Title: Reduced cluster search ML decoding for QO-STBC M-QAM MIMO systems

Authors: Taufik Abrao, Isaque Suzuki, Bruno A. Angelico, Fernando Ciriaco, Paul Jean E. Jeszensky, Fernando Casadevall Palacio

Addresses: Electrical Engineering Department, State University of Londrina (DEEL-UEL), Rod. Celso Garcia Cid – PR445, s/n, Campus Universitario, P.O. Box 6001, Londrina, PR 86051-970, Brazil. ' Electrical Engineering Department, State University of Londrina (DEEL-UEL), Rod. Celso Garcia Cid – PR445, s/n, Campus Universitario, P.O. Box 6001, Londrina, PR 86051-970, Brazil. ' Department of Electrical Engineering, Federal Technological University of Parana (UTFPR), Av. Alberto Carazzai, 1640, Cornelio Procopio, PR 86300-000, Brazil. ' Laboratorio de Comunicacoes e Sinais, Department of Telecommunications and Control Engineering, Escola Politecnica of University of Sao Paulo (LCS-PTC-EPUSP), Av. Prof. Luciano Gualberto, tr. 3, 158, Cidade Universitaria, Sao Paulo, SP, Sao Paulo 05508-900, Brazil. ' Laboratorio de Comunicacoes e Sinais, Department of Telecommunications and Control Engineering, Escola Politecnica of University of Sao Paulo (LCS-PTC-EPUSP), Av. Prof. Luciano Gualberto, tr. 3, 158, Cidade Universitaria, Sao Paulo, SP, Sao Paulo 05508-900, Brazil. ' Department of Signal Theory and Communication (TSC), Universitat Politecnica de Catalunya (UPC), Campus Nord , C/Jordi Girona, 1-3, Barcelona 08034, Spain

Abstract: Since the maximum likelihood (ML) decoding for quasi-orthogonal space-time block codes (QO-STBC) with inner and outer codes multiple-input-multiple-output (MIMO) antenna systems results too complex when the modulation order index and the number of receive antennas increases, an efficient reduced complexity ML-based decoding scheme is proposed in this contribution, aiming to reach promising QO-STBC coded MIMO system throughput × complexity trade-off. Under high-order modulation indexes (16 ≤ M)-QAM, 4 × n_R antennas, with n_R ≥ 1, this work proposes a reduced cluster search ML decoder (RCS-ML) and compares the performance-complexity with the ML decoding approach. Numerical results have indicated no degradation in performance and an increasing reduction in the complexity of RCS-ML decoder when the modulation order increases, been 12.5% of ML decoding complexity for 16-QAM, and <1% for 256-QAM.

Keywords: MIMO antenna systems; quasi-orthogonal space-time block codes; QO-STBC; reduced complexity ML decoding; cluster search; space-time coding; STC.

DOI: 10.1504/IJSCPM.2011.039738

International Journal of Satellite Communications Policy and Management, 2011 Vol.1 No.1, pp.15 - 30

Published online: 11 Mar 2015 *