Determination of Base Station Emission Power Change in a Mobile Network Cell with Movable Users

This paper considers base transceiver station (BTS) emission power change in the cell-organized mobile network with dynamic power control, due to users’ moving. Such power adjustment contributes to energy saving and environment pollution reduction. We analyzed mutual influence of user’s moving speed, users’ surface distribution and propagation coefficient γ on BTS power variations. It is proved that users’ concentration near BTS, greater γ (in urban areas), faster user’s moving and greater connection duration contribute to BTS power increase of several tens of percent in real conditions. We present two examples when mean user’s moving distance is 30% of mobile cell radius: 1) power of one movable user is increased more than 50% when distance between user and BTS is uniformly distributed (decreasing users’ surface density); 2) emission power is decreased 2.5% when users are uniformly distributed (there are more users near a cell rim). BTS power has nearly constant value in the second example, because in our model users, crossing the cell rim, are replaced by users from adjacent cells, who are moving towards BTS. The analysis results are verified by Monte Carlo simulation, where user’s starting position, displacement and angle of moving are determined based on randomly generated numbers

Forward-link performance of CDMA cellular system

The impact of the propagation path-loss exponent on the forward performance of a direct-sequence code-division multiple-access (DS-CDMA) cellular system is investigated. For this purpose, a simple analytical model based on the inverse power-of-distance path-loss exponent law is developed. The problem of finding proper power-control factors is considered. According to path-loss exponent, the proper power-control factors are estimated for optimum performance. With these factors, results show that the capacity is reduced by a half by changing path-loss exponent from 4.5 to 2.5. For this range in path-loss exponent, power control can approximately double the capacity compared to the case of no power contro