liu.seSearch for publications in DiVA
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • oxford
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Blind Channel Equalization for Shortwave Digital Radio Communications
Linköping University, Department of Electrical Engineering, Automatic Control.
2020 (English)Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesisAlternative title
Blind kanalutjämning för digital kortvågskommunikation (Swedish)
Abstract [en]

In this thesis the concept of Blind Channel Equalization has been examined and algorithms suitable to blindly equalize the channel are presented and evaluated on simulated data. The concept of blind equalization is to equalize a communica- tions channel without relying on a training sequence or pilot tone, which may be either unknown to the receiver or not exist at all. In total, seven blind equaliza- tion algorithms have been implemented, these are the: lms-cma (Constant Modu- lus Algorithm), rls-cma, mma (Multi Modulus Algorithm), rca (Reduced Constel- lation Algorithm), cna-6 (Constant Norm Algorithm), lms-dfe (Decision Feedback Equalization) and rls-dfe. The equalizers are designed as adaptive fir-filters that are recursively updated by either an lms- or rls-algorithm, according to a cost function specified by the chosen algorithm with the aim to appoximate the inverse h−1 of the communications channel h. Thanks to the recursive update the algorithms can easily be implemented either in offline or online systems.

The results show that the rls-algorithms offer shorter convergence times and over all better performance than its lms counterparts. If the signal constellation is known by the receiver in advance the rls-dfe offers the best channel tracking ability, resulting in the lowest symbol error rate.The rls-cma offers the roughly the same mseR -performance (mean square error from the equalizer output to the closest radius of the constellation points) but it lacks the ability to handle the doppler shift as well as the rls-dfe does. The results also show that the mma, cna-6 and rca-algorithms do not offer any better performance than the more commonly used and studied lms-cma algorithm.

When the receiver incorrectly assumes the signal constellation, it can identify the correct constellation. Test results show that the rls-cma is especially good at amplitde recovery, while the rls-dfe is suitable to recover the phase of the signal. Lastly the rca is useful to recover psk-4 modulated signals as its cost function match the psk-4 constellation.

Place, publisher, year, edition, pages
2020. , p. 80
Keywords [en]
Blind Channel Equalization, Equalization, adaptive filter, radio communication
Keywords [sv]
Blind kanalutjämning, kanalutjämning, adaptivt filter, radiokommunikation
National Category
Control Engineering Signal Processing
Identifiers
URN: urn:nbn:se:liu:diva-164117ISRN: LiTH-ISY-EX--20/5279--SEOAI: oai:DiVA.org:liu-164117DiVA, id: diva2:1412376
External cooperation
FOI
Subject / course
Automatic Control
Presentation
2020-02-27, Linköping, 14:00 (Swedish)
Supervisors
Examiners
Available from: 2020-03-06 Created: 2020-03-05 Last updated: 2020-03-06Bibliographically approved

Open Access in DiVA

fulltext(42237 kB)45 downloads
File information
File name FULLTEXT01.pdfFile size 42237 kBChecksum SHA-512
43b0a56a290689fc74b47ac80bb0ad0eae45a4510acfb4f619cae238e1f4f0813545f1f47947ff37ca346c356644ceb0291ed1b063366e4a80f8fe779edc43a1
Type fulltextMimetype application/pdf

Search in DiVA

By author/editor
Busk, Tomas
By organisation
Automatic Control
Control EngineeringSignal Processing

Search outside of DiVA

GoogleGoogle Scholar
Total: 45 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

urn-nbn

Altmetric score

urn-nbn
Total: 102 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • oxford
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf