Abstract
Although multi-carrier code division multiple access (MC-CDMA) is highly promising for high-capacity wireless local communications, the conventional channel estimation with coherent detection methods cannot provide accurate channel information for equalization design as the fading rate (Doppler Spread) of the channel increases. This work presents a frequency-domain channel estimation method, which is also capable of estimating the statistic properties of channel estimation error of MC-CDMA in Rayleigh fading channel.The statistic properties of channel estimation error are useful for repairing in robust equalization design and can be estimated by using the system dynamic via Kalman filter technique in frequency domain.Following channel estimation, a subcarrier channel-tracking algorithm combined with enhanced MMSE receiver is used for robust equalization design with consideration of channel estimation error to prevent the severe error propagation under fast fading channel and interference.The performance analysis considering the effect of channel-estimation error is derived. Simulation results indicate that the proposed channel estimation can track the channel fluctuation well and the proposed enhanced MMSE method can achieve more robust equalization of MC-CDMA communication systems under the multipath Rayleigh fading channel and narrowband interferences.