  This PhD thesis considers the performance evaluation and enhancement of video
communication over wireless channels. The system model considers hybrid
automatic repeat request (HARQ) with Chase combining and turbo product codes
(TPC). The thesis proposes algorithms and techniques to optimize the
throughput, transmission power and complexity of HARQ-based wireless video
communication. A semi-analytical solution is developed to model the performance
of delay-constrained HARQ systems. The semi-analytical and Monte Carlo
simulation results reveal that significant complexity reduction can be achieved
by noting that the coding gain advantage of the soft over hard decoding is
reduced when Chase combining is used, and it actually vanishes completely for
particular codes. Moreover, the thesis proposes a novel power optimization
algorithm that achieves a significant power saving of up to 80%. Joint
throughput maximization and complexity reduction is considered as well. A CRC
(cyclic redundancy check)-free HARQ is proposed to improve the system
throughput when short packets are transmitted. In addition, the computational
complexity/delay is reduced when the packets transmitted are long. Finally, a
content-aware and occupancy-based HARQ scheme is proposed to ensure minimum
video quality distortion with continuous playback.
