Signal detection and interference cancellation for TD-SCDMA downlink in fast time-varying environment [3GPP applications]

In TD-SCDMA downlinks, one favorable receiver structure is the single user detection, based on block linear equalization (SUD-BLE), implemented by fast Fourier transform (FFT). In this paper, we first analyze the interference involved with the sub-block processing proposed in (I. Held et al, Proc. China Wireless Congress, 2002) and then propose a new sub-block processing receiver for fast time-varying channels. The proposed receiver consists of two stages. In the first stage, the entire data chip block is first partitioned into overlapping sub-blocks and they are then equalized and despread. We then artificially generate the interference caused by adjacent blocks and unwanted chip interference within the same sub-block and subtract the interference from the received data signal. Then a second sub-block processing is performed to detect the transmitted symbols. Simulation results show that the proposed receiver provides significant performance improvement as compared with the conventional sub-block processing previously proposed.