一种对抗强单音干扰的短波OFDM信道均衡机制

短波信道使用的频率范围较窄,频谱资源十分紧张,会出现大量的强单音干扰。因此针对存在强单音干扰的短波信道,提出了一种高效、简洁的信道均衡机制,该机制通过干扰抑制、信道估计、维纳插值等算法的有机结合,首先对接收到的信息序列硬判决,基于干扰门限对大幅度干扰进行抑制;其次,根据最小平方准则估计出导频子载波处信道传输函数;最后使用二维维纳插值工具,利用导频符号之间的相关性,计算出数据子载波处信道传输函数。并以强单音干扰下短波正交频分复用(OFDM)系统为例,对所提出的机制进行了仿真验证,结果表明,与其它均衡机制比较,所提出机制降低了接收端符号误码率,有效地提高了通信可靠性。

A short-wave OFDM channel equalization mechanism against strong single-frequency interference

The frequency range of short-wave channel is quite narrow and the frequency spectrum resource is extreme tense. There are lots of strong single-frequency interferences. So focused on the short-wave channel with existing strong single-frequency interference, we proposed an efficient and simple channel equalization mechanism. This mechanism is based on the interference suppression, channel estimation and wiener interpolation. Firstly, receiver makes hard decision based on information-sequence and suppress interference by interference threshold. Secondly, according to the least square criterion, receiver estimates the pilot subcarrier channel transfer function. Finally, using 2-D wiener interpolation tool, receiver calculates the data subcarrier channel transfer function by the pilot symbol correlation. Moreover, we simulated the short-wave OFDM system with strong single-frequency interference. Through the simulation, the proposed mechanism, compared with other equalization mechanisms, cannot only reduce the receiving symbol error rate but also improve the communication reliability effectively.