Authors:
Andreas Ahrens
1
and
César Benavente-Peces
2
Affiliations:
1
University of Technology, Business and Design, Germany
;
2
Universidad Politécnica de Madrid, Spain
Keyword(s):
Multiple-input multiple-output system, Singular-value decomposition, Bit allocation, Power allocation, Wireless transmission, Multiuser transmission.
Related
Ontology
Subjects/Areas/Topics:
Channel Coding, Modulation and Multi-User Detection
;
Detection, Decoding and Diversity Techniques
;
MIMO Systems and Techniques
;
Telecommunications
;
Wireless Information Networks and Systems
Abstract:
In this contribution we jointly optimize the number of multiple-input multiple-output (MIMO) layers and the number of bits per symbol within an iteratively-detected multiuser MIMO downlink (DL) transmission scheme under the constraint of a given fixed data throughput and integrity. Instead of treating all the users jointly as in zero-forcing (ZF) multiuser transmission techniques, the investigated singular value decomposition (SVD) assisted DL multiuser MIMO system takes the individual user’s channel characteristics into account. In analogy to bit-interleaved coded irregular modulation, we introduce a MIMO-BICM scheme, where different user-specific signal constellations and mapping arrangement were used within a single codeword. Extrinsic information transfer (EXIT) charts are used for analyzing and optimizing the convergence behaviour of the iterative demapping and decoding. Our results show that in order to achieve the best bit-error rate, not necessarily all user-specific MIMO lay
ers have to be activated.
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