Research On Space-time Processing For CDMA System With Antenna Array

Space-time processing technique combines time domain signal processing and spatial signal processing. It can utilize fully the space-time channel characteristic, repair limits of the time domain signal processing and spatial signal processing, and enhance the system capability, overlay area and transmission rate. Space-time processing for CDMA with antenna array is investigated in this paper, which includes space-time channel estimation, beamforming technique, 2D-RAKE receiver, multiuser detection, space-time multiuser detection and joint estimation. The main contents are as follows.Blind joint angle and delay estimation method based on parallel factor technique is investigated in section 3. A blind joint angle and delay estimation method based on trilinear alternating least square in uniform linear array (TALS-LJADE) is presented, and a blind joint angle and delay estimation method based on complex parallel factor in uniform linear array (COMFAC-LJADE) is given to improve theTALS-LJADE convergence performance. A blind joint angle and delay estimation method based on trilinear alternating least square technique in uniform circular array (TALS-CJADE) is also presented in section 3, and a blind joint angle and delay estimation method based on complex parallel factor in uniform circular array (COMFAC-CJADE) is given to improve the TALS-CJADE convergence performance. The simulation results reveal that TALS-LJADE and TALS-CJADE algorithms have the better estimation performance for delay and DOA, and work well in the overload system. The algorithms have blind and robust characteristic, which does not need the channel impulse response. COMFAC-LJADE and COMFAC-CJADE algorithms have the better estimation performance for delay and DOA, and better convergence.Section 4 researches on pilot symbol aided space-time 2D RAKE receiver in rayleigh fading channel. Two kinds of 2D-RAKE receivers are proposed, one is the interference zeros force 2D-RAKE receiver (ZF-2DRAKE). Simulation results reveal ZF-2DRAKE has the better performance than the conventional 2D-RAKE receiver. The other is time-space 2D-RAKE receiver based on space-time channel estimation (SPCE-2DRAKE). Simulation results reveal that this algorithm has the better performance under the different Doppler frequency. The performances of these space-time 2D-RAKE receivers are analyzed. An adaptive channel estimation method based on weighed least squares (AWLS) is proposed, and this method can meet the high speed, lower speed, middle speed and changing speed conditions. Simulation results reveal that AWLS method can track and estimate channel parameter well. A scheme which combines TALS-LJADE algorithm and ZF-2DRAKE is proposed. This scheme uses TALS-LJADE algorithm to estimate the delay and DOA, and then employs ZF-2DRAKE receiver. Simulation results reveal that this scheme has the better performance. A scheme which combines TALS-LJADE algorithm and SPCE-2DRAKE is proposed. This scheme uses TALS-LJADE algorithm to estimate the delay, and then employs SPCE-2DRAKE receiver to detect data. Simulation results reveal that this scheme has the better performance.Wavelet transform / wavelet packet transform based adaptive multiuser detection algorithm is presented in section 5. Theoretical analysis and simulations demonstrate that wavelet transform based adaptive multiuser detection algorithm converges faster than the conventional adaptive multiuser detection. Wavelet packet transform based adaptive multiuser detection algorithm converges faster than wavelet transform based adaptive multiuser detection algorithm. They also have the better performance. Simulation results also reveal that the algorithm convergence relates to wavelet base and decomposition...