Channel estimator and equalizer for OFDM systems

Abstract

An initial estimate of the channel response in an OFDM system is obtained. An implied ICI is calculated using an estimated frequency offset, and used to adjust output from an FFT in an OFDM receiver. The channel response is iteratively estimated one or more times using this procedure. Data equalization is performed using the iteratively calculated channel estimate. The implied ICI is constructed, and the output from the FFT in the OFDM receiver is adjusted to determine an estimate of transmitted data. A simplified implementation of iterative channel estimation and data equalization involves adjusting single tap equalizer values to provide an acceptable estimate of incoming data. The simplified iterative channel equalizer can be implemented using a FIR filter.