Resource allocation and performance issues in the design of wireless communication networks.

摘要

Evolving cellular and wireless personal communication networks require power control at the physical layer for interference management and energy savings. This research is directed toward autonomous power management and multiple access control for energy savings with uncompromised quality of service. A central issue addressed is how a mobile node in a wireless network should vary its transmitter power so that energy consumption is minimized. Explicit solutions are obtained for channels with stationary, extraneous interference, and a dynamic power management algorithm based on these solutions is developed. Numerical methods are used to obtain various performance measures and suggest low-power optimal transmission policies. Simulation is used to validate the design and study more complicated network scenarios, including the case where multiple, mutually interfering transmitters operate in a highly responsive interference environment. Power management is compared with conventional power control for models based on frequency/time division (F/TDMA) and code division (CDMA) multiple access cellular networks. The question of whether a TDMA-like state can be induced on asynchronous channels in such a way as to lower interference and energy consumption is addressed. Through analysis and simulation we find conditions under which it is desirable to induce time division, and suggest how autonomous power management may be used for this purpose. This problem also takes the form of a multi-player, cooperative game, in which case we study the set of outcomes which form the "core." Then it is of interest to determine the cost (or payoff) incurred by individual nodes (players), as well as to investigate their incentive to cooperate. With this motivation we characterize the core of symmetric games and show how bounds on the payoff to individuals can be obtained. Results indicate that use of power management yields improved network capacity and stability in addition to substantially improved battery life at the mobile terminals.