Coded cooperation (CC) is a popular method used to mitigate slow fading in wireless communication. In CC, a pair of users help each other with relaying part of partner's data is investigated to extend wireless channel reach by cooperative diversity. Basing on that basic principle and taking advantage of a bidirectional property of data flows, instead of transmitting the each packet from each user in the second phase of CC, we propose to broadcast a joint packet with XOR-gated information of the two second packets from both users. Moreover, we have to solve some problems when using CC for the bi-directional transmission. The method is called Bi-directional relay for coded cooperation (BiCC). The throughput is increased and the quality is also improved based on mathematical analysis and simulation.
To follow up, we propose a multi-mode version of BiCC. This method even gives a higher throughput than BiCC but requires some signaling between the nodes. We show the performance comparison between Multi-mode BiCC (mmBiCC), BiCC and CC. Algorithms to implement mmBiCC are also provided.
On the other hand, partner selection is a process that must be carried out before the cooperation occurs. We propose two methods of partner selection called Most Most Shadowed User Priority and Maximum Average User-User Shadow Reciprocal Factor. We compare the performances of the two methods as well as analyse advantage and disadvantages when used with BiCC and Multi-mode BiCC.