一种短波OFDM系统窄带干扰消除技术

A Scheme of Narrowband Interference Cancellation in SW OFDM System

鉴于短波OFDM系统的频带较宽,很容易受到传统短波电台窄带的干扰,且当干扰严重时性能恶化的现状,提出了一种短波OFDM系统窄带干扰消除技术.该技术是以自适应子载波为基础,在接收端估计窄带干扰的位置和幅度等信息,然后将受窄带干扰影响的子载波关闭,并通过反馈信道将关闭子载波的信息反馈至发送端,使之在后续的通信过程中关闭这部分子载波.仿真结果表明:在信道估计准确的前提下,采用此消除技术的系统性能指标与无窄带干扰系统的误码率性能指标基本一致,对改善短波OFDM通信系统性能具有实际意义.

Considering that the frequency band of OFDM system is wider, the system is liable to be interfered by conventional SW radios and its performance can be deteriorated due to sever interference, this paper puts forward a scheme of narrowband interference cancellation in SW OFDM. In this scheme, based on an adaptive sub-carrier, the information on location and amplitude ofnarrowband interference is estimated and then the sub-carrier interfered by the narrowband is closed while the information o＇n sub-carrier closing is sent back to the transmitter via the feedback channel, thus closing the sub-carrier in the following process of communion. Simulation results show that there is no big difference between the performance index BER of the system using the cancellation scheme and that of the system without narrowband interference, which is of significance of improving the performance of OFDM communication system.