Feedforward of non-quantized precoding weights in a wireless communications system
View Patent ↗An apparatus and method to feedforward non-quantized precoding weights in an OFDM communication system includes a first step ( 300 ) of sending feedback information from a subscriber station (SS) to a base station (BS). A next step ( 302 ) includes deriving non-quantized weight information from the feedback information. A next step ( 304 ) includes transmitting symbols carrying the non-quantized weight information and non-precoded pilot symbols by the BS. A next step ( 305 ) includes receiving the information and symbols by the SS. A next step ( 306 ) includes estimating the non-quantized weights from the symbols carrying the non-quantized weight information and the non-precoded pilot symbols by the SS. A next step ( 308 ) includes decoding data from the BS by the SS using the estimated non-quantized weight information.
1. A method to feedforward non-quantized weights in an OFDM communication system, the method comprising the step of:
transmitting symbols carrying non-quantized weight information and non-precoded pilot symbols by a transmitter to at least one receiver;
receiving the symbols carrying non-quantized weight information and the non-precoded pilot symbols by the at least one receiver; and
estimating a non-quantized weights from the received symbols carrying the non-quantized weight information and the received non-precoded pilot symbols by the at least one receiver;
wherein the transmitting step includes the symbols carrying the non-quantized weight information being in subcarriers that are multiplexed between and in proximity to the non-precoded pilot symbols.
2. The method of claim 1 , further comprising an initial step of: constructing a sounding waveform with pilot symbols; and sending the sounding waveform from at least one receiver to a transmitter.
3. The method of claim 1 , further comprising an initial step of sending analog channel information including covariance matrix coefficients, channel coefficients, analog precoding weights describing channel conditions from at least one receiver to the transmitter.
4. The method of claim 3 further comprising the step of deriving non-quantized weights at the transmitter from the feedback information.
5. The method of claim 1 wherein the transmitting step includes deriving analog weights at the transmitter from received pilot symbols, control data symbols, and data traffic symbols from one or more receivers.
6. The method of claim 1 wherein the transmitting step includes deriving non-quantized weights at the transmitter from received codebook index feedback from one or more receivers.
7. The method of claim 1 wherein the estimating step includes estimating the channel on the subcarriers carrying the non-quantized weight information from the received non-precoded pilot symbols.
8. The method of claim 1 further comprising the step of at least one subscriber station decoding data from a base station using the estimated non-quantized weights.
9. A method to feedforward non-quantized weights in an OFDM communication system, the method comprising the step of:
sending feedback information from at least one subscriber station to a base station;
deriving non-quantized weights from the received feedback information from at least one subscriber station;
transmitting symbols carrying a non-quantized weight information and non-precoded pilot symbols by the base station to the at least one subscriber station;
receiving the symbols carrying non-quantized weight information and the non-precoded pilot symbols by the at least one subscriber station;
estimating the non-quantized weights from the received symbols carrying the non-quantized weight information and the received non-precoded pilot symbols by the at least one subscriber station; and
decoding data by at least one subscriber station using estimated non-quantized weight information;
wherein the transmitting step includes the symbols carrying the non-quantized weight information being in subcarriers located in the time-frequency space that are multiplexed between and in proximity to subcarriers containing the non-precoded pilot symbols.
10. The method of claim 9 wherein the feedback information of the sending step is a sounding waveform comprising pilot symbols.
11. The method of claim 10 wherein the sounding symbols also comprise analog channel information including covariance matrix coefficients, channel coefficients, and analog precoding weights.
12. The method of claim 9 wherein the feedback information of the sending step includes a codebook based precoding matrix index.
13. The method of claim 9 wherein the feedback information of the sending step is analog channel information including covariance matrix coefficients, channel coefficients, and analog precoding weights describing channel conditions.
14. The method of claim 9 , wherein the estimating step includes estimating a channel on the subcarriers carrying the non-quantized weight information from the received non-precoded pilot symbols.