基于IEEE802.16的OFDM系统中信道估计的新内插方法

The new interpolation technique for channel estimation in the OFDM system based on IEEE802.16

介绍了OFDM系统中两种基于导频的信道估计算法:最小均方误差(MMSE)算法和最小二乘(LS)算法。LS算法具有实现简单、收敛速度快等特点,很多实际的OFDM系统都采用了这种方法。在采用梳状导频进行信道估计的系统中,通常需要内插的方法来获取非导频位置的信道信息。因此针对非导频位置信道的线性内插方法进行了深入研究,提出了新的线性内插方法,即从幅度和相位角度实现内插,区别于传统的实部和虚部分别内插的算法,在某些信道环境下能够更好的恢复出非导频位置信道估计值。以基于IEEE802.16的OFDM系统为例,与传统的线性内插方法进行了比较。均方误差、误差矢量幅度以及误比特率的仿真结果表明,新方法估计的性能更忧。

The algorithms of channel estimation based on comb-type pilots in OFDM systems were introduced,including MMSE and LS estimation.The LS algorithm,which has low complexity and converges fast,had been used in many practical OFDM systems.The channel response between two pilots is commonly acquired by interpolation in systems,which address channel estimation based on comb-type pilots.Therefore the linear interpolation techniques were researched deeply in particular,besides,a new linear interpolation way from amplitude and phase was proposed,which was different from the traditional way through real part and imaginary part,it could recover the value of channel estimation better in not pilot position in some channel conditions.Then taking the OFDM system based on IEEE802.16 for example,it was compared with traditional method.The simulation of bit error ratio,error vector modulation and mean square error demonstrated that the new technique presented higher performance.