Power Allocation Games in Wireless Networks of Multi-antenna Terminals

TL;DR

This paper analyzes power allocation games in multi-antenna wireless networks, examining how selfish user strategies impact system performance under different decoding schemes, with a focus on equilibrium properties and efficiency.

Contribution

It introduces and thoroughly analyzes two resource allocation games with multi-antenna terminals, providing new insights into Nash equilibria and sum-rate efficiency under various decoding methods.

Findings

Nash equilibrium exists and is unique in both game settings.

Sum-rate efficiency remains high at equilibrium in typical scenarios.

Coordination mechanisms cause minimal performance loss.

Abstract

We consider wireless networks that can be modeled by multiple access channels in which all the terminals are equipped with multiple antennas. The propagation model used to account for the effects of transmit and receive antenna correlations is the unitary-invariant-unitary model, which is one of the most general models available in the literature. In this context, we introduce and analyze two resource allocation games. In both games, the mobile stations selfishly choose their power allocation policies in order to maximize their individual uplink transmission rates; in particular they can ignore some specified centralized policies. In the first game considered, the base station implements successive interference cancellation (SIC) and each mobile station chooses his best space-time power allocation scheme; here, a coordination mechanism is used to indicate to the users the order in which the receiver applies SIC. In the second framework, the base station is assumed to implement single-user decoding. For these two games a thorough analysis of the Nash equilibrium is provided: the existence and uniqueness issues are addressed; the corresponding power allocation policies are determined by exploiting random matrix theory; the sum-rate efficiency of the equilibrium is studied analytically in the low and high signal-to-noise ratio regimes and by simulations in more typical scenarios. Simulations show that, in particular, the sum-rate efficiency is high for the type of systems investigated and the performance loss due to the use of the proposed suboptimum coordination mechanism is very small.