Delay–Rate–Distortion Optimized Rate Control for End-to-End Video Communication Over Wireless Channels
In addition to the rate-distortion (R-D) behavior, in a real-time wireless video communication system, the end-to-end delay would also significantly affect the overall video reception quality. To analyze, control, and optimize the R-D behavior under the end-to-end delay constraint, in this paper we extend the traditional R-D optimization (RDO) for the wireless video communication system and formulate a novel delay-RDO-based rate control problem, by investigating the allocation of end-to-end delay to different delay components. It aims at minimizing the average total end-to-end distortion under the transmission rate and end-to-end delay constraints, by a joint selection of both the source coding and the channel coding parameters. The wireless channel is represented by a finite-state Markov channel model characterizing the time-varying process and predicting the future channel condition. As applicable solutions, a practical algorithm based on the Lagrange multiplier approaches, Karush-Kuhn-Tucker conditions, and sequential quadratic programming methods is developed. The experimental results demonstrate the superiority of the proposed algorithm over the existing schemes.