Coded cooperation for BICM-OFDM

Coded cooperation is an attractive user cooperation scheme for wireless systems, where different parts of a coded packet are transmitted over different channels. In this paper, we propose a new approach to improve the performance of coded cooperation. We present cooperative maximum-ratio combining (C-MRC) based coded cooperation to guarantee full diversity even if the inter-user link is not ideal. Moreover, we combine bit-interleaved coded modulation (BICM) with orthogonal frequency division multiplexing (OFDM) to overcome frequency-selective fading. Taking possible decision errors at the cooperating sources into account, we develop a closed-form upper bound on the asymptotic worst-case pairwise error probability (PEP) of the considered C-MRC based coded cooperation scheme and obtain the diversity gain as function of free distance of the code and frequency diversity of the links. Furthermore, we discuss the optimization of the puncturing pattern based on the frequency diversity of the involved links. Simulation results corroborate the derived analytical results.