Selecting the feedback rate for SIR-based power control in wireless TDMA networks with slowly moving terminals

Combating multipath fading degradations only by means of packet retransmissions or data interleaving and coding may lead to intolerable delays for low fading rates. Fast power control, which attempts to track variations in link quality due to multipath fading of own and interfering links, is contrasted with slow power control, where multipath degradations are mitigated by raising the target SIR value. A novel method is developed to limit the short-term power requirements that can occur when employing a fast power control. Numerical results are presented for dual antenna selection diversity receivers. In a Rayleigh fading environment, a slow power control scheme is more desirable when the required link reliability is below 90%, or when terminal velocity is medium or high. A fast scheme is preferable when high link reliability is required.