Sökning: "belief propagation decoding"

Visar resultat 1 - 5 av 6 avhandlingar innehållade orden belief propagation decoding.

1. 1. Simplified Graphical Approaches for CDMA Multi-User Detection, Decoding and Power Control

   Författare :Peng Hui Tan; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; code-division multiple access; belief propagation; large system analysis; iterative decoding; multiuser detection; power control;

   Sammanfattning : The individual optimal detector for code-division multiple-access (CDMA) systems is based on the marginal a posteriori distribution of the transmitted bits. The marginalization is in general hard since a summation is required, which grows exponentially in scope with the number of active users. LÄS MER

3. 2. Finite-Length Scaling Laws for Spatially-Coupled LDPC Codes

   Författare :Roman Sokolovskii; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; belief propagation decoding; spatially-coupled LDPC codes; window decoding; codes-on-graphs; finite-length code performance;

   Sammanfattning : This thesis concerns predicting the finite-length error-correcting performance of spatially-coupled low-density parity-check (SC-LDPC) code ensembles over the binary erasure channel. SC-LDPC codes are a very powerful class of codes; their use in practical communication systems, however, requires the system designer to specify a considerable number of code and decoder parameters, all of which affect both the code’s error-correcting capability and the system’s memory, energy, and latency requirements. LÄS MER

4. 3. On Probabilistic Shaping and Learned Decoders with Application to Fiber-Optic Communications

   Författare :Andreas Buchberger; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Error correcting codes; learned decoders; machine learning; iterative decoding; probabilistic shaping; fiber-optic communications; pruning;

   Sammanfattning : We live in an ubiquitously connected world whose backbone are optical fibers. Achieving high spectral efficiencies and hence high transmission rates requires a careful combination of forward error correction (FEC) and higher-order modulation. This is referred to as coded modulation. LÄS MER

5. 4. Sparse Codes on Graphs with Convolutional Code Constraints

   Författare :Muhammad Umar Farooq; Kommunikationsteknologi; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Braided codes; Density evolution; Serially concatenated codes; Spatially coupled codes; Generalized LDPC codes; threshold saturation; Turbo codes;

   Sammanfattning : Modern coding theory is based on the foundation of the sparse codes on graphs, such as the low-density parity-check (LDPC) codes, and the turbo-like codes (TCs) with component convolutional codes. The success of the LDPC codes and the TCs lies in their ability to perform low-complexity iterative message passing decoding procedures. LÄS MER

7. 5. Spatially Coupled Turbo-Like Codes

   Författare :Saeedeh Moloudi; Kommunikationsteknologi; []
   Nyckelord :;

   Sammanfattning : The focus of this thesis is on proposing and analyzing a powerful class of codes on graphs---with trellis constraints---that can simultaneously approach capacity and achieve very low error floor. In particular, we propose the concept of spatial coupling for turbo-like code (SC-TC) ensembles and investigate the impact of coupling on the performance of these codes. LÄS MER