Practical Interference Exploitation Precoding Without Symbol-by-Symbol Optimization: A Block-Level Approach

Ang Li

doi:10.1109/TWC.2022.3222780

Practical Interference Exploitation Precoding Without Symbol-by-Symbol Optimization: A Block-Level Approach

2023-06-01

9

OA

AI

DOI：10.1109/TWC.2022.3222780

Original

Original request for help

Save

Abstract

En 中文

In this paper, we propose a constructive interference (CI)-based block-level precoding (CI-BLP) approach for the downlink of a multi-user multiple-input single-output (MU-MISO) communication system. Contrary to existing CI precoding approaches which have to be designed on a symbol-by-symbol level, here a constant precoding matrix is applied to a collection of symbols within a given transmission block, thus significantly reducing the computational costs over traditional CI-based symbol-level precoding (CI-SLP) as the CI-BLP optimization problem only needs to be solved once per block. For both PSK and QAM modulation, we formulate an optimization problem to maximize the minimum CI effect over the block subject to a block- rather than symbol-level power budget. We mathematically derive the optimal precoding matrix for CI-BLP as a function of the Lagrange multipliers in closed form. By formulating the dual problem, the original CI-BLP optimization problem is further shown to be equivalent to a quadratic programming (QP) optimization. Numerical results validate our derivations, and show that the proposed CI-BLP scheme achieves improved performance over the traditional CI-SLP method, thanks to the relaxed power constraint over the considered block of symbol slots.

Keywords:

Precoding

Symbols

Optimization

Interference

Quadrature amplitude modulation

Modulation

Phase shift keying

MU-MISO

symbol-level precoding

constructive interference

optimization

Lagrangian

Practical Interference Exploitation Precoding Without Symbol-by-Symbol Optimization: A Block-Level Approach

Abstract

Journal

Organization