Study Of Semi-blind Channel Estimation Approach For MIMO SC-FDMA Systems

The two major characteristics of the wireless channel are multi-path and time-variant properties. For the performance of decoding and coherent demodulation, the receiver has to know the accurate knowledge of the channel. Therefore, the accuracy of channel estimation is of crucial importance to wireless system. Channel estimation methods can be divided into three categories: the blind method, the non-blind method and the semi-blind one as a combination of the first two methods. With a small number of training symbols, the semi-blind method optimizes the parameters of the tracking channel by using the statistics of the transmitted signals. The semi-blind channel estimation has been recently considered as a competitive method for the next generation mobile communications due to its reliability as well as using small channel resources.Due to its low peak-to-average power ratio, single carrier frequency division multiple access (SC-FDMA), a modified form of Orthogonal FDMA (OFDMA), has been adopted as the uplink multiple access scheme in the Long Term Evolution (LTE) of cellular systems by 3GPP. In this paper, a semi-blind channel estimation method is presented for multiple input multiple output (MIMO) SC-FDMA systems. The new method uses a training-based least squares (LS) criterion along with a blind constraint based on the linear prediction. Simulation results show that the proposed method consistently outperforms the LS method when the same pilots are used.