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In this paper, we propose an optimal strategy for the transmission of scalable video over packet-based multiple-input multiple-output (MIMO) systems. The scalable extension of H.264/AVC that provides a combined temporal, quality and spatial scalability is used. For given channel conditions, we develop a method for the estimation of the distortion of the received video and propose different error concealment schemes. We show the accuracy of our distortion estimation algorithm in comparison with simulated wireless video transmission with packet errors. In the proposed MIMO system, we employ orthogonal space-time block codes (O-STBC) that guarantee independent transmission of different symbols within the block code. In the proposed constrained bandwidth allocation framework, we use the estimated end-to-end decoder distortion to optimally select the application layer parameters, i.e., quantization parameter (QP) and group of pictures (GOP) size, and physical layer parameters, i.e., rate-compatible turbo (RCPT) code rate and symbol constellation. Results show the substantial performance gain by using different symbol constellations across the scalable layers as compared to a fixed constellation.

Abstract-An 8 × 8 two-symbol decodable quasi-orthogonal space-time block code (QO-STBC) is presented which can be transmitted across either 8 or 4 antennas with full rate and the same full diversity order. For the 8-transmit-antenna system, a new expression is developed to identify rotation angles that maximize the diversity (eigenvalue) product. In addition, it is shown that the previously proposed sum-eigenvalue maximization criterion for the design of rotation angles is not relevant/applicable and an alternative minimum eigenvalue maximization criterion is suggested. Finally, new optimal rotation angles are obtained by working directly with a pairwise-error-probability (PEP) upperbound expression. For 4-transmit-antenna systems and correlated channel fading conditions, the PEP-upper-bound is modified accordingly to take into account the channel correlation. Using the new PEP-upper-bound we obtain rotation angles that maximize the diversity product and find, contrary to previous results, that the optimized angles are independent of the correlation coefficient. Simulation studies initiated herein demonstrate the advantage of using the proposed codeword across 4 transmit antennas when compared with other 4×4 QO-STBC transmission schemes. For 8 transmit antennas, the studies compare the three selected rotation angle optimization criteria (diversity product, minimum eigenvalue, PEP-upper-bound).Index Terms-Constellation rotation, diversity product, MIMO systems, pairwise-error-probability (PEP), quasi-orthogonal space-time block codes (QO-STBC), sum or minimum eigenvalue maximization.