OFDM transmission with receiver windowing for improved interference rejection

Traditional orthogonal frequency division multiplexing (OFDM) offers only highly limited protection against narrowband interference. More specifically, any interferer whose frequency does not coincide with one of the subcarrier frequencies will spill its energy over a wide range of subchannels due to the strong side lobes inherent to ordinary discrete Fourier transform (DFT). In this paper, a receiver windowed OFDM system for better interference rejection is described. Applying a window function in the receiver will constrain the interferer energy to only a few bins, independently of its frequency, but will also affect the useful signal. To unravel the windowing effect on the data symbols, a proper pre-distortion structure is introduced in the transmitter. Simulation results are given to illustrate the performance of the proposed approach.