Title :
Adaptive radio for multimedia wireless links
Author :
Chien, Charles ; Srivastava, Mani B. ; Jain, Rajeev ; Lettieri, Paul ; Aggarwal, Vipin ; Sternowski, Robert
Author_Institution :
Rockwell Inst. Sci. Center, Thousand Oaks, CA, USA
fDate :
5/1/1999 12:00:00 AM
Abstract :
The quality of wireless links suffers from time-varying channel degradations such as interference, flat-fading, and frequency-selective fading. Current radios are limited in their ability to adapt to these channel variations because they are designed with fixed values for most system parameters such as frame length, error control, and processing gain. The values for these parameters are usually a compromise between the requirements for worst-case channel conditions and the need for low implementation cost. Therefore, in benign channel conditions these commercial radios can consume more battery energy than needed to maintain a desired link quality, while in a severely degraded channel they can consume energy without providing any quality-of-service (QoS). While techniques for adapting radio parameters to channel variations have been studied to improve link performance, in this paper they are applied to minimize battery energy. Specifically, an adaptive radio is being designed that adapts the frame length, error control, processing gain, and equalization to different channel conditions, while minimizing battery energy consumption. Experimental measurements and simulation results are presented to illustrate the adaptive radio´s energy savings
Keywords :
adaptive control; adaptive equalisers; equalisers; fading channels; land mobile radio; multimedia communication; radio links; radiofrequency interference; QoS; adaptive equalization; adaptive radio; battery energy consumption minimisation; channel variations; commercial radios; energy savings; error control; experimental measurements; flat-fading; frame length; frequency-selective fading; interference; link performance; link quality; low implementation cost; multimedia wireless links; processing gain; quality-of-service; radio parameters; simulation results; system parameters; time-varying channel degradations; Batteries; Costs; Degradation; Error correction; Fading; Frequency; Interference; Programmable control; Quality of service; Time-varying channels;
Journal_Title :
Selected Areas in Communications, IEEE Journal on