Real time cross-layer adaptation for minimum energy wireless image transport using bit error rate control

In wireless multimedia systems, significant power is consumed in processing image/video content This research looks specifically at the energy cost of wireless image/video transport focusing on image quality as an end metric. The quality of received image/video content depends on the effective bit error rate of the communication channel and the amount by which the image/video data is compressed prior to transmission. For a specified value of received signal quality (as determined by PSNR), the combination of the two that results in minimal RF energy consumption is first determined via an optimization procedure. Then across varying channel conditions, the baseband signal is companded and power is saved by re-biasing the RF power amplifier (PA), while maintaining the "optimal" transmission bit error rate value determined in the first step. Closed loop feedback control is used to guarantee that the received image/video quality remains within the limits set by the user. For a range of PSNR values, the average Energy/image in PA reduces by 50%, where the reference is a static system without channel quality and image quality adaptation.