Power Control and Transmission Rate Management in Cellular Radio Systems.

摘要

The scarce radio spectrum imposes hard limitations on design of cellular radio systems. To provide communication services with high capacity and good quality of service requires powerful methods for sharing the radio spectrum in most efficient way. In practice, all sharing methods introduce interference which is proportional to the transmitter powers. The transmitter power control is a key technique to balance the received signal strength and the interference power, which in turn enables more efficient sharing. Emerging multimedia service can be characterized by different quality of service requirements such as minimum transmission rates. For a real-time service, users must be guaranteed a tolerable minimum rate. However, non-real time applications, i.e. delay insensitive applications, may temporarily lower their transmission rates even to zero, utilizing any excess capacity that the system has. In this thesis, the transmitter power control and the transmission rate management problems are examined. For the fixed-rate systems, we show that considerable improvements in the convergence speed and energy efficiency can be achieved. For the multi-rate (multimedia) system, we examine certain class of combined transmitter power control and transmission rate management algorithms. In addition, implementations of these algorithms are briefly discussed.