Space-Time Code Multi-User Detection Algorithms Research

As next generation wireless communication system integrated with internet and multi-media application, the demand for high speed rate data transmitting services is increasing. This leads to much requirements of broad band. Because the wireless frequency is finite, high speed rate communications can only be realized by efficient signal processing technologies.Recently the researches on information theory show that Multi-Input Multi-Output (MIMO) system can dramatically increase wireless channel capacity. And space-time code is one of means that makes channel capacity approach theoretical value. Space-time code as well as other relative signal processing technologies has attracted abroad attention. From not only technology, but also market and economy, CDMA will play much important role in the future telecommunication technology as one of 3G core technologies.So how to increase capacity and performance of CDMA system using advanced space-time code technology and MIMO ones recently have been research hotspot.Beginning from space-time channel model, this research subject discusses space-time channel capacity as well as space-time encoding and decoding algorithms. It emphasizes on the application research of two space-time code, details the space-time multi-user detection algorithms combining with space-time code technique. This research's primary studies are following:(1). Analyzing the limit and disadvantage of existing layered space-time multi-user detection algorithms; this study proposes an improved one based on grouping.(2). Inspired from H~∞robust control technique, this research applies H~∞filtering to MUD, and proposes a new MUD algorithm based on robust Kalman filtering. Because it can rapidly converge when the statistical property of interferences or noises are unknown, this algorithm has better performance than existing blind adapting MUD based Kalman filtering.(3). Discuss the method and performance of existing MUD combining with space-time code, and bring forward a lower computing complexity ST-MUD based on idea of decreasing order of matrix and parallel processing. Then the performance of this method is verified by new robust Kalman filtering.(4). Investigate effect of frequency-selective channel on detecting performance of space-time code, and research the traditional layered space-time MUD and STBC MUD under MC-CDMA environment. Discuss the algorithms and performance ST-MUD in the MC-CDMA system.