针对OFDM解码转发中继系统中的速率最大化问题,提出了一种基于多中继转发的资源分配算法。在该算法中,同一子载波能够被多个中继转发,并且在第二时隙,基站能够利用未被中继占用的子载波传输额外信息。为了降低计算复杂度,算法首先确定信息传输模式及中继模式下每个子载波的最优转发中继集合,然后通过将原始优化问题转化为对偶问题求解,实现了子载波配对与功率分配的联合优化。仿真结果表明,所提算法能使系统获得更高的系统容量。
For the rate maximization problem in OFDM decode-and-forward relay system, a resource allocation algorithm based on the multi-relay forwarding was proposed. In the algorithm, the same subcarrier could be forwarded by multiple relays, and the base station could use the subcarriers that are not occupied by relays to transmit new symbols in the second phase. To reduce the computational complexity, the information transmission mode and the optimal relay set that assisting the transmission under relay mode were determined first, then the original problem was transformed into a dual problem to achieve the joint optimization solution of subcarrier-pairing and power allocation. Simulation results show that the proposed algorithm can achieve a higher system capacity.