Adaptive prediction iterative channel estimation for MC-CDMA signal reception in a frequency selective fading channel

摘要

An adaptive prediction iterative channel estimation is proposed for the MC-CDMA signal reception in a frequency selective fading channel. Adaptive prediction filtering is incorporated into iterative channel estimation process and the filter tap coefficients are adaptively updated according to changes in the propagation environment. For channel estimation, the pilot MC-CDMA symbol is periodically time-multiplexed in the sequence of transmitting MC-CDMA data symbols. The first stage applies one of two channel estimation methods, depending on the data symbol position. For the coherent detection of N{sub}c/SF data symbols (N{sub}c and SF representing the number of subcarriers and spreading factor; respectively) placed next to pilot MC-CDMA symbol, frequency-domain adaptive prediction filtering using pilot MC-CDMA symbol is applied to obtain the first stage channel gain estimates in the frequency domain. For the coherent detection of other data symbols, the channel gain estimates obtained at the last iteration stage in the detection of previous N{sub}c/SF data symbols are utilized as the first stage channel gain estimates. The succeeding iteration stages applies decision feedback, reverse modulation and frequency-domain adaptive prediction filtering for re-channel estimation. The improvement in the bit error rate (BER) performance in a frequency selective Rayleigh fading channel is elucidated by computer simulation.