移动通信中继系统中减少反馈调度的算法研究

Reducing Feedback Scheduling Used in Relay System

对于多用户中继系统中上行反馈量过大的问题,研究提出了一种基于多门限减少反馈的半分布式调度算法.该算法在基站与中继分别设置反馈门限,依据在多门限假设下可以得到总反馈用户数表达式,进而算出多个门限值;又根据中断概率算得一个门限,将该门限值作为多门限的下限.将两种门限值相结合以限制用户反馈量.对AF(Amplify and Forward)协议下采用该算法的反馈用户数及系统容量等性能指标给出了理论推导.仿真结果表明,该算法可较单门限算法进一步地减少反馈量,并降低系统的反馈中断概率,增大了系统容量.

For the problem of excessive feedback in the uplink of multi-user relay system, one semi distributed scheduling method based on multi-threshold is proposed in this paper. Respectively set the feedback threshold at the base station and relay in this method. On one side, get the formula of total feedback users based on the multi-threshold assumption, and then calculate multi-thresholds from the formula~ on the other side, get a threshold according to outage probability, and this threshold is applied to be the minimized one in the algorithm. Combine two kinds of thresholds together to reduce feedback. This paper gives detailed theoretical derivation on performance index of the proposed algorithm, such as the feedback load and the system capacity, etc. The simulation results show that this algorithm reduces feedback load compared to the single threshold algorithm. Meanwhile, the outage probability has been reduced and the system capacity has been increased.