Layered cooperation for wireless multimedia communications

Cooperative techniques form a new wireless communication paradigm in which terminals help each other in relaying information to combat the random fading and to provide diversity in radio channels. Past work has focused on improving channel reliability through cooperative channel coding. We propose to jointly allocate bits among source coding, channel coding and cooperation to minimize the expected source distortion. Recognizing that not all source bits are equal, we further propose to protect the more important bits through user cooperation. We have simulated four modes of communications that differ in their error protection strategy (equal vs. layered, with vs. without cooperation) with a practical channel coder, and showed that, for i.i.d. Gaussian sources, layered cooperation can achieve significant performance gains over non-layered/non- cooperative communication.