摘要
从最小二乘和最小均方误差两种估计准则出发 ,结合 OFDM多载波并行传输中符号时间长度大于信道冲激响应持续时间的特点 ,在块状和梳状导频图案下 ,导出了时域和频域的信道估计算法。最后采用广义平稳非相关散射假设下的多径时变瑞利衰落信道模型 ,对各个算法进行了仿真 ,比较了不同导频图案下各算法对系统误符号率的影响 ,分析结果表明 ,当导频数大于以采样间隔为量度的等效信道长度时 ,时域估计比频域估计精度更高 ;当导频数目小于等效长度时 ,最小均方估计优于最小二乘估计。
We investigate channel estimation with LS (least square)and MMSE(minimum mean squared error) estimation criterion combined with OFDM multicarriers transmission′s property that the length of channel impulse response is shorter than the length of OFDM symbol. Blocktypeand combtype arrangement pilotbased channel estimation is considerd here.The channel is restored utilizing variant algorithms from the view of timedomain and frequencydomain . We simulate all the aigorithms and analysis their effect to system′s SER in OFDM system at last,The channel model is timevaring multipath Rayleighfading model under the WSSUS(Widesense stationary uncorrelated scatterring) assumption.The result showed that when the number of pilots is larger than the channel length scaled by system′s sample interval,Timedomain estimation is better than frequencydomain estimation,Otherwise MMSE estimation is better than LS estimation.
出处
《现代电子技术》
2003年第21期85-88,共4页
Modern Electronics Technique
