Channel estimation is one of the key techniques for OFDM systems. Compared with the differential demodulationn, coherent demodulation with accurate channel information can achieve 3-4 dB gain in signal-to-noise ratio (SNR).

• 信道估计是OFDM系统中的关键技术之一,利用信道信息的相干解调系统与不利用信道信息的差分解调系统相比,在信噪比(signal-to-noise ratio,SNR)上可以有3 dB以上的性能提高。