Transmitter Power Control for Co-channel Interference Management in Cellular Radio Systems

Transmitter power control is a necessity to combat "near-far" problems in radio systems using receivers with limited "dynamic range" (such as conventional DSCDMA systems). Transmitter power control, however, can also be used to control cochannel interference, i.e. interference from other users using the same channel (code or time slot). For this purpose, it has been shown that the optimum transmitter power configuration is found by solving an eigenvalue problem. The paper reviews some recent results in this area. The basic models as well as the concepts of achievable C/I, up/down-link equivalence and C/Ibalancing are introduced. Both the interference limited (noise-less) case as well as models including thermal noise are treated. Results show that substantial improvements in system capacity can be achieved, particulary in conjunction with Dynamic Channel Allocation. The optimum power control schemes are shown to be robust against implementational shortcomings.