Back to results
US 7,570,696 B2Granted
Multiple input multiple output multicarrier communication system and methods with quantized beamforming feedback
AssigneeIntel Corporation
InventorsAlexander A. Maltsev, Ali S Sadri, Sergey A. Tiraspolsky, Alexander Flaksman, Alexei V Davydov
Life of this patent
Estimating the term…
Abstract
A multicarrier receiver generates a quantized transmit beamformer matrix ({tilde over (V)}) for each subcarrier of a multicarrier communication channel for use by a multicarrier transmitting station. The multicarrier receiver applies a corrected receiver beamformer matrix (ŨH) to received subcarriers signals generated by signals received from the transmitting station.
Claims34
A multicarrier transmitter comprising:
- transmit subcarrier beamformers to apply quantized transmit beamforming coefficients to a plurality of symbol-modulated subcarriers in a signal path before an inverse Fourier transform (IFFT) is performed on the symbol-modulated subcarriers,
- wherein the quantized transmit beamforming coefficients comprise predetermined numbers of bits for the subcarriers indicating amounts to weight an amplitude and shift a phase of an associated one or more subcarriers, and
- wherein the predetermined numbers of bits are lower during initial portions of a packet exchange between the multicarrier transmitter and a receiving station and are greater during subsequent portions of the packet exchange.
A multicarrier transmitter comprising:
- transmit subcarrier beamformers to apply quantized transmit beamforming coefficients to a plurality of symbol-modulated subcarriers in a signal path before an inverse Fourier transform (IFFT) is performed on the symbol-modulated subcarriers,
- wherein the quantized transmit beamforming coefficients comprise predetermined numbers of bits for the subcarriers indicating amounts to weight an amplitude and shift a phase of an associated one or more subcarriers,
- wherein each one of the transmit subcarrier beamformers is associated with one subcarrier of a multicarrier communication channel,
- wherein the transmitter further comprises a plurality of transmit antennas for transmitting a plurality of spatial streams on a corresponding plurality of spatial channels over a multicarrier communication channel,
- wherein a number of the spatial streams is less than or equal to a number of the transmit antennas, and
- wherein the quantized transmit beamforming coefficients for each subcarrier correspond to a quantized transmit beamforming matrix ({tilde over (V)}) for each subcarrier, the matrix being a unitary matrix having a number of rows equaling the number of the transmit antennas, and a number of columns equaling the number of the spatial streams,
- wherein elements of the quantized transmit beamforming matrix ({tilde over (V)})comprise an amplitude subfield and a phase subfield, each subfield having a predetermined number of bits.
4 more elements
A multicarrier transmitter comprising:
- transmit subcarrier beamformers to apply quantized transmit beamforming coefficients to a plurality of symbol-modulated subcarriers in a signal path before an inverse Fourier transform (IFFT) is performed on the symbol-modulated subcarriers,
- wherein the quantized transmit beamforming coefficients comprise predetermined numbers of bits for the subcarriers indicating amounts to weight an amplitude and shift a phase of an associated one or more subcarriers,
- wherein each one of the transmit subcarrier beamformers is associated with one subcarrier of a multicarrier communication channel,
- wherein the transmitter is part of a transmitting station and receives channel feedback information comprising a quantized transmit beamforming matrix ({tilde over (V)}) for each subcarrier from a receiving station, and
- wherein the receiving station measures signals received from the transmitting station to estimate a channel transfer matrix (H) for each subcarrier of the multicarrier communication channel, and generates the quantized beamforming matrix ({tilde over (V)}) for each subcarrier for transmission to the transmitting station in a response packet.
2 more elements
A multicarrier transmitter comprising:
- transmit subcarrier beamformers to apply quantized transmit beamforming coefficients to a plurality of symbol-modulated subcarriers in a signal path before an inverse Fourier transform (IFFT) is performed on the symbol-modulated subcarriers,
- wherein the quantized transmit beamforming coefficients comprise predetermined numbers of bits for the subcarriers indicating amounts to weight an amplitude and shift a phase of an associated one or more subcarriers,
- wherein the transmitter further comprises:
- processing circuitry to provide the quantized beamforming coefficients from a quantized beamforming matrix ({tilde over (V)}) received from a receiving station as part of channel feed back information;
- symbol mapping circuitry to generate the symbol-modulated subcarriers from spatial channel multiplexed bit streams for the transmit subcarrier beamformers;
- and
- inverse fast Fourier transform circuitry (IFFT) circuitry for each transmit antenna to perform a FFT on the symbol-modulated subcarriers after application of the quantized transmit beamforming coefficients by the transmit subcarrier beamformers.
4 more elements
A multicarrier transmitter comprising:
- transmit subcarrier beamformers to apply quantized transmit beamforming coefficients to a plurality of symbol-modulated subcarriers in a signal path before an inverse Fourier transform (IFFT) is performed on the symbol-modulated subcarriers,
- wherein the quantized transmit beamforming coefficients comprise predetermined numbers of bits for the subcarriers indicating amounts to weight an amplitude and shift a phase of an associated one or more subcarriers,
- wherein the transmitter is part of a first communication station and wherein the quantized transmit beamforming coefficients are used for transmitting a data packet to a second communication station,
- wherein the second communication station comprises a channel estimator to estimate a channel transfer matrix (H) for each subcarrier from a current packet sent by the first communication station and beamformer matrix calculation circuitry to generate the quantized transmit beamformer matrices ({tilde over (V)}) for use by the first communication station.
1 more element
A multicarrier transmitter comprising:
- transmit subcarrier beamformers to apply quantized transmit beamforming coefficients to a plurality of symbol-modulated subcarriers in a signal path before an inverse Fourier transform (IFFT) is performed on the symbol-modulated subcarriers,
- wherein the quantized transmit beamforming coefficients comprise predetermined numbers of bits for the subcarriers indicating amounts to weight an amplitude and shift a phase of an associated one or more subcarriers,
- wherein the transmitter is part of a multicarrier communication station which further comprises a multicarrier receiver, the multicarrier receiver comprising:
- a channel estimator to estimate a channel transfer matrix (H) for each subcarrier from a current packet sent by another multicarrier communication station;
- beamformer matrix calculation circuitry to generate quantized transmit beamformer matrix ({tilde over (V)}) for each subcarrier for use by the other communication station;
- and
- a plurality of receiver beamformers to combine in the frequency domain, subcarrier signals generated from receipt of a data packet from the other communication station in accordance with a receiver beamformer matrix (ŨH) for each subcarrier to separate constellation signals from each spatial channel,
- wherein beamformer matrix calculation circuitry further calculates the receiver beamformer matrices (ŨH) from the channel transfer matrix (H) and the quantized transmit beamformer matrix ({tilde over (V)}).
5 more elements
A multicarrier receiver comprising:
- a channel estimator to estimate a channel transfer matrix (H) for one or more subcarriers of a multicarrier communication channel;
- beamformer matrix calculation circuitry to generate a quantized transmit beamformer matrix ({tilde over (V)}) for each of the subcarriers from an associated one of the channel transfer matrices (H);
- and
- a plurality of receiver beamformers to combine input subcarrier signals in accordance with a receiver beamformer matrix (ŨH) for each subcarrier to separate constellation signals from each spatial channel,
- wherein the calculation circuitry calculates the receiver beamformer matrices (ŨH) from the channel transfer matrix (H) and the quantized transmit beamformer matrix ({tilde over (V)}) for an associated one of the subcarriers.
2 more elements
A method for communicating signals over a multicarrier communication channel comprising:
- applying quantized transmit beamforming coefficients to a plurality of symbol-modulated subcarriers;
- and
- performing an inverse fast Fourier transform to the symbol-modulated subcarriers after applying the quantized transmit beamforming coefficients,
- wherein the quantized transmit beamforming coefficients comprise predetermined numbers of bits for each subcarrier of a multicarrier communication channel indicating amounts to weight an amplitude and shift a phase of an associated subcarrier, and
- wherein the method further comprises receiving a quantized transmit beamformer matrix ({tilde over (V)}) for each subcarrier from a receiving station, wherein the receiving station measures signals received from a transmitting station to estimate a channel transfer matrix (H) for each subcarrier and generates the quantized beamforming matrix ({tilde over (V)}) for each subcarrier for transmission to the transmitting station, wherein the receiving station performs a singular value decomposition (SVD) on the channel transfer matrix (H) to generate the quantized beamforming matrix ({tilde over (V)}) for each subcarrier.
2 more elements
A method for communicating multicarrier communication signals over a multicarrier communication channel comprising:
- estimating a channel transfer matrix (H) for each subcarrier of the multicarrier communication channel;
- generating a quantized transmit beamformer matrix ({tilde over (V)}) for each subcarrier from an associated one of the channel transfer matrices (H);
- and
- combining input subcarrier signals in accordance with a receiver beamformer matrix (ŨH) for each subcarrier to separate constellation signals from each spatial channel,
- wherein the receiver beamformer matrix (ŨH) for a subcarrier is calculated from the channel transfer matrix (H) and the quantized transmit beamformer matrix ({tilde over (V)}) for the associated subcarrier, and
- wherein the input subcarrier signals were transmitted a transmitting station using the quantized transmit beamformer matrix ({tilde over (V)}).
3 more elements
A system comprising:
- one or more substantially omnidirectional antennas to receive signals through a multicarrier communication channel;
- a channel estimator to estimate a channel transfer matrix (H) for one or more subcarriers of the multicarrier communication channel;
- beamformer matrix calculation circuitry to generate a quantized transmit beamformer matrix ({tilde over (V)}) for each of the subcarriers from an associated one of the channel transfer matrices (H);
- and
- a plurality of receiver beamformers to combine input subcarrier signals in accordance with a receiver beamformer matrix (ŨH) for each subcarrier to separate constellation signals from each spatial channel,
- wherein the calculation circuitry calculates the receiver beamformer matrices (ŨH) from the channel transfer matrix (H) and the quantized transmit beamformer matrix ({tilde over (V)}) for an associated one of the subcarriers.
3 more elements
A machine-readable storage medium that stores instructions, which when executed by one or more processors, cause the processors to perform operations comprising:
- estimating a channel transfer matrix (H) for each subcarrier of a multicarrier communication channel;
- generating a quantized transmit beamformer matrix ({tilde over (V)}) for each subcarrier from an associated one of the channel transfer matrices (H);
- and
- combining input subcarrier signals in accordance with a receiver beamformer matrix (ŨH) for each subcarrier to separate constellation signals from each spatial channel,
- wherein the receiver beamformer matrix (ŨH) for a subcarrier is calculated from the channel transfer matrix (H) and the quantized transmit beamformer matrix ({tilde over (V)}) for the associated subcarrier, and
- wherein the input subcarrier signals were transmitted a transmitting station using the quantized transmit beamformer matrix ({tilde over (V)}).
3 more elements
Dependencies are inferred from the claim text.