Lower bound on the average power consumption of CDMA mobile wireless users communicating via satellite

The new generation of mobile communication systems takes advantage of satellite infrastructure. In this kind of communication system, terrestrial users transmit and receive information to and from the satellite above them. One of the main challenges in mobile wireless communication is to minimize power consumption in order to maximize battery life. The communication procedure that consumes most of the battery´s energy is transmission but it is possible to reduce the transmitter power by increasing the gain of the satellite´s receiver antenna. Since users are randomly located, we treat the problem from a statistical point of view. The statistic that we take into consideration is the geographical density distribution function of the user´s location in the spot coverage area. The average transmitting power is a spatial integral of the transmitted power over the antenna pattern weighted by the geographical density distribution function of the users. We derive the lower bound on the average terrestrial user´s power consumption in relation to the antenna pattern that defines it. The synthesis is performed for a code division multiple access (CDMA) communication system