信道估計(jì)作為OFDM 中的一項(xiàng)關(guān)鍵技術(shù)，直接影響著OFDM 系統(tǒng)的性能。而現(xiàn)有
的最小二乘估計(jì)（LS）算法、最小均方誤差估計(jì)（MMSE）算法等都存在各自的不足。因此本文提出了一種稱為平均反饋（AF）的新算法，該算法利用兩個(gè)相鄰的OFDM 符號(hào)之間的關(guān)聯(lián)信息對(duì)LS 算法的估計(jì)結(jié)果進(jìn)行平均和反饋，以減少高斯白噪聲與子信道間干擾（ICI）對(duì)信道估計(jì)結(jié)果的影響。通過仿真證明，新算法改善了LS 算法的性能，尤其在低信噪比環(huán)境下的性能改進(jìn)明顯。
【關(guān)鍵詞】正交頻分復(fù)用 信道估計(jì) 最小二乘估計(jì)平均反饋算法
【Abstract】 Channel Estimation technique is one of the key techniques in OFDM and it directly affects the performance of the system. Some existing methods, such as LS method and MMSE method, having some obvious shortcomings respectively. So an improved method is proposed in this paper. The optimal method reduces the interfere of noise and ICI by using the related information between two adjacent OFDM symbols to feedback and average. At last, the simulation result demonstrates that, compare with original LS methods; new methods improve the BER performance, especially in the low SNR environment.
【Key words】 OFDM channel estimation least square(LS) average feedback (AF)