针对无线信道的有限冲激响应及其全零点特性,本文设计了一种基于零点消除的无线正交频分复用(OFDM)系统信道缩短均衡器,该均衡器利用零点消除的方式有效地缩短信道时延扩展长度,并采用反馈滤波器的形式来实现无限冲激响应滤波器,该方案不仅降低了信道缩短均衡器算法的复杂度,而且也大大简化了无线OFDM系统的设计与实现.仿真结果验证了上述方案和算法的有效性.
Cyclic Prefix(CP) is inserted between Orthogonal Frequency Division Multiplexing(OFDM) transmitted blocks to combat multipath,provided that the channel delay spread is shorter than the length of CP.If this condition is not met,an additional Channel Shortening Equalizer(CSE) is required to shorten the channel to the desired length.A novel CSE for a wireless OFDM system is proposed.The CSE takes advantage of the characteristic of a wireless channel,which represents as an all zero system,and eliminates the zeros to effectively reduce the length of channel impulse response.Using feedback filters with low complexity to implement the CSE,the proposed equalizer simplifies OFDM wireless receiver.The Simulation results show the validity of the proposed equalizer.