Research Of Detection Based Cooperative MIMO And Iterative Processing

Multi-Input Multi-Output (MIMO) technique has attracted great interest due to its high spectra efficiency and transmission capacity in broadband wireless communications. The signal detection in MIMO wireless communication systems, called MIMO detection, is a key problem in MIMO system-related research that can never be bypassed. This dissertation mainly researches on the key techniques of MIMO detection:1) Tradeoff detection algorithms with less computational complexity. The fundamental MIMO detection algorithms can be divided into two types, one with best performance and the other with tradeoff performance. ML (Maximum-likelihood) algorithm is regarded as the best performance algorithm, which has one disadvantage of high computational complexity. Searching for the tradeoff detection algorithms with less computational complexity is one goal of our research. The detection algorithms of Sphere Decoding (SD), Semi-Definite Relaxation (SDR), Probabilistic Data Association (PDA) and the Ordered Successive Interference Cancellation (OSIC) are regarded as main tradeoff detection algorithms and are researched in this dissertation.2) Iterative joint detection and decoding algorithm (IJDD). In the traditional wireless communication systems, all the modules of the receiver just transmit the information in a straightly forward direction, which will result in losing the soft information and reducing the system performance. The IJDD algorithm, derived from the Turbo coding, takes advantage of the soft information of detector and decoder and enhances the performance by iterative processing. Shown in the simulation results, the system can receive high performance by several iterations processing with IJDD algorithm.3) Detection based cooperative MIMO and iterative processing. The ICI (inter-cell interference) is one of the important problems in the multi-cell network communication system and badly affects the performance of the system. To mitigate the ICI, how to design an effectively detection algorithm is one of key tasks of MIMO detection research. This dissertation proposes a multi-cell multi-user detection (McMuD) algorithm based cooperative MIMO and iterative processing. The ICI will be viewed as usefull signal and be detected by McMuD. After information exchanging between the neighboring base stations and information combining in the local stations, the McMuD will obtain high diversity gains. If not to consider the complexity, further iterative processing of McMuD is a good way to increase the performance of the System.