CIF: Small: Scalable Multimedia with Unequal Error Protection

University Of California-San Diego, La Jolla CA

Investigators

Abstract

Scalable Multimedia with Unequal Error Protection Pamela C. Cosman Laurence B. Milstein Abstract In today?s communications environment, it is important to have rich media content (images, audio, video) that can scale up or down depending on availability of resources. In quality scalable multimedia, some portions of a bit stream contain information that allows a moderate quality reconstruction of the image or video, and additional portions of the bit stream allow the source to be reconstructed at progressively higher quality. We consider the transmission of scalable multimedia data (image and video) through variable types of channels, with a focus on providing different levels of unequal error protection (UEP) appropriate for different levels of information importance and suitable for the channel conditions. There are many techniques for providing protection against errors, including forward error protection (FEC), hierarchical modulation, and leaky and partial prediction in video coding. Our research involves two new techniques for combining hierarchical modulation with either image or video to produce enhanced performance. We consider a MIMO-based technique, in which MIMO space-time coding is used to increase reliability for the most important information in the scalable image or video data, whereas MIMO spatial multiplexing is used to increase data rate for the less important information. This is combined and optimized with existing techniques where unequal error protection is achieved by transmitting different power levels on multiple antennas. The hierarchical approaches for UEP, as well as the MIMO techniques for UEP, are considered in conjunction with FEC and with leaky/partial prediction mechanisms for scalable video. We also consider UEP for cooperative communications, where a virtual MIMO array is formed out of cooperating nodes. Lastly, we investigate the effects of delay considerations in UEP.