Integrated rate, power and cell control in cellular CDMA systems: an interference-balancing approach

In this paper, a novel combined rate, power and cell control scheme that minimizes transmit bit energy while gracefully implementing the congestion control is proposed and studied. The reverse link in a code division multiple access (CDMA) system with a high degree of traffic fluctuation temporally as well as spatially is considered. The proposed radio resource management scheme attempts to reduce the interference power variation among base station antennas that can exist in a real radio network. Transmission rates of those users in the congested (non-congested) cells are decreased (increased); hence, the proposed scheme is appropriate for delay-insensitive variable-bit-rate applications. Minimization of average transmit bit energy is achieved, subject to maintenance of individual target Eb/I0 for each user. Two algorithms, one directly minimizing the transmit bit energy, and the other doing so indirectly using the measured pilot power, are presented. It can be shown that both algorithms select the optimal base station if forward- and reverse-link gains are reciprocal; however, the latter gain is decentralized and uses only the local measurements and is amenable for practical implementation.