Impulse burst position detection and channel estimation schemes for OFDM systems

Abstract

A new method for compensating the effects of impulse noise in OFDM systems has been presented by Rinne, Henriksson and Hazmi (see Proc. 7th International OFDM Workshop, Hamburg. Germany, p.183-187, Sept. 2002). It is shown that in the AWGN case, the method can effectively cancel the impulse noise. However in the time-frequency selective channel further measures are needed. The purpose of this paper is to present an enhanced channel estimation scheme for the standard method to overcome its sensitivity to the time frequency selective channel estimates. The scheme uses the impulse free pilots to estimate the corrupted ones. Three different alternatives are discussed. Their performances in mean squared error (MSE) versus Doppler frequency are studied analytically. Bit error rate ratio (BER) simulations results are given, in the cases of SFN hilly terrain static and mobile channels. Additionally, results on simple practical impulse burst position detection method are also presented.