Sökning: "nested codes"

Visar resultat 1 - 5 av 7 avhandlingar innehållade orden nested codes.

  1. 1. Multirate Codes and Multicarrier Modulation for Future Communication Systems

    Författare :Pål Frenger; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; channel estimation; code-spread CDMA; DS-CDMA; convolutional codes; interference cancellation; nested convolutional codes; multicarrier modulation; optimum distance spectrum ODS ; rate-compatible punctured convolutional codes RCPC-codes ; OFDM; turbo decoding; rate matching; parallel combinatory signaling; Rayleigh fading;

    Sammanfattning : In this thesis, new detection and modulation methods for multicarrier systems are presented. The proposed multicarrier detectors are based on feedback of previously detected symbols and the idea is to exploit the correlation, both in time between consecutive symbols, and in frequency between neighboring sub-carriers. LÄS MER

  3. 2. Coding, Decoding and Multiuser Detection for Wireless CommunicationsCoding, Decoding and Multiuser Detection for Wireless Communications

    Författare :Pål Orten; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; direct-sequence code division multiple access DS-CDMA ; sequential decoding; Rayleigh fading; multirate DS-CDMA; optimum distance spectrum; rate matching; rate compatible punctured convolutional codes; multiuser detection; nested codes;

    Sammanfattning : In the strive for making the Universal Mobile Telecommunication System(UMTS) a reality, concepts and techniques are to be developed which canprovide both high system capacity and sufficient quality for the increasingnumber of mobile users. To obtain these objectives, powerful and flexibleerror control coding is needed, as well as efficient means for many usersto share the same commmication medium. LÄS MER

  4. 3. Channel Coding and Multiuser Detection for CDMA and Wireless Communications

    Författare :Pål Orten; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; rate compatible punctured convolutional RCPC codes; optimum distance spectrum ODS ; low-rate convolutional codes; interference cancellation; code-division multiple-access CDMA ; sequential decoding; automatic repeat request ARQ ; multiuser detection; maximum free distance MFD ; nested convolutional codes; tailbiting; rate matching;

    Sammanfattning : Next generation wireless communication systems will require support for many different applications as well as improved quality compared to existing second generation systems like GSM (Global System for Mobile communications). Since there will be more users and higher data rates, the capacity must also be increased. LÄS MER

  5. 4. Coding Strategies for Compress-and-Forward Relaying

    Författare :Ricardo Blasco-Serrano; Mikael Skoglund; Ragnar Thobaben; Joerg Kliewer; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Telecommunication theory; Telekommunikationsteori;

    Sammanfattning : The deployment of large communication networks with many autonomous devices has opened new possibilities for transmission. In particular cooperation among the different nodes has been identified as an enabling technology to satisfy the increasing demand of resources. LÄS MER

  7. 5. Insights from comorbidity into multiple sclerosis aetiology and outcomes

    Författare :Homayoun Roshanisefat; Karolinska Institutet; Karolinska Institutet; []
    Nyckelord :Multiple Sclerosis;

    Sammanfattning : Aim: The overall aim of this research was to investigate the nature of the comorbidities in multiple sclerosis (MS) in four large population-based studies. The first study assessed whether the diagnosis underlying appendicectomy is a useful marker of MS risk. LÄS MER