低复杂度无线OFDM自适应信道估计算法

提出了一种基于传输信道状态检测的低复杂度无线OFDM系统自适应信道估计算法,利用导频子载波在时频方向对当前信道状态进行统计检测,动态跟踪信道参数的变化特征,自适应选择当前条件下的最优内插滤波系数;同时简化传输信道先验统计信息求解,以此作为滤波系数选择的依据.仿真结果表明,在低复杂度条件下可以获知当前信道模型化参数近似统计信息,利用较少的计算资源就能获得较好的自适应性能;从而有效克服了二维Wiener滤波器实现复杂度高,以及传统信道估计按照最恶劣信道情况上限进行设计所导致的非匹配性估计性能损失.

Low-complexity Adaptive Channel Estimation Scheme for Wireless OFDM Communication Systems

The conventional channel estimator was designed to cope with the worst-case channel condition,thus performance degradation could be induced due to the imperfect channel estimator.An adaptive two dimensional interpolation filtering for channel estimation in OFDM systems with low computational complexity was proposed,which overcame the problem of high complexity of Wiener filter algorithm.Its main idea was to prestore sets of filter coefficients for different channel conditions in different wireless transmission environments.In order to select the near optimal prestored interpolation coefficients channel parameters detecting methods including maximum multipath delay and doppler frequency based on the time and frequency correlation functions were proposed.Simulation result shows that the scheme proposed can provide a compatible improvement to wireless OFDM receivers.