Channel code design with causal side information at the encoder

The problem of channel code design for the M-ary input AWGN channel with additive discrete interference where the sequence of i.i.d. interference symbols is known causally at the encoder is considered. The code design criterion at high SNR is derived by defining a new distance measure between the input symbols of the Shannon's associated channel. For the case of binary-input channel, it is shown that it is sufficient to use only two symbols of the associated channel in the encoding as long as the distance spectrum of the code is concerned. This reduces the problem of code design for the binary-input AWGN channel with known interference to the design of binary codes for the AWGN channel with maximum Hamming distance.