Wavelet video compression for iterative wireless transceivers

Over the last decades, there has been an increasing demand for multimedia services provided over both fixed and wireless channels. Designing robust image or video trans- mission systems for these multimedia services is hence of high importance. For the sake of exploring the feasibility of providing video services for mobile users, this thesis investigates the design of wireless video communication systems using the British Broadcasting Corporation's recent proprietary wavelet-based video codec referred to as the Dirac codec. More specifically, the Dirac video codec is capable of achieving an approximately two-fold bit rate reduction over MPEG-2 when compressing high definition video (e.g. 1920x1080 pixels), while achieving a high reconstructed video quality at a low bit-rate. The Dirac video-encoded bitstream is subjected to a rigorous error sensitivity investigation for the sake of assisting us in contriving various joint source-channel coding (JSCC) and decoding schemes for wireless videophones. Unequal Error Protection (UEP) is an attractive technique of implementing JSCC. Based on the Dirac video codec's bit sensitivity studies, an Unequal Error Protection (UEP) scheme using turbo-equalized Irregular Convolutional Codes (IRCCs) was de- signed. Our UEP scheme allocates a lower channel coding rate to highly sensitive bits and a higher channel coding rate to less sensitive bits, while keeping the coding-rate of the UEP the same as that of the Equal Error Protection (EEP) benchmarker. Furthermore, an Iterative Source-Channel Decoding (ISCD) scheme, which exploits the residual redundancy left in the source encoded bitstream for the sake of improving the attainable system performance was investigated. Hence, a novel ISCD scheme employing a specific bit-to-symbol mapping scheme referred to as Over-Complete Mapping (OCM) was proposed. The proposed scheme benefits both from the residual redundancy inherent in the source encoded bitstream as well as from the intentional redundancy imposed by the specific over-complete source mapping. This allows us to design an attractive video transmission scheme having a high error resilience at a reasonable complexity and a low