Ändra sökning
RefereraExporteraLänk till posten
Permanent länk

Direktlänk
Referera
Referensformat
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
Design and performance of optimized relay mappings
KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori. KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre.
KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori. KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre.ORCID-id: 0000-0002-7926-5081
2010 (Engelska)Ingår i: IEEE Transactions on Communications, ISSN 0090-6778, E-ISSN 1558-0857, Vol. 58, nr 9, s. 2718-2724Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

We look at the three-node relay channel and the transmission of an information symbol from the source node to the destination node. We let the relay be a memoryless function and formulate necessary conditions for the optimality of the relay mapping and the detector. Based on these, we propose a design algorithm to find relay mappings such that the symbol error rate at the destination is minimized. The optimized relay mappings are illustrated for different scenarios and the dependency between the relay mapping and the link qualities is discussed in detail. Furthermore, the performance is compared with existing schemes, such as detect-and-forward, amplify-and-forward, and estimate-and-forward. It is shown that there is a significant gain in terms of decreased symbol error rate if the optimized relay mapping is used.

Ort, förlag, år, upplaga, sidor
2010. Vol. 58, nr 9, s. 2718-2724
Nyckelord [en]
Cooperative transmission, relay channel, relay mapping, modulation, detection, sensor networks.
Nationell ämneskategori
Telekommunikation
Identifikatorer
URN: urn:nbn:se:kth:diva-9696DOI: 10.1109/TCOMM.2010.071410.080475ISI: 000283588700027Scopus ID: 2-s2.0-77956929922OAI: oai:DiVA.org:kth-9696DiVA, id: diva2:126996
Anmärkning
QC 20110207Tillgänglig från: 2008-11-27 Skapad: 2008-11-27 Senast uppdaterad: 2017-12-14Bibliografiskt granskad
Ingår i avhandling
1. Low-delay sensing and transmission in wireless sensor networks
Öppna denna publikation i ny flik eller fönster >>Low-delay sensing and transmission in wireless sensor networks
2008 (Engelska)Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
Abstract [en]

With the increasing popularity and relevance of ad-hoc wireless sensor networks, cooperative transmission is more relevant than ever. In this thesis, we consider methods for optimization of cooperative transmission schemes in wireless sensor networks. We are in particular interested in communication schemes that can be used in applications that are critical to low-delays, such as networked control, and propose suitable candidates of joint source-channel coding schemes. We show that, in many cases, there are significant gains if the parts of the system are jointly optimized for the current source and channel. We especially focus on two means of cooperative transmission, namely distributed source coding and relaying.

In the distributed source coding case, we consider transmission of correlated continuous sources and propose an algorithm for designing simple and energy-efficient sensor nodes. In particular the cases of the binary symmetric channel as well as the additive white Gaussian noise channel are studied. The system works on a sample by sample basis yielding a very low encoding complexity, at an insignificant delay. Due to the source correlation, the resulting quantizers use the same indices for several separated intervals in order to reduce the quantization distortion.

For the case of relaying, we study the transmission of a continuous Gaussian source and the transmission of an uniformly distributed discrete source. In both situations, we propose design algorithms to design low-delay source-channel and relay mappings. We show that there can be significant power savings if the optimized systems are used instead of more traditional systems. By studying the structure of the optimized source-channel and relay mappings, we provide useful insights on how the optimized systems work. Interestingly, the design algorithm generally produces relay mappings with a structure that resembles Wyner-Ziv compression.

Serie
Trita-EE, ISSN 1653-5146 ; 2008:059
Nyckelord
Cooperative communication, wireless sensor networks, low-delay transmission, joint source-channel coding, estimation, quantization
Nationell ämneskategori
Telekommunikation
Identifikatorer
urn:nbn:se:kth:diva-9697 (URN)
Presentation
2008-12-18, Q26, Osquldas väg 6B, KTH, Stockholm, 13:15 (Engelska)
Opponent
Handledare
Tillgänglig från: 2008-11-28 Skapad: 2008-11-27 Senast uppdaterad: 2011-11-10
2. Low-delay sensing and transmission
Öppna denna publikation i ny flik eller fönster >>Low-delay sensing and transmission
2011 (Engelska)Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
Abstract [en]

This thesis studies cooperative sensing and transmission in the context ofwireless sensor networks (WSNs). We especially focus on two means of cooperative sensing and transmission, namely, distributed source coding and relaying. We consider systems where the usefulness of the measured data is dependent on how old the data is and we therefore need low-delay transmission schemes. At first sight, the low-delay criterion may seem to be of little relevance, but it is this aspect in particular that distinguishes this thesis from many of the existing communication theoretic results, which often are asymptotic in the block lengths. The thesis is composed of an introductory part, discussing the fundamentals of communication theory and how these are related to the requirements of WSNs, followed by a part where the results of the thesis are reported in Papers A-H.

Papers A-D study different scenarios for distributed source-channel coding. In Paper A, we consider transmission of correlated continuous sources and propose an iterative algorithm for designing simple and energy-efficient sensor nodes. In particular the cases of the binary symmetric channel as well as the additive white Gaussian noise channel are studied. In Paper B, the work is extended to channels with interference and it is shown that also in this case there can be significant power savings by performing a joint optimization of the system.Papers C and D use a more structured approach and propose side-information-aware source-channel coding strategies using lattices and sinusoids.

In Paper E, we apply the methods we have used in joint source-channel coding to the famous Witsenhausen counterexample. By using a relatively simple iterative algorithm, we are able to demonstrate the best numerical performance known to date.

For the case of systems with relays, we study the transmission of a continuous Gaussian source and the transmission of an uniformly distributed discrete source. In both situations, we propose algorithms to design low-delay source-channel and relay mappings. By studying the structure of the optimized source-channel and relay mappings, we provide useful insights into how the optimized systems work. These results are reported in Papers F and G.

In Paper H, we finally consider sum-MSE minimization for the Gaussian multiple-input, multiple-output broadcast channel. By using recently discovered properties of this problem, we derive a closed-form expression for the optimal power allocation in the two-user scenario and propose a conceptually simple and efficient algorithm that handles an arbitrary number of users.

Throughout the thesis we show that there are significant gains if the parts of the system are jointly optimized for the source and channel statistics. All methods that are considered in this thesis yield very low coding and decoding delays. In general, nonlinear mappings outperform linear mappings for problems where there is side-information available. Another contribution of this thesis is visualization of numerically optimized systems that can be used as inspiration when structured low-delay systems are designed.

Ort, förlag, år, upplaga, sidor
Stockholm: KTH Royal Institute of Technology, 2011. s. xii, 30
Serie
Trita-EE, ISSN 1653-5146 ; 2011:039
Nyckelord
Cooperative communication, wireless sensor networks, low-delay transmission, joint source-channel coding, distributed source coding, estimation, quantization
Nationell ämneskategori
Telekommunikation
Identifikatorer
urn:nbn:se:kth:diva-33404 (URN)978-91-7415-983-7 (ISBN)
Disputation
2011-05-26, Hörsal F3, Lindstedtsvägen 26, KTH, Stockholm, 13:15 (Engelska)
Opponent
Handledare
Forskningsfinansiär
ICT - The Next Generation
Anmärkning
The author changed name from Johannes Karlsson to Johannes Kron in January 2011. QC 20110512Tillgänglig från: 2011-05-12 Skapad: 2011-05-05 Senast uppdaterad: 2011-10-30Bibliografiskt granskad

Open Access i DiVA

Fulltext saknas i DiVA

Övriga länkar

Förlagets fulltextScopus

Personposter BETA

Skoglund, Mikael

Sök vidare i DiVA

Av författaren/redaktören
Karlsson, JohannesSkoglund, Mikael
Av organisationen
KommunikationsteoriACCESS Linnaeus Centre
I samma tidskrift
IEEE Transactions on Communications
Telekommunikation

Sök vidare utanför DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetricpoäng

doi
urn-nbn
Totalt: 89 träffar
RefereraExporteraLänk till posten
Permanent länk

Direktlänk
Referera
Referensformat
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf