The multiple primary parameters may include a Pulse Shaped Time-Frequency Coefficient (PSTFC), a Signal Correction Coefficient (SCC), and 2-Dimensional Quasi-Banded Channel Matrix (2D-QBCM). The multiple secondary parameters may include Prefix and Postfix Configuration Parameters (PPCP), coding and decoding related parameters, modulation and demodulation related configuration parameters, and Transmission Parameters (TP) including at least one of number of time symbols (N), transmission duration (T), number of sub-carriers (M), circulant delay value, channel attenuation factor, and Doppler value. A corresponding primary and secondary parameter may be used by wireless MIMO transceiver 200 based on the determined mode of operation. In an embodiment, when no change in a channel condition is observed, value for the PSFTC may be fixed. Upon introduction of signal distortion in a channel, changes in the channel condition may observed and may lead to a change in value of the SCC and the 2D-QBCM.
[0036] When the MIMO transceiver 200 is initialized in the transmitter mode, the MTCM 212 may determine the PSTFC using pre-set TP values and may maintain the determined PSTFC in persistent memory. These pre-set TP values may be utilized by the WG.sub.X module 204 for reducing the computational complexity.
[0037] The PCMU 214 may be connected to the MTCM 212 and to each of the MTS.sub.X 202. The PCMU 214 may receive precoding and mapping related configuration parameter from the MTCM 212. The PCMU 214 may receive transmission data (TD) as input to the MIMO transceiver during operating under the transmission mode. The PCMU 214 may perform encoding of the TD using the parameters received from the MTCM 212. The PCMU 214 may also transmit encoded data to the MTS.sub.X 202 through a connector C1.sub.X 216 based on a control signal received from the MTCM 212 through a connector C7.sub.X 228.
[0038] The connector C1.sub.X 216 may be used to send Quadrature amplitude modulation (QAMx) data by the PCMU 214 to WG.sub.X module 204 and ‘x’ may have values from 1 to P (i.e., number to transmitters). Further, the connector C7.sub.X 228 may be used to send control parameters from the MTCM 212 to PCMU 214. The control parameters may correspond to precoding and mapping of the transmission data.
[0039] In an embodiment, the PCMU 214 may encode input transmission data received from the interface I1 and map the encoded input transmission data to different transmit chains. The pre-coding may be used before multicarrier modulation to provide additional gains in terms of reliability or throughput in presence of multi-antennas at the MIMO transceivers. After the pre-coding of the incoming modulated data (i.e. data to be transmitted), the pre-coded data (i.e. data to be transmitted) may be mapped to the different transmit chains for realization of multiple transmitter units. As an example, each of the transmit chains (MTS.sub.X 202) may have the WG.sub.X module 204, the WM.sub.X module 206, and the WCM.sub.X module 208.
[0040] The MTCM 212 may be connected to the WG.sub.X module 204 through a connector C8.sub.X, to the WT.sub.X module 206 through a connector C9.sub.X, to the WCM.sub.X module 208 through a connector C10.sub.X, and to the PCMU 214 through the connector C7.sub.X 228 to facilitate providing relevant configuration information depending on the operation mode of the MIMO transceiver system 100. In an example, the connector C8.sub.X 226 may be used to send the PSFTC value from the MTCM 212 to the WG.sub.X module 204, where ‘x’ may have values from 1 to P (i.e., number to transmitters). The distinguishing aspect may be transmission of the PSFTC value. Further, the connector C9.sub.X may be used to send configuration parameters related to waveform transformation from the MTCM 212 to the WT.sub.x module 206, where ‘x’ may have values from 1 to P (i.e., number to transmitters). Furthermore, the connector C10.sub.X may be used to transmit the primary configuration parameters stored in the MTCM 212 to the WCM.sub.X module 208. Here, ‘x’ may have values from 1 to P (i.e., number to transmitters). The connector C10.sub.X may be used to send configuration parameters related to waveform conditioning to the WCM.sub.X module 208.
[0041] In the MIMO transceiver system 100, for each of the MTS.sub.X module 202 there may be a corresponding WG.sub.X module 204. The WG.sub.X module 204 may receive an encoded transmission data from the PCMU 214 through a connector C1.sub.X 216 and may generate a waveform for the received encoded transmission data. The WG.sub.X module 204 may also receive the PSFTC value from the MTCM 212 through connector C8.sub.X 226. The MTCM 212 may use the received PSFTC value to generate a Circulant Dirichlet Pulse Shaped-Orthogonal Time Frequency Space-Time Frequency (CPS-OTFS-TF) signal. Further, a CPS-OTFS waveform may be generated corresponding to the generated CPS-OTFS-TF signal. The generated CPS-OTFS waveform may be transmitted with reduced complexity. The generated CPS-OTFS waveform may be frequency localized and may have unitary in property which may facilitate to reduce peak to average power ratio and Out of Band (OOB) radiation.
[0042] The CPS-OTFS-TF signal generated by the WG.sub.X module 204 may be received by the WT.sub.X module 206 through a connector C2.sub.X 218. As an example, the connector C2.sub.X 218 may be used to send CPS-OTFS time-frequency transmission signal (CPS-OTFS-TF-TS) by the WG.sub.X module 204 to the WT.sub.X module 206. Here, ‘x’ may have values from 1 to P (i.e., number to transmitters). A distinguishing aspect is transmission of the CPS-OTFS-TF-TS.sub.X through the connector C2.sub.X 218. Further, the WT.sub.X module 206 may receive transformation related configuration parameters from the MTCM 212 through a connector C9.sub.X 224. The WT.sub.X module 206 may transform the received CPS-OTFS-TF signal using transformation related configuration parameters to generate a circular pulse shaped Orthogonal Time Frequency Space (OTFS) signal in time domain. The WT.sub.X 206 module may convert every set of time symbols (N) of time-frequency domain transmission signal into time domain transmission signal using N-point IFFT. Here, ‘M’ number of N-point IFFTs may be required as there are ‘MN’ number of time-frequency domain transmission signals present in one of CPS-OTFS-TF signal. The WT.sub.X module 206 may send the transformed Circulant Dirichlet Pulse Shaped-Orthogonal Time Frequency Space-Transmission Data (CPS-OTFS-TD) signal to the WCM.sub.X module 208 through a C3.sub.X connector 220. In an example, the C3.sub.X connector may be used to send sequenced CPS-OTFS-TD-TS.sub.X from the WT.sub.X module 206 to the WCM.sub.X module 208. Here, ‘x’ can have values from 1 to P (i.e., number to transmitters). A distinguishing aspect here is the transmission of CPS-OTFS time domain transmission signal through the C3.sub.X connector 220. An enhancement in performance of the WT.sub.X module 206 is generation of the CPS-OTFS-TD signal by implementing M number of N-point IFFT as compared to conventional N number of M-point IFFT, where M is very high than N.
[0043] Upon receiving the CPS-OTFS-TD signal from the WT.sub.X module 206, the WCM.sub.X module 208 may condition the received CPS-OTFS-TD signal. The WCM.sub.X module 208 may insert a cyclic prefix (CP) to the received CPS-OTFS-TD signal using a pre-set CP parameter received from the MTCM 212 through a connector C10 222. The CP may act as a buffer region or as a guard interval to protect the transmitted signals from inter-symbol interference. The WCM.sub.X module 208 may transmit the CP-CPS-OTFS-TD signal through a corresponding dedicated transmit antenna (DTA.sub.X) 210. Fewer number of cyclic prefixes may be performed since a smaller number of M-point IFFT are required.
[0044] In an embodiment, when the wireless MIMO transceiver 200 operates under the transmitter mode, the MTCM 212 may determine the PSTFC as a first primary parameter for generation of a circularly pulse shaped waveform. The MTCM 212 may determine the PSTFC by using the multiple secondary parameters such as pre-set transmission parameters (TP) e.g., number of time-symbols (N), transmission duration (T) and number of sub-carriers (M). The values of the TP (e.g., M, N and T) may be stored in the persistent memory of the MTCM 212. By using the TP, the MTCM 212 may determine number of sub-carrier positions as e.g., r=N*M. Then the MTCM 212 may compute PSTFC for each ‘r’ represented by ‘λ(r)’ using M & N values of TP and ‘r’, and time-frequency coefficient values span from ‘λ(0)’ to ‘λ(MN-1)’. In an example, the circularly pulse shaped time-frequency coefficient value ‘(λ)’ may be computed as:
[0045] Where g[n] is unitary and frequency localized pulse signal. For example, g may be a Dirichlet Pulse. Further, the MTCM 212 may store the determined PSTFC in its own persistent memory.
[0046] Referring now to
[0047] Upon booting of the wireless MIMO transceiver system 100, an expected mode of operation of the wireless transceiver 200-1 may be determined. The determined mode of operation of the wireless MIMO transceiver 200-1 may be any of a transmitter mode (T-mode) or a receiver mode (R-Mode). The MTCM 238 may set the wireless MIMO transceiver 200-1 in the determined mode of operation. Further, the MTCM 238 may activate corresponding modules of the wireless MIMO transceiver 200-1 based on the determined mode of operation. If the determined operating mode is the R-mode, the MTCM 238 may activate the DCSU 240, the DEM.sub.Y module 232, the CEM.sub.Y module 234, and the WCM.sub.Y module 236. Additionally, the MTCM 238 may store the multiple primary and the secondary parameters. The secondary parameters may be used when the wireless MIMO transceiver 200-1 operates in the receiver operation mode. The multiple secondary parameters may include Prefix and Postfix Configuration Parameters (PPCP), coding and decoding related parameters, modulation and demodulation related configuration parameters, and Transmission Parameters (TP) including at least one of number of time symbols (N), transmission duration (T), number of sub-carriers (M), circulant delay value, channel attenuation factor, and Doppler value. First secondary parameter may correspond to the demodulation related configuration parameters, the second secondary parameter may correspond to the sequencing related configuration parameters, and the third secondary parameter may correspond to the decoding related parameters.
[0048] When the MIMO transceiver 200-1 is initialized in the receiver mode, the MTCM 238 may determine the 2D-QBCM using the pre-set values of the TP and may maintain the determined 2D-QBCM in its persistent memory. These pre-set TP values may be utilized by the CEM.sub.Y module to reduce computational complexity.
[0049] In an embodiment, the DCSU 240 may be connected the DEM.sub.Y module 232 through a connector C6.sub.Y, 242 where ‘Y’ can have values from 1 to Q (i.e., number to receivers). The DCSU 240 may obtain decoding and sequencing related configuration parameters from the MTCM 238 through a connector C14 248. The DCSU 240 may arrange and sequence estimated data received from multiple DEM modules that correspond to each of the multiple MRS.sub.Y 230. Further, the DCSU 240 may sequence and decode estimated data to retrieve the transmission data received using MRS.sub.Y 230. Finally, the DCSU may output the decoded data through interface I2. In an example, the connector C6.sub.Y 242 may be used to send estimated data signal from the DEM.sub.Y module 232 to the DCSU 240. Here, ‘Y’ can have values ranging from 1 to Q (i.e., number to receivers). Further, the connector C14 248 may be used to send sequencing and decoding related configuration parameters from the MTCM 238 to the DCSU 240.
[0050] The WCM.sub.Y module 236 may receive the transmission signal from the Dedicated-Receiver-Antennas (DRA.sub.Y). The WCM.sub.Y module 236 may obtain waveform conditioning related configuration parameters from the MTCM 238 through a connector C11.sub.Y. The WCM.sub.Y module 236 may remove the cyclic prefix (CP) attached to the received signal (e.g., CPS-OTFS time domain signal) for retrieving a data signal. The received signal may also include noise which may be added during transmission through a time varying channel (TVC). Additionally, the received signal may be sampled at a rate based on a pre-set symbol duration and a number of sub-carriers received from the MTCM 238 through a C11.sub.Y connector 254. The WCM.sub.Y module 236 may send the conditioned signal to CEM.sub.Y module 234 through a connector C4.sub.Y 246. In an example, the connector C4.sub.Y 246 may be used to send Wireless Communication Signal (WCS) from the WCM.sub.Y module 236 to the CEM.sub.Y module 234. Here, ‘Y’ may have values from 1 to Q (number to receivers). Further, the C11.sub.Y connector 254 may be used to send configuration parameters from the MTCM 238 to the WCM.sub.Y module 236. Here, ‘Y’ may have values from 1 to Q (i.e., number to receivers). Also, the C11.sub.Y connector 254 may be used to send configuration parameters related to waveform conditioning.
[0051] The CEM.sub.Y module 234 may be connected to the WCM.sub.Y module 236, the DEM.sub.Y module 232, and the MTCM 238. The CEM.sub.Y module 234 may receive conditioned waveform from the WCM.sub.Y module 236 through the connector C4.sub.Y 246. The CEM.sub.Y module 234 may also obtain 2D-QBCM from the MTCM 238. The CEM.sub.Y module 234 may transform the conditioned waveform using the 2D-QBCM. This may be performed using a step-wise backward substitution and forward substitution for quasi-banded signal correction factor. The CEM.sub.Y module 234 may transform the received signal into an intermediate state using the backward substitution of lower triangular factorized 2D-QBCM. The intermediate state signal may further be transformed using a forward substitution of upper triangular factorized 2D-QBCM. As may be appreciated, purpose of the CEM.sub.Y module 234 may be to remove the channel effects which may be present in the received signal because of the time varying channel (TVC). Output of the WCM.sub.Y module 236 may be an input for the CEM.sub.Y module 234. Additionally, the CEM.sub.Y module 234 may further include linear minimum mean square error equalizer for cancelling channel effects from the received signal that facilitates to estimate data symbols. In an aspect, the CEM.sub.Y module 234 may enable generation of a channel equalized received signal (CE-RS.sub.Y) by transforming the time domain received waveform using 2D-QBCM determined by the MTCM 238 thereby significantly reducing complexity of the receiver as compared to conventional LMMSE receiver.
[0052] In an embodiment, the DEM.sub.Y module 232 may be connected to the CEM.sub.Y module 234, the DCSU 240, and the MTCM 238. The DEM.sub.Y module 232 may receive Channel Equalized Received Signal (CE-RS.sub.Y) from the CEM.sub.Y module 234 through a connector C5.sub.Y 244 and OTFS match filter coefficients (i.e., demodulation related configuration parameter) and transmission parameters (i.e., values of M & N) from the MTCM 238 through a connector C13.sub.Y 250. In an example, the connector C5.sub.Y 244 may be used to send Circularly Pulse Shaped-Orthogonal Time Frequency Space time domain Channel Equalized Signal (CPS-OTFS-TD-CES) from the CEM.sub.Y module 234 to the DEM.sub.Y module 232. Here, ‘Y’ may have values from 1 to Q (i.e., number to receivers). Further, the connector C13.sub.Y 250 may be used to send configuration parameters from the MTCM 238 to the DEM.sub.Y module 232. Here, ‘Y’ may have values from 1 to Q (i.e., number to receivers). The configuration parameters may facilitate to perform signal demodulation. The DEM.sub.Y module 232 may perform signal demodulation and signal transformation (i.e., time to frequency transformation) Finally, the DEM.sub.Y module 232 may estimate/recover the transmitted data symbols using an Orthogonal Time Frequency Space (OTFS) matched filter where parameters may be received from the MTCM 238.
[0053] Additionally, the DEM.sub.Y module 232 may transform an incoming time domain Channel Equalized Received Signal (T-CE-RSx) to time frequency domain Channel Equalized Received Signal (TF-CE-RSx). This transformation may be done by converting finite sequence of samples of the time domain signal into a same length sequence of samples of the frequency domain signal. Also, the transformation may be performed by using ‘M’ number of N-point FFT. In the end, the transmitted data may be estimated by using the OTFS matched filter. As may be appreciated, the DEM.sub.Y module 232 may enable implementation of ‘M’ number of N-point FFT to transform time domain CE-RSx to time-frequency domain CE-RSx as compared to conventional ‘N’ number of M-point FFT, where ‘M’ is extremely high than ‘N’.
[0054] In an embodiment, when the wireless MIMO transceiver 200-1 operates under the receiver mode, the MTCM 238 may determine signal correction coefficient (SCC) for transforming the received signal (RS). The MTCM 238 may determine the SCC based on the transmission parameters (TP) stored in its own persistent memory. The TP parameters may be such as circulant delay value, channel attenuation factor, Doppler value for each of the received paths, signal power and noise variance. As the received RS is in time domain, the SCC may also vary with time. To reduce the receiver's complexity, the MTCM 238 may determine a 2-dimensional (e.g., time and frequency based) signal correction matrix (SCM) which may represent each element as the SCC. Further, the SCM may be decomposed into 2-dimensional quasi-banded channel matrix (2D-QBCM) with lower and upper factorization.
[0055] The MTCM 238 may determine the 2D-QBCM by circular shifting of channel attenuation factor and 2D-Doppler-matrix (2D-DM). The MTCM 238 may determine the 2D-DM by arranging doppler values on diagonal of a MN×MN zero matrix. Further, the MTCM 238 may decompose the 2D-QBCM such that combined (i.e., product) value of the decomposed 2D-QBCM may be equivalent to the 2D-QBCM. The purpose of this factorization is to generate low complexity values having retained the original SCC. As an example, the MTCM 238 may determine the 2D-QBCM using a LU matrix decomposition (i.e., product of a lower triangular matrix and an upper triangular matrix). The MTCM 238 may store the 2D-QBCM in its own persistent memory and may send the 2D-QBCM to the Channel-Equalizer-Module (CEMy) through the C12.sub.Y connector. In an embodiment, the MTCM 238 may store the configuration parameters and the determined transceiver configuration parameters in its own persistent memory.
[0056] Referring now to
[0057] At step 304, the wireless MIMO transmitter may generate for each of the multiple transmit chains a CPS-OTFS time frequency signal based on a first primary parameter from multiple primary parameters. In an example, WG.sub.X module 204 may obtain PSTFC values λ(r) from the MTCM 212 using the C8.sub.X connector 226. The WG.sub.X module 204 may obtain a portion of the QAM data identified for a specific transmitter from the PCMU 214 through the C1.sub.X connector 216. This proportion of the QAM data may be represented as QAM.sub.X. The WG.sub.X module 204 may generate a circular pulse shaped time-frequency domain transmission signal (CPS-OTFS-TF-TSx) corresponding to the QAMx data symbols by scaling the QAMx data symbols using the PSTFC values λ(r). The generated CPS-OTFS-TF-TSx may be unitary and frequency localized as the PSTFC values are unitary and frequency localized. The generation of CPS-OTFS-TF-TSx may have a log-linear order of complexity. Further, the CPS-OTFS-TF-TSx may be sent to WT.sub.X module 206 using the C2.sub.X connector 218.
[0058] In an embodiment, value of the first primary parameter may be determined based on a first predefined algorithm. The multiple primary parameters may include a Pulse Shaped Time-Frequency Coefficient (PSTFC), a Signal Correction Coefficient (SCC), and 2-Dimensional Quasi-Banded Channel Matrix (2D-QBCM). The first primary parameter may be the PSTFC. Also, the multiple secondary parameters may include Prefix and Postfix Configuration Parameters (PPCP), coding and decoding related parameters, modulation and demodulation related configuration parameters, and Transmission Parameters (TP) including at least one of number of time symbols, transmission duration, number of sub-carriers, circulant delay value, and Doppler value.
[0059] At step 306, the wireless MIMO transmitter may convert for each of the multiple transmit chains, the CPS-OTFS time frequency signal to a CPS-OTFS time domain signal based on at least one of multiple secondary parameters. A first plurality of N-point Inverse Fast Fourier Transform (IFFT) may be employed on the CPS-OTFS time frequency signal. The first plurality may correspond to the number of sub-carriers and N may correspond to a set of time symbols. In an embodiment, the WT.sub.X module 206 may obtain the CPS-OTFS-TF-TSx from the WG.sub.X module 204 through the C2.sub.X connector 218. The WT.sub.X module 206 may obtain waveform transformation related parameters from the MTCM 212 through the connector C9.sub.X 224. In an example, the waveform transformation related parameters obtained may be such as transmission duration (T), time symbols (N), number of sub-carriers (M).
[0060] At step 308, each of a set of time symbols within the CPS-OTFS time frequency signal may be converted into a time domain transmission signal CPS-OTFS time domain signal using the first plurality of N-point Inverse Fast Fourier Transform (IFFT). The WT.sub.X module 206 may transform the CPS-OTFS-TF-TSx into the CPS time domain transmission signal (CPS-OTFS-TD-TSx) for transmission. The transformation may be done by converting a finite sequence of samples of the frequency domain signal into a same length sequence of samples of a time domain signal. Additionally, the transformation may be done by performing an IFFT operation with log-linear order of complexity.
[0061] The WT.sub.X module 206 may convert every set of time symbol (N) of time-frequency domain transmission signal into a time domain transmission signal using M number of N-point IFFTs. The M number of N-point IFFTs may be required as there are a total MN number of time-frequency domain transmission signals present in one CPS-OTFS symbol. The WT.sub.X module 206 sequenced CPS-OTFS-TD-TSx from M number of N-point-IFFT may generate sequenced CPS-OTFS-TD-TSx corresponding to data to be transmitted. The disclosure may facilitate to generate the CPS-OTFS-TD transmission signal by implementing M number of N-point IFFT as compared to conventional N number of M-point IFFT, where M is exceedingly higher than N. Further, the sequenced CPS-OTFS-TD-TSx may be transmitted to WCM.sub.X module 208 through the C3.sub.X connector 220.
[0062] At step 310, a Cyclic Prefix (CP) may be inserted to the CPS-OTFS time domain signal based on one of the multiple secondary parameters. The WCM.sub.X module 208 may add prefix and postfix values into a time-domain transmission signal. The WCM.sub.X module 208 may obtain sequenced CPS-OTFS-TD-TSx from the WT.sub.X module 206 through the C3.sub.X connector 220. The WCM.sub.X module 208 may obtain prefix and postfix configuration parameters (PPCP) from the MTCM 212 through the connector C10.sub.X 222. The WCM.sub.X module 208 may add cyclic prefix (CP) to the sequenced CPS-OTFS-TD-TSx using the PPCP. The cyclic prefix may act as a buffer region or as a guard interval to protect the transmitted signals from inter-symbol interference.
[0063] At step 312, in response to inserting the CP, the CPS-OTFS time domain signal may be transmitted via an associated transmit antenna from the plurality of transmit antennas.
[0064] Referring now to
[0065] At step 404, the wireless MIMO receiver may decode for each of the plurality of receive chains, the sequenced data to retrieve a transmitted data based on a third secondary parameter of the plurality of secondary parameters. As an example, the third secondary parameter may correspond to the decoding related parameters. The DCSU 240 may obtain sequencing and decoding related configuration parameters from the MTCM 238. Further, the DCSU 240 may sequence and decode the estimated data to obtain the transmitted data. The estimated data may first be sequenced using sequencing related configuration data received from the MTCM 238. Further, the sequenced data may be decoded to retrieve the transmitted data.
[0066] At step 406, the wireless MIMO receiver may provide for each of the plurality of receive chains, the retrieved transmitted data. The DCSU 240 may output the retrieved transmitted data through the I2 interface.
[0067] Referring to
[0068] The DEM.sub.Y module 232 may obtain the CPS-OTFS-TD-CES from the CEM.sub.Y module 234 through the C5.sub.Y connector 244. The DEM.sub.Y module 232 may obtain OTFS match filter coefficient from the MTCM through the C13.sub.Y connector 250.
[0069] At step 504, for each of the plurality of receive chains, the wireless MIMO receiver may convert the CPS-OTFS time domain channel equalized signal to a CPS-OTFS time frequency channel equalized signal by employing a first plurality of N-point Fast Fourier Transform (FFT) on CPS-OTFS time domain channel equalized signal. The DEM.sub.Y module 232 may transform the CPS-OTFS-TD-CES to CPS-OTFS-TF-CES. DEM.sub.Y module 232 may convert finite sequence of samples of the CPS-OTFS-TD-CES into a same length sequence of samples of frequency domain signal. This transformation may be done by implementing an N-point FFT.
[0070] At step 506, the wireless MIMO receiver may estimate for each of the plurality of receive chains, a data signal from the CPS-OTFS time frequency channel equalized signal based on a first secondary parameter of the plurality of secondary parameters, e.g., the first secondary parameter may correspond to demodulation related configuration parameters. The DEM.sub.Y module 232 may estimate the data signal by implementing an Orthogonal Time Frequency Space (OTFS) match filter on the CPS-OTFS-TF-CES. Subsequently, the DEM.sub.Y module 232 may send the estimated data signal to The DCSU 240 through the C6.sub.Y connector 242.
[0071] Referring now to
[0072] At step 604, the wireless MIMO receiver may remove a Cyclic Prefix (CP) attached to the CPS-OTFS time domain signal to retrieve the CPS-OTFS time domain signal. The WCM.sub.Y module 236 may remove the CP from the RS for retrieving the data signal, and the RS may include noise which may be added during transmission via time varying channel (TVC). The WCM.sub.Y module 236 may sample the RS based on the TP such as transmission duration (T) and number of sub-carriers (M). Further, the WCM.sub.Y module 236 may send the waveform conditioned signal (WCS) to the Channel-Equalizer-Module (CEM.sub.Y) through the connector C4.sub.Y.
[0073] At step 606, the wireless MIMO receiver may sample the CPS-OTFS time domain signal based on at least one of the plurality of secondary parameters. At step 608, the wireless MIMO receiver may generate the conditioned CPS-OTFS time domain signal in response to sampling the CPS-OTFS time domain signal.
[0074] Referring now to FIG.7, is a flow diagram 700 of an exemplary process for transforming conditioned CPS-OTFS time domain signal, in accordance with some embodiments of the present disclosure. At step 702, the wireless MIMO receiver may transform the conditioned CPS-OTFS time domain signal into an intermediate state signal using backward substitution of lower triangular factorized 2D-QBCM. At step 704, the wireless MIMO receiver may transform the intermediate state signal further using forward substitution of upper triangular factorized 2D-QBCM. The CEM.sub.Y module 234 may transform the WCS using the 2D-QBCM to determine CPS-OTFS time domain channel equalized signal (CPS-OTFS-TD-CES). The CEM.sub.Y module 234 may transform the WCS into an intermediate state using the backward substitution of lower triangular factorized 2D-QBCM. The intermediate state signal may further be transformed using a forward substitution of upper triangular factorized 2D-QBCM. Further, to equalize the channel effect, the CEM.sub.Y module 234 may perform circular shifting of the transformed WCS by a doppler delay factor. The CEM.sub.Y module 234 may further modulate the circular shifted WCS by a channel sparsity factor to determine T-CES. The CEM.sub.Y module 234 may obtain the doppler delay factor and channel sparsity factor from the MTCM 238 through the C12.sub.Y connector 252. Further, the CEM.sub.Y module 234 may send the CPS-OTFS-TD-CES to the DEM.sub.Y module 232 through the C5.sub.Y connector 244.
[0075] The disclosed methods and systems may be implemented on a conventional or a general-purpose computer system, such as a personal computer (PC) or server computer. It will be appreciated that, for clarity purposes, the above description has described embodiments of the invention with reference to different functional units and processors. However, it will be apparent that any suitable distribution of functionality between different functional units, processors or domains may be used without detracting from the invention. For example, functionality illustrated to be performed by separate processors or controllers may be performed by the same processor or controller. Hence, references to specific functional units are only to be seen as references to suitable means for providing the described functionality, rather than indicative of a strict logical or physical structure or organization.
[0076] Various embodiments of the invention provide a transmission method and system through a wireless Multiple Input Multiple Output (MIMO) transmitter for dividing transmission data into a plurality of transmit chains corresponding to each of a plurality of antennas. The method and system may generate for each of the plurality of transmit chains, a Circularly Pulse Shaped Orthogonal Time Frequency Space (CPS-OTFS) time frequency signal based on a first primary parameter from a plurality of primary parameters. The value of the first primary parameter may be determined based on a first predefined algorithm. The method and system may convert, for each the plurality of transmit chains, the CPS-OTFS time frequency signal to a CPS-OTFS time domain signal based on at least one of a plurality of secondary parameters. A first plurality of N-point Inverse Fast Fourier Transform (IFFT) may be employed on the CPS-OTFS time frequency signal. Further, the first plurality may correspond to the number of sub-carriers and N corresponds to a set of time symbols.
[0077] Another embodiment of the invention provides a transmission method and system through a wireless Multiple Input Multiple Output (MIMO) receiver. The receiver may transform for each of a plurality of receive chains, a conditioned Circularly Pulse Shaped Orthogonal Time Frequency Space (CPS-OTFS) time domain signal to a CPS-OTFS time domain channel equalized signal based on a second primary parameter from a plurality of primary parameters. A second primary parameter may be determined based on a second predefined algorithm. The method and system may convert for each of the plurality of receive chains, the CPS-OTFS time domain channel equalized signal to a CPS-OTFS time frequency channel equalized signal by employing a first plurality of N-point Fast Fourier Transform (FFT) on CPS-OTFS time domain channel equalized signal. The first plurality may correspond to a number of sub-carriers and N corresponds to a set of time symbols. The method and system may estimate, for each of the plurality of receive chains, a data signal from the CPS-OTFS time frequency channel equalized signal based on a first secondary parameter of the plurality of secondary parameters. The data signal may correspond to the plurality of receiver antennas.
[0078] As will be appreciated by those skilled in the art, the techniques described in various embodiments discussed above are not routine, or conventional, or well understood in the art. Moreover, benefit of the present invention may include providing an improved wireless MIMO transceiver that has an ability to control waveform dispersion while keeping computational complexity within limits, thus making the MIMO transceiver suitable for realizing high mobility edge communication applications. This may be achieved by applying a waveform dispersion control where the transmitter may use a modulator for modulating data that is to be transmitted using CPS-OTFS in which transmitted signal waveform may be circular and spans a whole frame duration. Implementation of the CPS-OTFS may have features such as (a) implementing circularly pulse shaped OTFS to reduce peak to average power ratio, and (b) implementing frequency-localized OTFS to reduce the OOB radiation. In addition, this may be achieved by reducing computational complexity and may be executed by implementing low complexity CPS-OTFS based multi-transmitter with log-linear order of complexity for signal processing, and by implementing low complexity channel equalization of the received signal by multi-receiver using quasi-banded signal correction factor(s) derived from channel characteristics/condition. Further, the multi-receiver may transform the received signal by sequentially implementing backward and forward substitution for quasi-banded signal correction factor(s) respectively.
[0079] The specification has described method and system for data transmission. The illustrated steps are set out to explain the exemplary embodiments shown, and it should be anticipated that ongoing technological development will change the manner in which particular functions are performed. These examples are presented herein for purposes of illustration, and not limitation. Further, the boundaries of the functional building blocks have been arbitrarily defined herein for the convenience of the description. Alternative boundaries can be defined so long as the specified functions and relationships thereof are appropriately performed. Alternatives (including equivalents, extensions, variations, deviations, etc., of those described herein) will be apparent to persons skilled in the relevant art(s) based on the teachings contained herein. Such alternatives fall within the scope and spirit of the disclosed embodiments.
[0080] Furthermore, one or more computer-readable storage media may be utilized in implementing embodiments consistent with the present disclosure. A computer-readable storage medium refers to any type of physical memory on which information or data readable by a processor may be stored. Thus, a computer-readable storage medium may store instructions for execution by one or more processors, including instructions for causing the processor(s) to perform steps or stages consistent with the embodiments described herein. The term “computer-readable medium” should be understood to include tangible items and exclude carrier waves and transient signals, i.e., be non-transitory. Examples include random access memory (RAM), read-only memory (ROM), volatile memory, nonvolatile memory, hard drives, CD ROMs, DVDs, flash drives, disks, and any other known physical storage media.
[0081] It is intended that the disclosure and examples be considered as exemplary only, with a true scope and spirit of disclosed embodiments being indicated by the following claims.