基于DFT的UWB-OFDM信道估计算法

在基于OFDM技术的UWB系统中,由于信号在无线信道中传输,多径现象使得信号幅度发生衰落,相位发生偏移,为了保证通信的可靠性和有效性,接收机采用信道估计方法来预知信道的传输特性,补偿信道对超宽带信号造成的影响。在直接DFT估计方法的基础上,提出一种加窗DFT信道估计算法,用汉宁窗在时域上对信道冲激响应进行处理,有效地抑制频域响应的频谱泄漏。理论分析和仿真结果都表明在没有增加信道估计复杂度的基础上,提出的信道估计方法性能优于直接DFT估计方法。

Analysis of DFT-Based Channel Estimation Algorithm for UWB-OFDM

In the UWB-OFDM communication system, as the signals are transmitted in the wireless channel, multi-path phenomenon results in signal fading and phase offset. In order to ensure the reliability and availability of the communication, channel estimation is necessary for receiver to understand the characteristics of the transmission channel exactly, then to compensate the influences of the channel to the signals. Based on direct DFT, a windowed DFT estimation algorithm is proposed. The hanning window is applied to channel impulse response to reduce the spectral leakage in the time domain. The channel information gained from the estimation is used for equalizing signals to reduce the influence of the multipath channel. Analysis and simulation results show that with low estimation complexity the proposed method performance is better than the direct DFT.