Performance of channel estimation schemes for multicarrier systems

This paper considers a multicarrier system performing burst transmission and discusses the channel estimation method, together with the estimation accuracy. In a multicarrier system such as OFDM, the channel state information of each subcarrier is estimated using a known signal, and then the signal is detected. Consequently, the accuracy of channel estimation has a large effect on transmission performance. Furthermore, in an MC-CDMA system in which OFDM is combined with code spreading in the frequency domain, the signal is also synthesized by using subcarriers in the receiver on the basis of the subchannel information. Thus, the signal quality after despreading depends greatly on the accuracy of channel estimation, and it is an important issue to establish a channel estimation method suited to a multicarrier system and to evaluate its accuracy. This paper considers channel estimation in the time domain based on correlation calculation for the known signal and channel estimation in the frequency domain using the FFT of the known signal. The accuracy of estimation is derived analytically, and a method of reducing the computational complexity is proposed. Finally, the receiver performance is derived quantitatively by computer simulation, assuming that these channel estimation procedures are applied, and the effects of these methods on the quality of the received signal are analyzed. © 2005 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 89(4): 10–21, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.20261