基于判决反馈的正交频分复用低压电力线通信信道估计的研究

正交频分复用技术以其多种优势成为低压电力线宽带通信的最佳选择,信道估计是正交频分复用系统的关键问题之一.该文分析了低压电力线信道特性,利用信道慢时变的特点提出一种适合于电力线信道的判决反馈信道估计方法.这种方法使用前一个正交频分复用符号计算得到的信道估计值去均衡下一个接收符号,形成一个集判决,反馈,信道估计为一体的回路.它不需要加入导频符号,能够进行连续信道估计,大大提高了系统传输效率.将该信道估计方法用于电力线通信仿真系统中,取得了较好的效果.

CHANNEL ESTIMATION BASED ON DECISION FEEDBACK FOR OFDM SYSTEM IN LOW-VOLTAGE POWER LINE COMMUNICATION

Due to many advantages of Orthogonal Frequency Division Multiplexing technique, it becomes the best choice for low-voltage power line broadband communication. Channel estimation is one of the key problems in Orthogonal Frequency Division Multiplexing system. The low-voltage power line channel properties are analyzed in this paper and a decision feedback channel estimation method is proposed on condition of slow time-variant of channel. In this method, the pre-channel estimation value is used to equalize the next receiving symbol, so a loop including decision, feedback and channel estimation is formed. No pilot symbols are needed and consecutive estimation can be made, which improves transmission efficiency. This method is applied to the power line communication simulation system, which gels a good performance.