Optimal Allocation of Power Pool for Two-Cell Single-User Joint Transmission

TL;DR

This paper proposes a power pooling strategy for two-cell single-user joint transmission to optimize sum-rate or power efficiency, providing a convex optimization solution with verified performance improvements.

Contribution

It introduces a novel power pooling framework and derives a closed-form water-filling solution for sum-rate maximization in joint transmission.

Findings

Power pooling increases system sum-rate.

The optimization problem is convex with a unique solution.

Simulation confirms performance gains over traditional methods.

Abstract

Joint transmission is a kind of cooperative transmission technology, which converts other cell interference into signal. In this letter, for single-user joint transmission, we propose that a power pool can be created in order to increase the system sum-rate or lower the power consumption. Then, we investigate the sum-rate maximization problem under this framework. Since it is impossible that subchannel gains for the two base stations are identical, we can obtain a much more concise structure and reduce variables to the half of original problem. And that the closed-form water-filling solution is unique and global optimum, because it is a convex optimization problem. Compared to the power allocation without pooling, the performance gain is verified by simulation.