BER Analysis of M-QAM with Packet Combining Over Space-Time Block Coded MIMO Fading Channels

• Published in: IEEE transactions on wireless communications Vol. 7; no. 3; pp. 799 - 805
• Main Authors: Aissa, Sonia, Aniba, Ghassane
• Format: Journal Article
• Language: English
• Published: Piscataway, NJ IEEE 01-03-2008; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Analytical models; Applied sciences; Assessments; Automatic repeat request; AWGN; Bit error rate; Block codes; Blocking; Channels; Codes; Constellations; Error analysis; Exact sciences and technology; Fading; Mathematical analysis; MIMO; Performance analysis; Quadrature amplitude modulation; Systems, networks and services of telecommunications; Telecommunications; Telecommunications and information theory; Transmission and modulation (techniques and equipments); Wireless communication; Performance evaluation; ARQ; Space-time block coding (STBC); Block code; Space-time codes; AWGN; Quadrature amplitude modulation; Bit error rate; Mapping; AWGN channels; M ary modulation; packet combining; multiple- input multiple-output (MIMO); Fading channels; MIMO system; Logarithmic function; Rayleigh channels; Error function; Likelihood ratio; BER; Case study; Simulation; Analytical method; Approximation error; logarithmic likelihood ratio (LLR); Rayleigh fading; Automatic repeat request
• ISSN: 1536-1276; 1558-2248
• DOI: 10.1109/TWC.2008.060745

We analyze the bit error rate (BER) performance of M-ary quadrature amplitude modulation (M-QAM) when using space-time block coding (STBC) along with packet combining triggered by automatic repeat request (ARQ) retransmission over multiple-input multiple-output (MIMO) fading channels. Specifically, adopting a log-likelihood ratio (LLR) based approach and considering the 16-QAM case of study, we provide an exact formulation for the aggregate LLR distribution in the case the STBC codeword can be transmitted twice, and derive the resulting BER. For higher number of retransmissions, an approximation of the error function is used to derive the LLR distributions and the system's ensuing BER. Considering different values of combined transmissions and M-QAM with possible constellation rearrangement (CoRe), validation of the proposed BER analytical model through simulations and assessment of the advantages of packet combining are provided for transmissions over additive white Gaussian noise (AWGN) channel and orthogonalized MIMO Rayleigh fading channels with different STBC mappings.