Uplink-downlink imbalance in TDMA personal communication systems

Abstract

An important aspect of any channel assignment algorithm should be balancing the performance of uplink and downlink. Differences in receiver performance, diversity and transmit power used at mobiles and base stations are potential sources of imbalance. In addition, there is a fundamental asymmetry between uplink and downlink interference caused by the locations of mobiles and base stations. We investigate the nature of this asymmetry and prove that the uplink frequently has worse interference. Furthermore, this difference shows little dependence on the degree of mobility and is basically associated with the location of mobiles rather than their speed.