Efficient power management based on target BER control and optimum mode selection for wireless video in CDMA systems

Abstract

Third generation communication system must accommodate wireless video service. The capacity of a code division multiple access (CDMA) system is limited by the total interference power received at each base station. Therefore, it is desirable to minimize the power consumption and at the same time to maximize the quality of service (QoS) level of wireless video service. Because the importance of the information contained in each video packet differs, it may be advantageous to adjust the target bit error rate (BER) of the video packet. In addition, optimum mode selecition is one of the most important optimization tasks in the research of video codec. In this dissertation, therefore, we focus on efficient power management schemes based on target BER control and mode selection for wireless video service in CDMA systems. For video quality rating, a suitable metric is introduced: the average peak signal to noise ratio (PSNR) or the average channel-induced PSNR degradation. First, we propose efficient power management schemes based on target BER control for an image sequence in CDMA systems. To evaluate the importance of each video packet, we consider the distortion induced by the loss of the video packet. We optimize the target BERs for video packets in such a way that the average transmitted power be minimized under the constraint of maximum distortion. Based on the derived target BERs, we propose an optimum power management scheme for video transmission. A modified scheme is also presented to avoid additional signaling and to reduce hardware complexity. Second, an optimum target BER control scheme is proposed for INTRA refreshed single image sequence in CDMA systems. The end-to-end distortion of H.263 video data is first modeled when the error concealment schemes are employed. This distortion model takes into account the error propagation effects caused by the motion compensation. Then, based on the model, the target BERs of the image frames are optimized in such ...