Research On MIMO Systems Detection Scheme Based On QSP

Based on the crossover and fusion of quantum and information theory, an emerging discipline called quantum information science was produced, which puts forward the quantum signal processing(QSP). Extending quantum mechanics and its related research topic to the wireless communication technology is a new direction of the future research and development of wireless communication technology. In wireless communication systems, multiple inputs multiple outputs(MIMO) is popular by improving the transmission rate and reliability in the limited frequency band resources. At present the most representative of the MIMO system is the vertical bell laboratories layered space-time(VBLAST) coding system proposed by Bell Laboratory. It is widely used due to its simple structure and high spectral efficiency. In order to solve the existing algorithms can not do well in balancing detection performance and algorithm complexity, a split-step maximum likelihood(ML) detection algorithm is proposed. And then combining the particular QSP method, a new kind of detection algorithm based on covariance shaping least-squares(CSLS) is proposed. The main contents are summarized as follows.(1) For the high complexity of ML detection algorithm in VBLAST system, a split-step ML detection algorithm is proposed. Successive interference cancellation and QR decomposition algorithm are combined together. And finite steps of maximum likelihood detection are used to improve the performance of each detection signal which reduced the error propagation. The complexity of this algorithm is greatly reduced as against the traditional ML algorithm. The proposed algorithm is simulated and compared with the conventional detection algorithms. Simulation results show that the proposed split-step ML algorithm is superior to QR and zero forcing algorithms on the BER performance especially in the multiple antennas and under the condition of high SNR.(2) With the key elements of quantum physics, the overall framework of QSP is presented and some key achievements of this framework are discussed, mainly includes: quantum measurement, quantum detection, QSP and subspace measurement. The exploration of radio baseband signal quantum mapping method has been carried on, and the preliminary quantum signal transmission model and the derivative MIMO signal detection scheme are put forward.(3) According to the classic quantum least-squares(LS) detection algorithms, the LS inner product shaping and minimum mean square error(MMSE) covariance shaping are deduced. And the CSLS estimation algorithm deduced at the same time. Applying this estimator in VBLAST detection, a detection algorithm based on CSLS is proposed. Theoretical derivation of this algorithm and the simulation experiment are done in detail. The simulation results show that the proposed algorithm can achieve VBLAST signal detection, and it is of superior detection performance in theory.