Uplink power control for TDMA portable radio channels

Abstract

A closed-loop power control algorithm for the portable transmitter is introduced for TDMA (time division multiple access) portable radio systems. This method enables the portable radio handset to output no more power than is required at its access port receiver for the desired performance. This avoids causing excessive interference to cochannel ports. The fading of a radio channel due to shadowing effects and moderate-rate multipath propagation can be tracked and mitigated simultaneously. By simulating a prototype hardware implementation of the receiver baseband processing, the authors study the link performance as a function of signal to impairment ratio under different channel conditions. It is found that radio link performance can be significantly improved with little additional complexity and little signaling overhead. An improvement of as much as 9 dB was found for slow fading channels impaired by noise, and as much as 7 dB was found for slow fading channels impaired by synchronous interference. >