# Joint Precoding and Power Control in Small-Cell Networks With Proportional-Rate MISO-BC Backhaul

## TL;DR

This paper proposes a joint precoding and power control scheme for small-cell networks with MISO-BC backhauls, optimizing power efficiency while handling non-convex constraints and providing closed-form solutions.

## Contribution

It introduces a novel approach to decouple and optimize precoding and power control in MISO-BC backhauls with proportional rates, including closed-form solutions.

## Key findings

- Performance improvement over benchmark schemes
- Closed-form expressions for optimal precoding vectors
- Effective handling of non-convex optimization problem

## Abstract

In the small-cell networks with multiple-input-single-output broadcasting (MISO-BC) backhauls, the joint dirty-paper coding and power control are investigated for the \mbox{MISO-BC} backhauls and access links in order to minimize the system transmit power. Considering the proportional rates of MISO-BC backhauls and flow-conservation constraints, the formulated optimization problem is \mbox{non-convex}. Moreover, the formulated problem couples the precoding vectors with the power-control variables. In order to handle the \mbox{non-convex} optimization problem and decouple the backhaul and access links, the structure of the formulated problem is investigated such that the optimal precoding vectors and optimal power-control variables are independently obtained. Moreover, the optimal precoding vectors are obtained in closed-form expressions. Simulation results are used to show the performance improvement over the benchmark scheme.