Power-minimized bit allocation for video communication over wireless channels

Abstract

Video communication over wireless links using handheld devices is a challenging task due to the time-varying characteristics of the wireless channels and limited battery resources. Rate-distortion (RD) analysis plays a key role in video coding and communication systems, and usually the RD relation does not assume any power constraint. We investigate the relations of rate, distortion and power consumption. Based on those relations, we propose a power-minimized bit-allocation scheme considering the processing power, for source coding and channel coding, jointly with the transmission power. The total bits are allocated between source and channel coders, according to wireless channel conditions and video quality requirements, to minimize the total power consumption for a single user and a group of users in a cell, respectively. Simulation results show that our proposed joint power-control and bit-allocation scheme achieves high power savings compared to the conventional scheme.