초록 ▼

Stations in an N×N multiple-input-multiple-output (MIMO) wireless network always puncture the weakest spatial channel. A receiving station determines channel state information for N spatial channels and feeds back to the transmitting station channel state information for only N−1 spatial

Stations in an N×N multiple-input-multiple-output (MIMO) wireless network always puncture the weakest spatial channel. A receiving station determines channel state information for N spatial channels and feeds back to the transmitting station channel state information for only N−1 spatial channels. The channel state information may include a beamforming matrix to cause the transmitting station to utilize N−1 spatial channels.

대표청구항 ▼

What is claimed is: 1. A method comprising: receiving a training sequence from a transmitter; estimating N spatial channels in a multiple-input-multiple-output (MIMO) system, wherein N is equal to a number of receiving antennas; performing singular value decomposition to determine an N×N trans

What is claimed is: 1. A method comprising: receiving a training sequence from a transmitter; estimating N spatial channels in a multiple-input-multiple-output (MIMO) system, wherein N is equal to a number of receiving antennas; performing singular value decomposition to determine an N×N transmit beamforming matrix; removing one transmit beamforming vector from the N×N transmit beamforming matrix to yield N−1 transmit beamforming vectors, wherein the one transmit beamforming vector removed corresponds to a weakest of the N spatial channels; and transmitting the N−1 transmit beamforming vectors to the transmitter. 2. The method of claim 1 wherein N is equal to four. 3. The method of claim 1 wherein N is equal to three. 4. A method comprising always puncturing one spatial channel in an N.times.N multiple-input-multiple-output (MIMO) wireless system to yield N−1 spatial channels, where N is equal to a number of receiving antennas and is greater than one, by always feeding back only N−1 transmit beamforming vectors from a receiver to a transmitter. 5. The method of claim 4 wherein N is equal to four. 6. The method of claim 4 wherein N is equal to three. 7. A computer-readable medium encoded with instructions that when executed by a computer cause the computer to perform: receiving a training sequence from a transmitter; estimating N spatial channels in a multiple-input-multiple-output (MIMO) system, wherein N is equal to a number of receiving antennas; performing singular value decomposition to determine an N×N transmit beamforming matrix; removing one transmit beamforming vector from the N×N transmit beamforming matrix to yield N−1 transmit beamforming vectors, wherein the one transmit beamforming vector removed corresponds to a weakest of the N spatial channels; and transmitting the N−1 transmit beamforming vectors to the transmitter. 8. The computer-readable medium of claim 7 wherein the channel state information includes a beamforming matrix to cause the transmitter to utilize N−1 spatial channels. 9. The computer-readable medium of claim 7 wherein the channel state information describes spatial channels in an orthogonal frequency division multiplexing (OFDM) multiple-input-multiple-output (MIMO) system. 10. A wireless communications device having N antennas, the wireless communications device having a combination of hardware and software components to determine and a weakest of N spatial channels and to always puncture the weakest of N spatial channels, wherein the wireless communications device includes a combination of hardware and software to transmit N−1 beamforming vectors to a transmitter for use in antenna beamforming into N−1 spatial channels, where N is greater than one. 11. The wireless communications device of claim 10 wherein the wireless communications device includes N−1 baseband data circuits to source data to a beamforming network. 12. The wireless communications device of claim 10 wherein N is equal to four, and three spatial channels are always used. 13. The wireless communications device of claim 10 wherein N is equal to three, and two spatial channels are always used.