OFDM系统的功率和比特分配算法

OFDM(正交频分复用)是高速无线数据通信系统最有力的候选技术之一。在OFDM系统中,能够根据各个信道的衰减对各载波的发送功率和传输的比特数进行动态分配,从而使系统性能达到最佳。首先介绍了功率和比特分配的最优算法、贪婪算法,并针对贪婪算法迭代次数多的不足,提出了一种改进的贪婪算法。该算法通过修改迭代过程的初始条件,大大简化了贪婪算法的计算复杂度。仿真结果表明,改进的贪婪算法能够在保持发送比特总数不变的同时有效减少迭代的次数。

Power and Bit Allocation Algorithm for OFDM Systems

OFDM is one of the most prospective alternative techniques in high-speed wireless communication system.According to attenuation of sub-channels,transmitted power and number of bits of every sub-carrier can be allocated dynamically in OFDM system.So it achieves optimal system performance.In this paper,we introduce greedy algorithm firstly.Then,considering complexity of greedy algorithm,this paper proposes a modified greedy algorithm.By modifying initial condition,the modified algorithm reduces computational complexity.Simulation result shows that the proposed algorithm achieves close to optimal performance at significantly lower computational cost.