MULTICARRIER TRANSCEIVER AND METHOD FOR PRECODING SPATIALLY MULTIPLEXED OFDM SIGNALS IN A WIRELESS ACCESS NETWORK

• US 20120170672A1
• Filed: 03/13/2012
• Published: 07/05/2012
• Est. Priority Date: 09/03/2003
• Status: Abandoned Application

• Current Assignee: Lakshmipathi Sondur
• Original Assignee: Lakshmipathi Sondur
• Inventors: Sondur, Lakshmipathi
• Application Number:
  US13/419,024
• Publication Number:
  US 20120170672A1
• Time in Patent Office: Days
• US Class Current: 375/260
• CPC Class Codes: H04B 7/0617 for beam forming
• CPC Class Codes: H04B 7/0697 using spatial multiplexing
• CPC Class Codes: H04B 7/086 using weights depending on external parameters, e.g. direction of arrival [DOA], predetermined weights or beamforming
• CPC Class Codes: H04L 25/0226 sounding signals per se
• CPC Class Codes: H04L 25/0242 using matrix methods
• CPC Class Codes: H04L 27/265 Fourier transform demodulators, e.g. fast Fourier transform [FFT] or discrete Fourier transform [DFT] demodulators H04L27/26524 takes precedence

Abstract

A multicarrier transceiver for communicating spatially multiplexed orthogonal frequency division multiplexed (OFDM) signals over two or more spatial channels in a wireless access network in accordance with an orthogonal frequency division multiple access technique with a plurality of antennas is generally disclosed herein. In some embodiments, the multicarrier transceiver comprises a matrix generator to generate a matrix for precoding transmission symbols based an indicator received from a receiving station, the indicator being based at least in part on channel characteristics. The multicarrier transceiver also includes a precoder to multiply the transmission symbols by the matrix for transmission on groups of subcarriers that comprise the OFDM signals using the antennas for transmission through two or more spatial channels, each of the two or more spatial channels to concurrently convey separate spatially multiplexed data streams over a same set of subcarriers.

Claims

1. A multicarrier transceiver for communicating spatially multiplexed orthogonal frequency division multiplexed (OFDM) signals over two or more spatial channels in a wireless access network in accordance with an orthogonal frequency division multiple access technique with a plurality of antennas, the transceiver comprising:

a matrix generator to generate a matrix for precoding transmission symbols based an indicator received from a receiving station, the indicator being based at least in part on channel characteristics; and

a precoder to multiply the transmission symbols by the matrix for transmission on groups of subcarriers that comprise the OFDM signals using the antennas for transmission through two or more spatial channels, each of the two or more spatial channels to concurrently convey separate spatially multiplexed data streams over a same set of subcarriers.

2. The multicarrier transceiver of claim 1 further comprising RF circuitry coupled to the plurality of antennas to generate RF signals for transmission from baseband signals provided by the precoder, the RF signals being precoded for receipt by the receiving station.

3. The multicarrier transceiver of claim 2 wherein the indicator is a precoding matrix indicator that is generated from the channel characteristics by the receiving station.

4. The multicarrier transceiver of claim 3 wherein the indicator corresponds to a codebook index of a precoding matrix for use in beamforming

5. The multicarrier transceiver of claim 4 further comprising circuitry to select a modulation level based on channel quality information provided by the receiving station.

6. The multicarrier transceiver of claim 4 wherein the multicarrier transceiver is configured to receive an indicator from the receiving station to indicate a number of transmission layers for transmission using the antennas.

7. The multicarrier transceiver of claim 6 wherein the precoding matrix is applied to the OFDM signals at baseband prior to upconversion and amplification by the RF circuitry and transmission by to the plurality of antennas.

8. A method for communicating spatially multiplexed orthogonal frequency division multiplexed (OFDM) signals over two or more spatial channels in a wireless access network in accordance with an orthogonal frequency division multiple access technique with a plurality of antennas, the method comprising:

generating a matrix for precoding transmission symbols based an indicator received from a receiving station, the indicator being based at least in part on channel characteristics; and

multiplying the transmission symbols by the matrix for transmission on groups of subcarriers that comprise the OFDM signals using the antennas for transmission through two or more spatial channels, each of the two or more spatial channels to concurrently convey separate spatially multiplexed data streams over a same set of subcarriers.

9. The method of claim 8 further comprising RF circuitry coupled to the plurality of antennas to generate RF signals for transmission from baseband signals provided by the precoder, the RF signals being precoded for receipt by the receiving station.

10. The method of claim 9 wherein the indicator is a precoding matrix indicator that is generated from the channel characteristics by the receiving station.

11. The method of claim 10 wherein the indicator corresponds to a codebook index of a precoding matrix for use in beamforming

12. The method of claim 11 further comprising selecting a modulation level based on channel quality information provided by the receiving station.

13. The method of claim 11 further comprising receiving an indicator that indicates a number of transmission layers for transmission to the receiving station using the antennas.

14. A method for precoding beamforming in a wireless access network that communicates using orthogonal frequency division multiplexed (OFDM) communication signals over a plurality of spatial channels, the method comprising:

transmitting OFDM training symbols over the spatial channels through a plurality of associated antennas;

receiving an indicator from a receiving station, the indicator being based at least in part on channel characteristics of the spatial channels measured by the receiving station based on the training symbols;

generating a matrix based on the indicator, the matrix being associated with a codebook;

applying the matrix at baseband to the transmission symbols to precode the transmission symbols for subsequent transmission to the receiving station through two or more spatial channels.

15. A mobile device for receiving precoded orthogonal frequency division multiplexed (OFDM) transmissions over a plurality of spatial channels, the mobile device comprising:

a receiver to receive OFDM training symbols over the spatial channels through a plurality of associated antennas;

processing circuitry to generate an indicator that is based at least in part on channel characteristics of the spatial channels measured from the training symbols, the indicator to indicate a matrix associated with a codebook for precoding of transmission symbols; and

a transmitter to transmit the indicator to a transmitting station,

wherein the receiver is configured to receive transmission symbols from the transmitting station that are precoded by application of the matrix.

16. The mobile device of claim 15 wherein the indicator is a precoding matrix indicator.

17. The mobile device of claim 16 wherein the transmission symbols received from the transmitting station are beamformed signals.