IEEE802.16e系统信道估计算法研究

Study on channel estimation for IEEE802.16e systems

针对IEEE802.16e系统下行链路的导频分配模式,提出了一种适用于IEEE802.16e系统下行链路的信道估计方法。该方法采用两个一维信道估计器的级联。首先在时域进行滤波,根据最近原则将前一个符号导频处的信道响应作为下一个符号相同位置子载波处的信道响应,从而得到梳状导频结构;其次在频域进行滤波,采用最大似然算法估计出所有子载波上的信道响应。车速60km/h和车速120km/h信道下的仿真结果表明,采用该信道估计方法可降低系统的误码率,提高高速移动环境下系统的性能。

Based on the downlink pilot arrangement of IEEES02.16e systems, a novel channel estimation algorithm is pro- posed. The algorithm adopts two cascaded one dimension （l-D） channel estimators. The first estimator filters in the time domain. According to the nearest rule, the channel response of the former pilot symbol is used as the channel response at the same pilot position in the next symbol, so that the pectination pilot structure is obtained. The second estimator, which filters in the frequency domain, acquires the channel responses at the whole sub-carriers by the maximum likeli-hood （ML） algorithm. The simulation results obtained under the channel models of vehicular 60km/h and 120km/h show that the proposed method improves the bit error rate （BER） performance of the systems under high-speed mobile situation.