Equivalently blind time-domain channel estimation for MC-CDMA system over frequency-selective fading channels in multiuser scenario

Many blind channel estimation methods have been proposed for direct sequence (DS) CDMA systems, so we can certainly use them to estimate the finite impulse response (FIR) channel for the multicarrier code division multiple access (MC-CDMA) system. In this paper, we interpret the MC-CDMA system as an equivalently DS-CDMA system with specific spreading codes. Then, an equivalently blind time-domain channel estimator is derived for the MC-CDMA uplink, which is based on second-order statistics of the received data. Because there is no need of a large amount of sampling data, this method is greatly suitable for the fast time varying wireless channels. By exploiting singular value decomposition (SVD) and the finite alphabet property of transmitted symbols, the time-domain channel impulse response (CIR) for the MC-CDMA can be accurately identified. Computer simulations illustrate both the validity and the overall performance of the proposed estimator.