OFDM系统中的快速发射功率分配算法

针对在限定传输速率和误码率的情况下最小化OFDM系统发射功率问题,提出了一种基于灌水原理的次最优快速算法。算法利用灌水水平和系统传输速率之间的关系求出高效的灌水水平粗搜索方法,然后用二分法求解出所需的灌水水平。当信道发生变化时,该算法可以快速地确定出新灌水水平所处的区间,从而实现对时变信道进行快速跟踪。仿真结果表明该算法收敛速度较快,适合应用于信道随时间变化的OFDM通信系统中。

Quick transmit power allocation algorithm for OFDM systems

To investigate the problem of minimizing transmits power in OFDM systems under the constraints of data rate and bit error rate,a sub-optimal computationally efficient algorithm based on the water-filling theory is proposed.By exploiting the relation between the water-filling level and the system data rate,an efficient searching method for coarse water-filling level is derived with the aid of the proposed algorithm,then the required water-filling level is determined by the dichotomy method.When channel state changes,the proposed algorithm can work out a small domain of the required water-filling level based on the latest allocation and then tracks the channel quickly.Simulation results show that the proposed algorithm converges quickly and it is suitable for time varying scenarios in OFDM systems.