A high efficiency channel estimation and equalisation strategy for a broadband COFDM system

COFDM is a channel coding and modulation scheme that mitigates the adverse effects of time-varying, frequency-selective fading by using multi-carrier modulation combined with time- and frequency-domain interleaving and forward error correcting coding (FEC). COFDM effectively transforms the time-domain equalisation problem of conventional single carrier systems into the frequency domain. This paper examines the performance of an efficient feedback channel estimation and equalisation algorithm for a 25 Mb/s COFDM-QAM system in a frequency-selective multipath channel. In particular, the effect of the COFDM block length relative to the coherence time of the channel is discussed.