The impact of channel variation on integer-forcing receivers

Consider several single-antenna transmitters that wish to simultaneously communicate with a multiple-antenna receiver. Recent work has proposed the integer-forcing linear receiver architecture as an alternative to conventional linear receivers. The key idea is to first use linear equalization to obtain an integer-valued effective channel, then employ single-user decoders to recover integer-linear combinations of the messages, and finally solve these for the desired messages. For the special case where the channel matrix remains fixed for the duration of the codeword, it has been shown that integer-forcing can operate very close to the performance of optimal joint maximum likelihood decoding. In this paper, we investigate the impact of channel variation on the integer-forcing linear receiver and show it still retains an advantage over conventional linear receivers, despite the fact that the integer coefficients must remain fixed across the codeword duration.