Wide Linear Detection Technology. Distribution Of Mimo Signals

Multiple-input multiple-output (MIMO) is the framework of the next generation broadband wireless communication system. As the distributed wireless system communication becomes a tendency of future public wireless access, the organic combination of Distributed Antenna and MIMO, termed as DA-MIMO, has become the hotspot of MIMO wireless communications research. The signal detection is one of the key techniques in the field of DA-MIMO system.We firstly review the history of MIMO and the tendency of distributed antenna architecture. Then base on the survey and analysis of MIMO detection and widely linear (WL) detection technique, the thesis of this paper is established.In Chapter 2 of this paper, the basic channel models of centralized antenna MIMO (CA-MIMO) system and DA-MIMO system are presented and some assumptions are made. Compared those models, we clarify the essential of studying to detect DA-MIMO signals.So far, there is not much research on the signal detection of DA-MIMO system, and the general frequency selective channel is not taken into consideration. In Chapter 3 of this dissertation, the coherent signal detection algorithms for DA-MIMO system under both flat fading and frequency selective fading channels are derived. And the analysis of the factors which affect the performance of the detection algorithms is also illustrated through computer simulations.Though maximum likelihood detection (MLD) can obtain optimum detection performance in MIMO communication systems, the ergodic search increases the complexity exponentially with the number of the antennas, which lead to implemental difficulty. Therefore, to find the suboptimum detection schemes which have low complexity as well as good performance close to MLD is the main problem of MIMO signal detection. In general, many suboptimum strategies are the tradeoff between complexity and detection performance. For instance, linear detection has the advantage of analytical considerations and engineer implement, and poor detection performance. While non-linear detection has complementary characteristics. WL detection technique, a new technique arising from modern signal processing area, is embedded with both advantages. It is a joint detection scheme utilizing received signals and their corresponding complex conjugate ones, which brings significant performance gain. This paper discusses the possibility of applying this technique to detect MIMO signals.Chapter 4 introduces the fundamental knowledge of WL detection firstly. Then we focus on decision feedback equalization (DFE) algorithm which is widely used in MIMO signal detection. Subsequently, a minimum mean squared error (MMSE) detector based on WL detection combined with the decision feedback strategy for CA-MIMO is derived. Meanwhile, the issue that how to use WL detection in DA-MIMO system is discussed and a solved project is also presented. Some preliminary computer simulations for some DA-MIMO detection algorithms appeared...