ARQ-based Cooperative Communication Systems

In recent years, cooperative diversity technology has become a hot spot of the field of wireless communication. It is a new diversity technique handling the problem that several antennas can't be installed in mobile terminal. The technology also promotes the practical application process of MIMO. There are many research directions of cooperative communication, and applying automatic repeat request (ARQ) in cooperative communication to improve system reliability is the top concern of researchers in the modern information theory.In this paper, the cooperative communication system that applied ARQ technology was deeply studied. The bit error rate and the throughput are the mainly indicators in this paper. We compared the single-relay communication system to the multi-relay communication system. And there were four mainly parts of this paper:The first part introduced the present development of mobile communication, the key problem and background of applying ARQ in multi-relay cooperation communication system. The second part discussed the general situation of cooperation relay communication system. And classify of the relay model, ways of relay forward, and merger of diversity technology solutions are emphasized in this part. The third part introduced ARQ mechanism, discussed the thinking of the using ARQ mechanism of single-relay cooperation communication system in system performance and channel estimation error, etc. On this basis, the fourth part drew ARQ technology into cooperative double-relay and multi-relay communication system, and compared system performance between single-relay ARQ system and double-relay two jump ARQ system. Simulation of cooperative multi-relay system applied ARQ mechanism was also analyzed in this part, and two relay selections based on the load balance and the channel SNR equivalent substitution, were proposed.