Sökning: "turbo codes"

Visar resultat 1 - 5 av 26 avhandlingar innehållade orden turbo codes.

  1. 1. On the Design of Turbo Codes

    Författare :Johan Hokfelt; Institutionen för elektro- och informationsteknik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Channel coding; concatenated codes; convolutional codes; iterative decoding; interleaver design; trellis termination; Electronics; Turbo codes; Elektronik;

    Sammanfattning : This thesis is about Turbo codes - codes constructed via parallel concatenation of two recursive convolutional encoders linked by an interleaver. The focus of the work is on the understanding and design of Turbo codes. LÄS MER

  2. 2. Designing Space-Time Codes Using Orthogonal Designs

    Författare :Girish Ganesan; Thomas Marzetta; Uppsala universitet; []
    Nyckelord :ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Space-time codes; Orthogonal designs; Amicable orthogonal designs; Differential detection; Trellis codes; Turbo codes; Signal processing; Signalbehandling; Signal Processing; Signalbehandling;

    Sammanfattning : This thesis deals with coding schemes for systems with multiple transmit antennas. The problem of finding optimal transmission schemes for the case when the transmitter knows the channel and the case when the transmitter does not know the channel are considered. LÄS MER

  3. 3. Iteratively Decodable Convolutional Codes: Analysis and Implementation Aspects

    Författare :Alberto Jimenez Feltström; Institutionen för elektro- och informationsteknik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; systems theory; Informatics; Intersymbol Interference; BPSK; Product Codes; Braided Codes; Low-Density Parity-Check Codes; Convolutional Codes; Iterative Decoding; Informatik; systemteori; Systems engineering; computer technology; Data- och systemvetenskap;

    Sammanfattning : This thesis addresses the theory and implementation aspects of iteratively decodable codes. Iteratively decodable codes include, in particular, Gallager's regular low-density parity-check (LDPC) codes, Tanner's generalized LDPC (GLDPC) codes, turbo codes due to Berrou et. al. and expander codes. LÄS MER

  4. 4. Turbo Codes and Channel Estimation in Wireless Systems

    Författare :Bartosz Mielczarek; Chalmers University of Technology; []
    Nyckelord :adaptive coding; turbo codes; PSAM; timing offset; BCJR algorithm; synchronization; channel estimation; phase offset; Wiener filters; unequal error protection; OFDM;

    Sammanfattning : This thesis focuses on practical implementation issues of turbo codes with imperfectly estimated fading wireless channels and limited code length. Channel estimation can be divided into estimation of static parameters, such as constant timing and phase offset, and dynamic parameters, such as fading channel amplitudes. LÄS MER

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

    Författare :Pål Frenger; Chalmers University of Technology; []
    Nyckelord :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