速率比例公平下多用户OFDM系统的自适应资源分配

在多用户正交频分复用(MU-OFDM)系统中,考虑各个用户之间具有比例数据传输速率限制条件下的一种公平的自适应资源分配方案的最优算法计算量巨大,为此,提出了一种将子信道分配和功率分配相分离的次优算法.首先,在假设相同功率分配的情况下进行子信道的分配,然后在保持一定比例公平条件下使总容量最大时进行最优功率分配.对该算法的仿真表明,在用户数为2、子信道数为10的系统中,所提算法的容量性能接近最优算法,而计算量由指数增长变为线性增长.所提资源分配算法的总容量比以前的算法在用户间的分配更公平也更灵活.

Adaptive Resource Allocation with Proportional Rate Constraints in MU-OFDM Systems

The computation of the adaptive resource allocation with proportional data rate constraint s in multiuser orthogonal frequency division multiplexing (MU OFDM ) system is large when considering the fairness among the users. To avoid the ex treme computation comp lex of the optimal solution, a low complexity suboptimal algorithm is proposed in which subchannel allocation and power allocation are separated. In the propos ed algo rithm, subchannel allocation is first performed by assuming an identical power allocation. Then an optimal power allocation algorithm is carried out to maximi ze the sum capacity while maintaining proportional fairness. The simulation resu lt of the proposed algorithm shows that approximate performance of the optimal capacity can be achieved in a two user ten subchannel system, while t he compl ex ity is reduced from exponential to linear. The sum capacity of the pr oposed resource allocation algorithm is more faire and flexible among users tha n that of the previous.