Receiver for and method of recovering transmitted symbols in a H-ARQ packet retransmission
View Patent ↗A receiver and method for recovering transmitted symbols in a H-ARQ packet retransmission. The method includes receiving a communication signal; determining components of the signal that are not attributed to the desired symbols; removing the unwanted components from the signal to generate a modified communication signal; determining the effective channel impulse response for the modified communication signal; generating a block filter using the effective channel impulse response; and filtering the modified communication signal using the block filter to remove the inter-code interference in the modified communication signal and recover the desired symbols.
1. A method of recovering transmitted symbols in a communication signal of a H-ARQ packet retransmission comprising:
receiving a communication signal;
determining inter-symbol interference components of the signal, wherein the inter-symbol interference components are estimated using previous transmissions of the packet;
removing the inter-symbol interference components from the signal to generate a modified communication signal;
determining an effective channel impulse response;
generating a block filter using the effective channel impulse response by determining
G (n)={[ H ·S(n)] H · H ·S(n)} −1 ·[ H ·S(n)] H , where S(n) represents channelization codes and H represents the effective channel impulse response; and
filtering the modified communication signal using the block filter to remove inter-code interference in the modified signal and recover desired symbols of the modified signal.
2. The method of claim 1 wherein the step of filtering the modified communication signal comprises multiplying block filter G (n)={[ H ·S(n)] H · H ·S(n)} −1 ·[ H ·S(n)] H by a stacked modified baseband
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to recover the desired symbols, where S(n) represents channelization codes y (n) is a baseband signal without components caused by symbols other than b (n), where b (n) is an estimate of b(n), the desired symbols, from previous transmissions of the packet and ┌L/P┐ represents a maximum number of symbols contributing to inter-symbol interference.
3. A receiver comprising:
a receiver front end for receiving a transmitted signal and converting the signal into a baseband signal;
a baseband signal processing block operatively coupled to the receiver front end for recovering transmitted symbols in a communication signal of a H-ARQ packet retransmission by receiving the baseband signal;
determining inter-symbol interference components of the baseband signal, wherein the inter-symbol interference components are estimated using previous transmissions of the packet; removing the inter-symbol interference components from the baseband signal to generate a modified communication signal; determining an effective channel impulse response;
generating a block filter using the effective channel impulse response by determining
G (n)={[ H ·S(n)] H · H ·S(n)} −1 ·[ H ·S(n)] H ,where S(n) represents channelization codes and H represents the effective channel impulse response; and
filtering the modified communication signal using the block filter to remove inter-code interference in the modified signal and recover desired symbols of the modified signal; and
a back end operatively coupled to the baseband signal processing block for receiving the recovered symbols and routing the symbols to an intended application.