Performance Comparison of Energy-Efficient Power Control for CDMA Code Acquisition and Detection

This paper investigates the performance of distributed power control techniques in the uplink of a flat-fading CDMA wireless network, based on noncooperative game theory. Two energy-efficient criteria, tailored for data detection and code synchronization, are compared in terms of achieved utility at the Nash equilibrium, showing that the optimal power allocation devised for data detection is not the best solution during synchronization, and analogously the optimal allocation for code acquisition does not provide the best performance during data detection. Closed-form expressions for the optimal powers at the Nash equilibrium are derived, and a unified formulation is proposed to allow a more elaborated power allocation method to be adopted, in which the terminals, using the synchronization-oriented approach, can revert to the data-detection optimal criterion after synchronization is over.