Energy-Efficient Power Control in Multipath CDMA Channels via Large System Analysis

摘要

This paper is focused on the design and analysis of power control proceduresfor the uplink of multipath code-division-multiple-access (CDMA) channels basedon the large system analysis (LSA). Using the tools of LSA, a new decentralizedpower control algorithm aimed at energy efficiency maximization and requiringvery little prior information on the interference background is proposed;moreover, it is also shown that LSA can be used to predict with good accuracythe performance and operational conditions of a large network operating at theequilibrium over a multipath channel, i.e. the power,signal-to-interference-plus-noise ratio (SINR) and utility profiles acrossusers, wherein the utility is defined as the number of bits reliably deliveredto the receiver for each energy-unit used for transmission. Additionally, anLSA-based performance comparison among linear receivers is carried out in termsof achieved energy efficiency at the equilibrium. Finally, the problem of thechoice of the utility-maximizing training length is also considered. Numericalresults show a very satisfactory agreement of the theoretical analysis withsimulation results obtained with reference to systems with finite (and not solarge) numbers of users.