Abstract: A theoretic analysis is made of the generalized channel of a wireless OFDM system, in which the FFT of the OFDM receiver is considered as a part of the generalized channel. It is proved that the output of the subchannel of the wireless OFDM system generalized channel and its nonlinear estimation are subject to the Bussgang procedure. Thus, a blind adaptive algorithm, LMS-Bussgang, is proposed for blind channel estimation. Meanwhile, a novel amelioration scheme is presented for accelerating the convergence of the algorithm and preventing error propagation, thus avoiding the degradation of efficient transmission rate and transmission delay due to periodical retransmission of pilot signal in systems with coherent detection. Both theoretic derivation and simulation results show that the algorithm is robust, less complex, and suboptimal.

Key words: OFDM, Bussgang procedure, blind channel identification, IBI, ISI