University of Oulu

Optimization techniques for cell-free massive MIMO system

Saved in:
Author: Wickrama Arachchi, Chamalee1
Organizations: 1University of Oulu, Faculty of Information Technology and Electrical Engineering, Communications Engineering
Format: ebook
Version: published version
Access: open
Online Access: PDF Full Text (PDF, 0.8 MB)
Pages: 29
Persistent link:
Language: English
Published: Oulu : C. Wickrama Arachchi, 2019
Publish Date: 2019-09-10
Thesis type: Master's thesis (tech)
Tutor: Rajatheva, Rajatheva
Reviewer: Rajatheva, Rajatheva
Kapuruhamy Badalge, Shashika


The problem of max-min signal-to-interference plus noise ratio (SINR) for uplink transmission of cell-free massive multiple-input multiple-output (MIMO) system is considered. We assume that the system is employed with local minimum mean square error (L-MMSE) detection. The objective is to preserve user fairness by solving max-min rate optimization problem, by optimizing transmit power of each user equipment (UE) and weighting coefficients at central processing unit (CPU), subject to a transmit power constraint at each UE. This problem is not jointly convex. Hence, we decompose original problem into two subproblems, particularly for optimizing power allocation and weight coefficients. Then, we propose an iterative algorithm to solve these two subproblems alternately. Weight coefficient subproblem is solved in the form of generalized eigen value problem while power allocation subproblem is solved by approximating as geometric programming (GP) problem.

see all

Copyright information: © Chamalee Wickrama Arachchi, 2019. This publication is copyrighted. You may download, display and print it for your own personal use. Commercial use is prohibited.