Impact of Imperfect Channel Estimation on Regenerative Cooperative Networks using Coherent and Non-coherent Detection

Abstract: In this paper, we investigate the effect of imperfect channel estimation on decode-and-forward (DF) cooperative diversity networks. There are two phases, the broadcasting phase and the relaying phase. In the first phase, the source broadcasts the message to the relays via flat Rayleigh fading channels. Relays that are capable of correctly decoding the source message will be working in the later phase i.e. the relaying phase. Initially, the output signal-to-interference-plus-noise ratio (SINR) at the destination is derived. Error and outage probabilities are considered as the performance metrics and exact closed-form expressions are derived for the same. The closed-form expression for outage probability is obtained for both non-coherent and coherent detection methods. These results are used to study the impact of imperfect channel estimation on the regenerative cooperative network. Asymptotic expression for the average symbol error probability is also derived and the inferences are discussed.

Keywords: Outage probability, Error probability, decode-and-forward, Cooperative networks, Relaying, Co-channel Interference.