Intra-cell allocation information and inter-cell interference distribution based TPC for high-speed CDMA packet radio

We aim to establish a highly efficient transmitting power control (TPC) scheme suitable for the reverse link of high-speed CDMA packet communication systems. Reservation-based access is assumed to be used for packet transmission in the reverse link. First, we describe a hybrid TPC that we created to cope with average interference changes. The target receiving power in the hybrid TPC is set according to the interference averaged over a comparatively long period of time. We show, using experiments on our high-speed packet communication experimental system, that hybrid TPC can effectively reduce transmission power consumption and PER compared with basic receiving power based TPC. Furthermore, we need to change the transmitting power according to the instantaneous interference to cope with instantaneous interference changes slot by slot. However, in a high-speed packet communication system, the interference level can change dramatically in a very short period of time. The TPC of cdma2000 or W-CDMA cannot efficiently cope with rapidly and greatly changing interference levels. Therefore, we created another two novel TPCs. Interference is divided in these TPCs into intra-cell and inter-cell interference. The supposed inter-cell interference level is changed according to the change in the probability distribution of the inter-cell interference, and the necessary transmitting power for a packet is calculated based on intra-cell allocation information and the supposed inter-cell interference level. Computer simulations show that, with the proposed TPCs, throughput can be increased by more than 200% compared with the type of TPC used in cdma2000 or W-CDMA, and the transmitting power consumption in a mobile host (MH) can also be vastly reduced.