Cooperation over Fading Channels: Channel Capacity and Source-Channel Coding
Cooperation is one of the main architectures for improving the performance of wireless networks. In this talk we consider two types of cooperative networks. We first consider the problem of relaying in the presence of multiple communicating pairs. This scenario is represented by the interference channel with a relay. We present the capacity region of the interference channel with a relay, for phase fading channels and for Rayleigh fading channels, in the very strong and in the strong interference regimes, when relay reception is good. Specifically, we show that there are situations in which the relay can be optimal for both communicating pair simultaneously.
We then consider the simultaneous application of the two main types of cooperation, namely relaying and feedback, to the interference channel model, and derive capacity regions in the very strong and in the strong interference regimes, when the channel is fading. We identify the gains provided by different feedback configurations. Lastly, we consider the problem of source-channel coding for the multiple-access-relay channel and show that when the channel is subject to i.i.d. fading, then informational separation is optimal. We also present two joint source-channel coding schemes. The schemes combine the correlation-preserving mapping and binning, and are the first joint source-channel codes presented for cooperative multiuser scenarios.