A New Family of Low-Complexity STBCs for Four Transmit Antennas

Handle URI:
http://hdl.handle.net/10754/263752
Title:
A New Family of Low-Complexity STBCs for Four Transmit Antennas
Authors:
Ismail, Amr; Fiorina, Jocelyn; Sari, Hikmet
Abstract:
Space-Time Block Codes (STBCs) suffer from a prohibitively high decoding complexity unless the low-complexity decodability property is taken into consideration in the STBC design. For this purpose, several families of STBCs that involve a reduced decoding complexity have been proposed, notably the multi-group decodable and the fast decodable (FD) codes. Recently, a new family of codes that combines both of these families namely the fast group decodable (FGD) codes was proposed. In this paper, we propose a new construction scheme for rate-1 FGD codes for 2^a transmit antennas. The proposed scheme is then applied to the case of four transmit antennas and we show that the new rate-1 FGD code has the lowest worst-case decoding complexity among existing comparable STBCs. The coding gain of the new rate-1 code is optimized through constellation stretching and proved to be constant irrespective of the underlying QAM constellation prior to normalization. Next, we propose a new rate-2 FD STBC by multiplexing two of our rate-1 codes by the means of a unitary matrix. Also a compromise between rate and complexity is obtained through puncturing our rate-2 FD code giving rise to a new rate-3/2 FD code. The proposed codes are compared to existing codes in the literature and simulation results show that our rate-3/2 code has a lower average decoding complexity while our rate-2 code maintains its lower average decoding complexity in the low SNR region. If a time-out sphere decoder is employed, our proposed codes outperform existing codes at high SNR region thanks to their lower worst-case decoding complexity.
KAUST Department:
Computer, Electrical and Mathematical Sciences and Engineering (CEMSE) Division; Communication Theory Lab
Publisher:
IEEE
Journal:
Transactions on Wireless Communications
Issue Date:
29-Dec-2012
DOI:
10.1109/TWC.2013.011513.120517
Type:
Article
ISSN:
1536-1276
Appears in Collections:
Articles; Communication Theory Lab; Computer, Electrical and Mathematical Sciences and Engineering (CEMSE) Division

Full metadata record

DC FieldValue Language
dc.contributor.authorIsmail, Amren
dc.contributor.authorFiorina, Jocelynen
dc.contributor.authorSari, Hikmeten
dc.date.accessioned2012-12-29T11:23:27Z-
dc.date.available2012-12-29T11:23:27Z-
dc.date.issued2012-12-29en
dc.identifier.issn1536-1276en
dc.identifier.doi10.1109/TWC.2013.011513.120517en
dc.identifier.urihttp://hdl.handle.net/10754/263752en
dc.description.abstractSpace-Time Block Codes (STBCs) suffer from a prohibitively high decoding complexity unless the low-complexity decodability property is taken into consideration in the STBC design. For this purpose, several families of STBCs that involve a reduced decoding complexity have been proposed, notably the multi-group decodable and the fast decodable (FD) codes. Recently, a new family of codes that combines both of these families namely the fast group decodable (FGD) codes was proposed. In this paper, we propose a new construction scheme for rate-1 FGD codes for 2^a transmit antennas. The proposed scheme is then applied to the case of four transmit antennas and we show that the new rate-1 FGD code has the lowest worst-case decoding complexity among existing comparable STBCs. The coding gain of the new rate-1 code is optimized through constellation stretching and proved to be constant irrespective of the underlying QAM constellation prior to normalization. Next, we propose a new rate-2 FD STBC by multiplexing two of our rate-1 codes by the means of a unitary matrix. Also a compromise between rate and complexity is obtained through puncturing our rate-2 FD code giving rise to a new rate-3/2 FD code. The proposed codes are compared to existing codes in the literature and simulation results show that our rate-3/2 code has a lower average decoding complexity while our rate-2 code maintains its lower average decoding complexity in the low SNR region. If a time-out sphere decoder is employed, our proposed codes outperform existing codes at high SNR region thanks to their lower worst-case decoding complexity.en
dc.language.isoenen
dc.publisherIEEEen
dc.subjectSpace-time block codesen
dc.subjectlow-complexity decodable codesen
dc.subjectconditional detectionen
dc.subjectnon-vanishing determinanten
dc.titleA New Family of Low-Complexity STBCs for Four Transmit Antennasen
dc.typeArticleen
dc.contributor.departmentComputer, Electrical and Mathematical Sciences and Engineering (CEMSE) Divisionen
dc.contributor.departmentCommunication Theory Laben
dc.identifier.journalTransactions on Wireless Communicationsen
dc.eprint.versionPre-printen
dc.contributor.institutionElectronics and Communication Department, Faculty of Engineering, Cairo University, Cairo, Egypten
dc.contributor.affiliationKing Abdullah University of Science and Technology (KAUST)en
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