导频比和多普勒频移对OFDM系统影响的研究

参考无线多径信道中的COST-207信道模型,选取COST-207模型中的典型城市环境针对不同导频比与不同多普勒频移频率对基带OFDM通信系统性能的影响进行了仿真分析.从仿真结果得出使用块状导频形式的OFDM系统容易受多普勒频移与时间选择性信道变化的影响.同时当信噪比达到一定程度后,子载波间干扰是构成系统噪声的主要部分.而梳状导频虽然在性能上不如块状导频,但在对抗多普勒频移与时间选择性衰落信道方面相比块状导频具有一定的优势.

Simulation and analysis on the OFDM system effects of pilot ratio and Doppler frequency shift

This paper investigates the performance of Orthogonal Frequency Divided Multiplexing （OFDM） base band communication system in Rayleigh mulfipath channel environment, which is affected by different pilot ratios and different Doppler frequency shift referring to wireless multipath channel model COST-207. According to the simulation result, the block-based pilot is more likely to be influenced by the Doppler frequency shift and time-selective channel. When SNR reaches some certain level, ICI will be the main part of system noise. The performanee of comb-based pilot is less-competitive than block- based pilot, but it has some advantages when it comes to overcome Doppler frequency shift and time- selective channel fading.