基于中继OFDM系统的成比例公平分配算法

Resource Allocation in Relay-Based OFDM Networks with Proportional Fairness

为了满足无线蜂窝小区内不同用户的业务需求,针对下行正交频分复用中继系统,提出一种基于成比例公平约束的资源分配方案,其主要包括基站与中继处的子载波和功率分配,并在子载波分配过程中提出2种算法.其中,严格的速率成比例公平算法以尽可能满足速率成比例公平为目标,将子载波优先分配给比例公平性最差的用户;松弛的子载波成比例公平算法将速率成比例松弛为子载波成比例,避免了信道较差的用户占用大量子载波.子载波分配结束后,根据子载波分配策略进行注水功率分配.仿真结果表明,2种算法均能够较好地满足成比例公平约束,且与传统无中继的资源分配算法相比,明显提高了系统吞吐量.

A new scheme was proposed which adaptively allocates the resource in the downlink scenario of a cellular cooperative frequency-division multiplexing（OFDM） networks.The allocation scheme mainly contains the subcarrier and power allocation both in base station and relay nodes.Two algorithms,strict rate proportional fairness and relaxed subcarrier proportional fairness,for subcarrier allocation were proposed.The first one aims to achieve perfect rate proportional among users,allocates the best subcarrier to the user with worst rate proportional fairness;the second one relaxes the rate proportional fairness into subcarrier proportional fairness so that it can avoid too many subcarriers being allocated to the user with bad channel gains.After the subcarrier allocation,power allocation based on water-filling algorithm was employed to improve the throughput.The simulation results and analysis show that,both of the proposed algorithms can substantially increase the throughput,and achieve a fine proportional fairness.