Adaptive and Iterative Multi-Branch MMSE Decision Feedback Detection Algorithms for Multi-Antenna Systems

Abstract

In this work, decision feedback (DF) detection algorithms based on multiple processing branches for multiinput multi-output (MIMO) spatial multiplexing systems are proposed. The proposed detector employs multiple cancellation branches with receive filters that are obtained from a common matrix inverse and achieves a performance close to the maximum likelihood detector (MLD). Constrained minimum mean-squared error (MMSE) receive filters designed with constraints on the shape and magnitude of the feedback filters for the multi-branch MMSE DF (MB-MMSE-DF) receivers are presented. An adaptive implementation of the proposed MB-MMSE-DF detector is developed along with a recursive least squares-type algorithm for estimating the parameters of the receive filters when the channel is time-varying. A soft-output version of the MB-MMSE-DF detector is also proposed as a component of an iterative detection and decoding receiver structure. A computational complexity analysis shows that the MB-MMSE-DF detector does not require a significant additional complexity over the conventional MMSE-DF detector, whereas a diversity analysis discusses the diversity order achieved by the MB-MMSE-DF detector. Simulation resultsshow that the MB-MMSE-DF detector achieves a performance superior to existing suboptimal detectors and close to the MLD, while requiring significantly lower complexity.Index Terms-MIMO systems, spatial multiplexing, decision feedback receivers, iterative methods.

Cloud-Driven Multi-Way Multiple-Antenna Relay Systems: Best-User-Link Selection and Joint Mmse Detection

“…The ML receiver calculates an estimate of the vector of symbols sent by the sourcesx[i]. Other suboptimal detection techniques could be considered in future work [17], [18], [19], [20], [21], [22], [54], [24], [25], [26], [27], [28], [31], [32], [33].…”

Cloud-Aided Max-Link Relay Selection for Two-Way Cooperative Multi-Antenna Systems

“…Other suboptimal detection techniques could be considered in future work [34], [35], [36], [37], [38], [39], [68], [41], [42], [43], [44], [45], [46], [47], [48]. Otherwise, if the relay selection algorithm decides to operate in the Max-Link-SR mode, the received signal from S to R k is organized in an U M S × 1 vector y S,R k [i] given by…”

Multibeam joint detection

“…In this sense, the multibranch successive interference cancellation (MB-SIC) algorithm generalizes the standard SIC algorithm using multiple SIC algorithms in parallel branches [30]. The MB-SIC algorithm relies on different ordering patterns and produces multiple candidates for detection to get a performance closer to that of the ML detector.…”

“…30) with M = H H H + σ 2 I for the MMSE detector and M = H H H for the ZF detector. As an example, M −1 can be expressed as a Taylor series, I − M) n ,(1.31) as long as the spectral radius of M is less than 2.…”