中文摘要：

针对低压电力线通信信道的实际条件，探讨了相应的自适应正交频分（OFDM）系统模型。提出将具有全局优化进化能力的粒子群算法用于多用户自适应OFDM系统的比特、功率分配，能够提斋蒴谱利用率，降低系统发射功率。采用改进的粒子群算法，增大算法后期粒子位置的改变量，克服算法容易出现早熟收敛问题。在典型电力线信道环境的仿真分析表明，相比于已有算法，该算法在保证系统通信性能的同时，提高了运算速度。

英文摘要：

According to the actual condition of the Low Voltage Power Line Communication （PLC） channel, the adaptive OFDM system model is analyzed. Utilizing Particle Swarm Optimizer （PSO） algorithm which has overall optimization and evolution function to the multi-user adaptive OFDM system in bit and power allocation, can increase the spectrum usage rate and reduce the transmission power of the system. An improved PSO algorithm has been proposed to avoid the premature convergence by increasing the diversity of the particle in the later phase of traditional PSO algorithm. The algorithm is tested in the typical power line channel environment, and the simulation result indicates that compared with the traditional algorithm, it can ensure system communication performance and accelerate the operation speed synchronously.