Transmission of correlated senders over a Rayleigh fading multiple access channel

Abstract

We consider the transmission of information from two correlated senders to a common receiver through a Rayleigh fast fading multiple access channel. Each one of the senders is encoded independently using a turbo-like code and neither the correlation model nor the channel state information is assumed to be known at the encoder. Decoding is performed in an iterative way, exploiting the correlation between the senders. The noise variance and correlation model do not need to be known at the decoder site, since they can be estimated jointly with the decoding process. When perfect channel state information is available at the decoder site, the resulting performance is very close to (and in some cases outperforms) the theoretical limits obtained when separation between source and channel coding is assumed. The performance loss when the channel state information is not available at the decoder depends on the correlation strength, becoming smaller for highly correlated senders.