# Modified zero forcing decoder for ill-conditioned channels

## TL;DR

This paper introduces a modified zero-forcing decoder for ill-conditioned MIMO channels that improves performance by focusing on well-conditioned channel matrix elements, using a reformulated QR decomposition and a hybrid approach.

## Contribution

It proposes a novel MZF decoder that enhances zero-forcing performance on ill-conditioned channels by selectively ignoring problematic matrix elements.

## Key findings

- Significant performance improvement over traditional ZF decoder.
- Hybrid decoder combining ZF and MZF adapts to channel conditions.
- Minimal increase in computational complexity.

## Abstract

A modified zero-forcing (MZF) decoder for ill-conditioned Multi-Input Multi-Output (MIMO) channels is proposed. The proposed decoder provides significant performance improvement compared to the traditional zero-forcing decoder by only considering the well-conditioned elements of the channel matrix. This is achieved by reformulating the QR decomposition of the channel matrix by neglecting the elements which are responsible for the correlation. By combining the traditional ZF with the MZF decoders, a hybrid decoder can be formed that alternates between the traditional ZF and the proposed MZF according to the channel condition. We will illustrate through simulations the significant improvement in performance with little change in complexity over the traditional implementation of the zero forcing decoder.