# Robust Cooperative Relay Beamforming

## TL;DR

This paper introduces a robust distributed relay beamforming method that addresses channel uncertainty by reformulating a complex non-convex problem into a solvable semi-definite program, improving performance in relay networks.

## Contribution

It presents a novel robust beamforming design using the worst-case approach, transforming a semi-infinite problem into a semi-definite program for better reliability.

## Key findings

- Performance improvement over existing methods
- Reduced transmit power
- Lower symbol error probability

## Abstract

In this paper, the robust distributed relay beamforming problem is solved using the worst case approach, where the problem solution has been involved because of the effect of uncertainty of channel knowledge on the quality of service (QoS) constraints. It is shown that the original robust design, which is a non-convex semi-infinite problem (SIP), can be relaxed and reformed to a semi-definite problem (SDP). Monte-Carlo simulations are presented to verify the performance improvement of our proposed robust problem over existing robust and non-robust problems in terms of transmit power and symbol error probability.