Recent years, cooperative technology has taken a lot of attention since it can improve the bit error rate （BER） and lower the transmit power in radio mobile networks, especially when the direct channel between the source and the destination is poor. Cooperative multiple input multiple output （Co-lVlIMO） is a kind of MI- MO technique, where the multiple inputs and outputs are formed via cooperation. The capacity of Co-MIMO system over wireless channel has been investigated a lot, however few papers pay attention to the locations of the channel that may affect the probability distributions of the variable and the effect of antenna spatial correlation. The results can be achieved by choosing sub-channels that is not related to other sub-channels. This paper focu- ses on this problem. The simulation results show that once we search the partner we should consider trade offs cooperation get optimum system performance. It further investigates that cooperation between different terminals can reduce antenna spatial correlation, thereby increase the capacity and throughput of the system, and even reach the ideal capacity of MIMO system.
Network coding (NC), which works in the network layer, is an effective technology to improve the network throughput, by allowing the relay to encode the information from different users and ensuring the destination to retrieve the desired information. Employing network coding technique in a cooperative network can improve the network performance further. In this paper, we introduce analog network coding (ANC) to a simple two-user cooperative diversity network, which adopts amplify-and-forward (AF) mode and all nodes use multiple antennas. The impact of the number of antenna on the system achievable rate is investigated. And the bit error rate (BER) performances of the traditional relay cooperative network and the cooperative network based on analog network coding under different propagation conditions are discussed. The simulation results show that the performance of the traditional cooperative network has improved significantly due to the employ of network coding.
In this paper,the bit error rate(BER) performance of cooperative multiple input multiple output(MIMO) system is analyzed and two thresholds for decode-and-forward(DF) cooperative network are proposed.While the two thresholds are satisfied,the cooperative network may achieve a notable improvement of BER performance compared with the non-cooperative network.The analysis and simulation results show that the average BER of cooperation with the two thresholds is much lower than traditional cooperation,and the average BER of cooperation with only threshold one is almost the same as the former scheme and it is much easier to implement.
