Applying V-BLAST detection algorithms into TDD-CDMA

Abstract

According to the similarity of the channel model of V-BLAST and TDD-CDMA, this paper proposes a scheme to apply the V-BLAST detection algorithms into TDD-CDMA. Generally, V-BLAST system is combined with OFDM, so the undergoing channel is flat. But the channel of TDD-CDMA is always frequency selective. Therefore, when the V-BLAST detection algorithms are applied into TDD-CDMA, the algorithms need to be modified. The proposed symbol by symbol scheme can apply the V-BLAST algorithms, which are MMSE-SIC (Minimum Mean Square Error-Successive Interference cancellation) and MMSE-QRD (Minimum Mean Square Error-QR Decomposition) in this paper, into TDD-CDMA. The experiment of paper which compares the symbol by symbol scheme of MMSE-BDFE (minimum mean square error-block decision feedback equalization), MMSE-SIC and MMSE-QRD shows that MMSE-SIC has better performance than the others, and MMSE-BDFE and MMSE-QRD have the similar performance. MMSE-SIC has highest complexity and MMSE-QRD has lowest complexity. The proposed algorithms can be applied in the MIMO receiver of HSDPA+ in TD-SCDMA.