Improving the Energy Efficiency of CDMA Power Control over Frequency-Selective Channels

In this letter, we derive an energy-efficient power control for the uplink of a code division multiple access (CDMA) wireless network over a frequency-selective and slow-fading channel, in which terminals already code-locked to the base station coexist with some terminals still in the code alignment stage. This formulation is obtained through the application of a generalized noncooperative game with strict incomplete information. This framework allows us: i) to capture the tradeoff between saving as much energy as possible and obtaining good performance, whose metrics depends on each terminal´s operational status; and ii) to derive a low-complexity distributed algorithm, based on iterative best-response dynamics, which increases the performance of the network in terms of received information bits per energy consumed at the transmit side. This improvement, that highly depends on the system parameters and the network traffic characteristics, can range up to 40%.