Design of 2-D channel estimation filters for OFDM systems

The performance of channel estimation can be improved by employing a channel estimation filter (CEF) that can adjust its bandwidth in response to the channel condition. For coherent OFDM receiver, we consider the use of two-dimensional (2-D) moving average (MA) FIR filter with a linear interpolation filter as the CEF that can provide good performance without requiring large implementation complexity. The optimum tap size of 2-D MA FIR CEF is analytically determined in terms of the pilot spacing, the channel spectrum and pilot signal to interference power ratio. The performance of the proposed channel estimator is evaluated by computer simulation.