多载波系统中自适应比特功率分配算法研究

本文提出了一种多载波系统中自适应功率和比特分配算法。该算法在低信噪比时基于最大化信道容量分配比特,基于最小化误码率分配功率;在高信噪比时采用Fischer算法进行比特功率分配。仿真结果表明,低信噪比时所提算法比Fisher算法性能好,高信噪比时和Fisher算法的性能一样好。因此,文中所提算法比Fisher算法更具有实际应用价值。仿真结果也表明了子载波数对系统性能的影响。

A Study of Adaptive Bit and Power Allocation in Multicarrier Systems

An adaptive bit and power allocation algorithm is proposed in this paper.This algorithm allocates bit and power based on maximizing the channel capacity and minimizing the bit error rate respectively during lower signal-to-noise-ration(SNR) and it is the same with the loading algorithm proposed by Fischer et al during higher SNR.Simulation results show that the proposed algorithm is better than Fischer's during lower SNR,and is the same with Fischer's during higher SNR,that is to say,the proposed algorithm is more useful.The results also show the effect of sub-channel numbers on system performance.