Adaptive radio for multimedia wireless links

摘要

The quality of wireless links suffers from time-varying channelndegradations such as interference, flat-fading, and frequency-selectivenfading. Current radios are limited in their ability to adapt to thesenchannel variations because they are designed with fixed values for mostnsystem parameters such as frame length, error control, and processingngain. The values for these parameters are usually a compromise betweennthe requirements for worst-case channel conditions and the need for lownimplementation cost. Therefore, in benign channel conditions thesencommercial radios can consume more battery energy than needed tonmaintain a desired link quality, while in a severely degraded channelnthey can consume energy without providing any quality-of-service (QoS).nWhile techniques for adapting radio parameters to channel variationsnhave been studied to improve link performance, in this paper they arenapplied to minimize battery energy. Specifically, an adaptive radio isnbeing designed that adapts the frame length, error control, processingngain, and equalization to different channel conditions, while minimizingnbattery energy consumption. Experimental measurements and simulationnresults are presented to illustrate the adaptive radio's energy savings