A Sequential Blind Channel Estimation Technique for OFDM Systems

摘要: A sequential blind channel estimation technique for OFDM systems is proposed. The method takes advantage of the simple frequency domain representation of the received signal in an OFDM system, and uses a suboptimal trellis search technique to estimate the channel's frequency response independently at each frequency bin. The phase uncertainty of the channel estimate, which is inherent in any blind channel estimation technique due to the constellation symmetry, is removed utilizing the frequency correlation among subchannels and the existence of transmitted pilots at specific frequency bins. Simulation results for the HIPERLAN/2 system indicate that the proposed technique is a potential method to obtain channel estimates without transmitting preamble sequences to retrain the receiver.