Adaptive joint detection and estimation in MIMO systems: a hybrid systems approach

• Published in: IEEE transactions on signal processing Vol. 54; no. 5; pp. 1629 - 1644
• Main Authors: Kulatunga, H., Kadirkamanathan, V.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.05.2006; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Adaptive systems; Applied sciences; Code division multiple access; Coding, codes; Complexity; Computational complexity; Density; Detection, estimation, filtering, equalization, prediction; Exact sciences and technology; Fading; Filtering; Hybrid systems; Information, signal and communications theory; Joint estimation and detection; MIMO; Multiaccess communication; multiple models; Multiuser detection; multiuser detection (MUD); Optimization; Receivers; Signal and communications theory; Signal processing algorithms; Signal, noise; State estimation; Systems engineering and theory; Telecommunications and information theory; Transmitters; Parameter estimation; Noise reduction; Wireless telecommunication; Optimal estimation; multiuser detection (MUD); Hybrid system; Probability density; Linear complexity; State estimation; Joint estimation and detection; Bayes estimation; Fading; MIMO system; Multiple access; Adaptive detection; Systems theory; Algorithm; Computational complexity; Information transmission; Joint detection; Interference suppression; Model theory; Code division multiple access; On line processing; multiple models
• ISSN: 1053-587X; 1941-0476
• DOI: 10.1109/TSP.2006.871964

An adaptive receiver based on hybrid system theory is developed for a multiuser multiple-input multiple-output (MIMO) fading code-division multiple-access (CDMA) system. The basic idea is to treat the transmitted symbols and channel gains as unknown states (discrete and continuous) within a hybrid systems framework. The Bayesian-inference-based state estimation is derived using multiple model theory resulting in an optimal joint sequence estimator, which is shown to be intractable in its computational complexity. A suboptimal receiver (IMM-SIC) is then derived based on the well-known Interacting Multiple Model (IMM) algorithm and successive interference cancellation (SIC) scheme. This paper shows the specific approximations made to the probability densities of the optimal receiver in deriving the IMM-SIC receiver with complexity linear in number of users. This receiver design is well suited for online recursive processing of space-time coded CDMA system, where the decoding stage is incorporated within the multiple model framework.