A Multi-User Channel Estimation Method Based on Threshold Processing for the Downlink of TD-SCDMA

Because channel estimator proposed by B Steiner for TD-SCDMA system is mainly affected by additive noise,those methods using threshold processing is likely to filter out the paths containing strong information whereas the path with noise is falsely kept.Based on the characteristics that a specific user can receive the training sequences of all the downlink users,a multi-user channel estimation method based on threshold processing was proposed.By comparing the amplitude weighted values with a given value,the method firstly removed some channel estimation windows whose Signal Noise Ratio(SNR) were too small,then averaged the rest of the channel estimation windows,and finally,processed the averaged results with threshold processing method to suppress the channel response contributed by noise.Simulation results show that at the same bit error rate,the average SNR required in the proposed method is 1～4dB lower than that in the direct threshold processing method;When SNR is lower than 5dB,the proposed method has the same performance as the weighted-unit method with high complexity.