Change search
ReferencesLink to record
Permanent link

Direct link
Coordinated MIMO Precoder EvaluationBased on Measurement in IndoorEnvironment
KTH, School of Electrical Engineering (EES), Signal Processing.
2013 (English)Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
Abstract [en]

In this thesis, we investigate the performance of the coordinated MIMO precoders, using measured channels in indoorvenvironment. Instead of simulated radio propagationvconditions, measured channels are used to evaluate the precoder performance for real-world channels. Our measurement campaign includes several scenarios such as femtocell and “heterogeneous” networks. The study results illustrate that the precoders could reduce the interference significantly and support a high system throughput especially over high SNR where interference is dominant.

Degree of freedom (DoF) is defined as the maximum number of data stream that could independently coordinate to be transmitted interference-free. Theoretically, the precoders could support 1 DoF per user, while DoF of uncoordinated transmission is 0 per user. Interference Alignment(IA) study arises from information theory of DoF in the interference channel (IC). Three precoding algorithms are investigated to align the interference: maximum sum rate, maxSINR and minWLI. Considering the distributed precoder methods, “maxSINR” always performs better than “minWLI”. Since it tries to maximize the user’s SINR instead of only repressing the interference as “minWLI” does. While “maximum sum rate” is not good at finding an IA like solution that scales well at high SNR. However “maximum sum rate” converges faster than “maxSINR” and “minWLI”.

Our study about IA feasibility shows that precoding jointly over two subcarriers, using so called frequency extensions, allows 4 users to communicate interference-freeover a 2 × 2 MIMO IC. Without frequency extensions, only 3 users can communicate interference-free.

Place, publisher, year, edition, pages
2013. , 62 p.
EES Examensarbete / Master Thesis, XR-EE-SB 2013:004
National Category
Electrical Engineering, Electronic Engineering, Information Engineering
URN: urn:nbn:se:kth:diva-121045OAI: diva2:616514
Subject / course
Signal Processing
Educational program
Master of Science - Wireless Systems
2013-02-18, 09:30 (English)
Available from: 2013-05-03 Created: 2013-04-17 Last updated: 2013-05-03Bibliographically approved

Open Access in DiVA

fulltext(14749 kB)243 downloads
File information
File name FULLTEXT01.pdfFile size 14749 kBChecksum SHA-512
Type fulltextMimetype application/pdf

Search in DiVA

By author/editor
Zhu, Xiaoqian
By organisation
Signal Processing
Electrical Engineering, Electronic Engineering, Information Engineering

Search outside of DiVA

GoogleGoogle Scholar
Total: 243 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Total: 198 hits
ReferencesLink to record
Permanent link

Direct link