On the Achievable Throughput Region of Multiple-Access Fading Channels with QoS Constraints

TL;DR

This paper analyzes the effective capacity region of multiaccess fading channels under QoS constraints, showing how adaptive decoding order and power control can enhance throughput in multiuser wireless systems.

Contribution

It introduces optimal decoding and power allocation strategies for multiuser fading channels with QoS constraints, improving throughput performance analysis.

Findings

Varying decoding order increases achievable throughput.

TDMA can outperform superposition coding under certain QoS constraints.

Optimal power allocation enhances effective capacity region.

Abstract

Effective capacity, which provides the maximum constant arrival rate that a given service process can support while satisfying statistical delay constraints, is analyzed in a multiuser scenario. In particular, we study the achievable effective capacity region of the users in multiaccess fading channels (MAC) in the presence of quality of service (QoS) constraints. We assume that channel side information (CSI) is available at both the transmitters and the receiver, and superposition coding technique with successive decoding is used. When the power is fixed at the transmitters, we show that varying the decoding order with respect to the channel state can significantly increase the achievable throughput region. For a two-user case, we obtain the optimal decoding strategy when the users have the same QoS constraints. Meanwhile, it is shown that time-division multiple-access (TDMA) can achieve better performance than superposition coding with fixed successive decoding order at the receiver side for certain QoS constraints. For power and rate adaptation, we determine the optimal power allocation policy with fixed decoding order at the receiver side. Numerical results are provided to demonstrate our results.