基于截短ARQ协议的协作分集系统吞吐量研究

Throughput Study of Cooperative Diversity System Based on Truncated ARQ Protocol

研究协作分集通信系统的跨层设计使系统吞吐量最大化.首先推导基于截短ARQ协议的协作分集和两跳系统的吞吐量理论表达式,揭示数据包长度和调制方式对系统吞吐量的影响,在此基础上用自适应技术优化系统性能,采用连续二维优化求出了吞吐量的最大值,进而提出了实用的二维离散吞吐量优化算法,该算法的优化结果与吞吐量最大值相差很小,最后提出了计算量更小的一维离散优化算法,且其吞吐量性能损失也很小.

In this paper, the throughput of a cooperative diversity communication system based on truncated ARQ protocol is studied. The theoretical throughput expressions of cooperative diversity and two-hop systems are derived.According to the expressions, throughput is affected by the MAC layer parameter data packet length L and physical layer parameter modulation level b, so cross-layer design can be used for throughput optimization. By assuming that L and b are continuous variables, the maximum throughput is evaluated by two-dimension （2-D） continuous optimization algorithms. Then a 2-D discrete optimization algorithm is proposed to find the maximum throughput, which is practical for applications.Furthermore, with the knowledge of signal-to-noise ratio （SNR） information,the 2-D algorithm is simplified into a 1-D algorithm. The 1-D discrete algorithm has only a little performance loss compared with the 2-D algorithm.