An Adaptive Zero Forcing Maximum Likelihood Soft Input Soft Output MIMO Detector

Igor JELOVAN  Gorazd KANDUS  Toma JAVORNIK 

Publication
IEICE TRANSACTIONS on Communications  Vol.E92-B  No.2  pp.507-516
Publication Date: 2009/02/01
Online ISSN: 1745-1345
Print ISSN: 0916-8516
Type of Manuscript: PAPER
Category: Wireless Communication Technologies
Keyword: 
MIMO,  iterative detection,  AZFML algorithm,  soft input soft output,  IEEE 802.16, 

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Summary: 
An adaptive zero forcing maximum likelihood soft input soft output (AZFML-SISO) detector for multiple input multiple output (MIMO) wireless systems is presented. Its performance in an iterative MIMO receiver is analyzed. The AZFML-SISO detector calculates the soft outputs, applying the ML approach to the list that contains only those signal vectors limited by a hypersphere around the zero forcing (ZF) solution. The performance of the algorithm is evaluated on a communication system based on the standard for single carrier broadband wireless communication IEEE 802.16, with three transmit and three receive antennas. It is shown by computer simulation that the computational complexity in an average sense of the receiver running the AZFML-SISO algorithm is reduced by 90% at the SNR values of 30 dB and by 50% for SNR values of 15 dB in comparison to the receiver with an ML detector, while the system performance degrades by less than 1 dB.