A Diversity-Embedding Approach for High-Rate Reliable Multimedia Wireless Communications

University Of Texas At Dallas, Richardson TX

Investigators

Abstract

There is a fundamental tradeoff between rate and reliability (diversity) in multiple-antenna wireless communications. This research views diversity as a systems resource and explores allocation of this resource to achieve a desirable rate-diversity tradeoff in multimedia wireless communications. Multimedia data is often complex and consists of various components with different rate/reliability requirements. For example, a real-time data stream is a candidate to receive more diversity (protection) than non-real-time data. Other examples include complex data streams such as compressed video, whose various components require different levels of error protection. Over-provisioning of diversity to one data component will mean the loss of rate to that and other data components, a waste of system resources. The focus of this research is on the creation of a flexible pool of space-time resources rather than the design of fixed maximum-diversity schemes. The investigators design high-rate space-time codes that have a high-diversity code embedded within them. This allows a form of wireless communications where the high-rate code opportunistically takes advantage of good channel realizations while the embedded high-diversity code ensures that at least part of the information is decoded reliably. The proposed diversity-embedding codes do not require channel knowledge at the transmitter and outperform time-sharing schemes. Using the proposed coding scheme, each traffic type constitutes a transmission layer that operates at a suitable rate-diversity tradeoff point. The investigators explore this point of view with designissues, specific code constructions, and application to multimedia communications.