多用户电力线通信自适应OFDM系统中的资源分配与交换优化

自适应正交频分复用(OFDM)是一种实现电力线多用户高速数据通信的技术，资源动态分配是这一技术的重要组成部分。文章针对电力线通信的限制条件，探讨了在最大总功率、各用户要求最小速率、各子载波分配最大功率和比特数的约束下，多用户在多子载波上自适应比特和功率分配的数学模型，提出一种新的速率自适应动态资源分配算法，其实现分为4个相互联系的阶段，依次是确定工作子载波、单用户资源分配、子载波和功率交换、比特交换和功率调整。在典型电力线信道环境下的仿真结果表明，该算法比已有的多用户频谱分配优化算法性能更优，能更好地满足多用户资源分配模型的目标要求。

Resource Allocation and Swap Optimization of Adaptive OFDM System for Multi-User Power-Line Communication

Adaptive orthogonal frequency division multiplex (OFDM) is such a technology to implement multiuser high-speed data communication based on power-line, and resource dynamic allocation is an important component element of OFDM. Considering the restraint conditions in power-line communication, a mathematical model of adaptive bit and power allocation on multi-sub-carrier for multiuser under the conditions of maximum total power, required minimum rate of users, allocated maximum power and bits of each sub-carrier is researched, and a new resource dynamic allocation algorithm with rate adaptation is proposed. The implementation of the proposed algorithm is divided into four interdependent stages in which the first one is to determine working sub-carriers, and in turn the others are the resource allocation for single user, the swap of sub-carrier and power as well as the bit swap and power adjustment. Simulation results of the proposed algorithm in typical environment of power-line communication channels show that the proposed algorithm possesses better performance than that of existing multiuser frequency spectrum allocation optimization algorithms and can meet the requirement in multiuser resource dynamic allocation model better.