Power allocation for social benefit through price-taking behaviour on a CDMA reverse link shared by energy-constrained and energy-sufficient data terminals

Abstract

We allocate power to maximise “social benefit” in the uplink of a CDMA cell populated by data terminals, each with its own data rate, channel gain, willingness to pay (wtp), and link-layer configuration, and with energy supplies that are limited for some, and inexhaustible for others. For both types, appropriate performance indices are specified. The social optimum can be achieved distributively through price-taking behaviour, if prices are based on a terminal's fraction of the total power received. For a given price, a terminal can choose its optimal power fraction without knowing the choices made by others because this fraction directly determines its signal-to-interference ratio (SIR), and hence its performance. By contrast, other schemes produce “games” in which terminals' optimal choices depend on each other. A “decoupled” solution has important technological and “marketing” advantages. The socially-optimal price is common to all terminals of a given energy class, and an energy-constrained terminal pays in proportion to the square of its power fraction.