Sökning: "low-density codes"
Visar resultat 1 - 5 av 27 avhandlingar innehållade orden low-density codes.
1. Low-density parity-check codes : unequal error protection and reduction of clipping effects
Sammanfattning : The invention of low-density parity-check (LDPC) codes made reliable communication possible at transmission rates very close to the theoretical limit predicted by Shannon. However, communication close to the Shannon limit requires very long codes and results in long delay and high encoder and decoder complexity. LÄS MER
2. Analysis of Some Convolutional Coding Constructions
Sammanfattning : This thesis focuses on different convolutional coding constructions for digital communication systems, and on methods to analyze these constructions. The work presented in the thesis can be divided into three main areas; error probability bounds for convolutional codes, analysis of multilevel modulation, and investigation of low-density parity-check convolutional codes. LÄS MER
3. Codes on Graphs and More
Sammanfattning : Modern communication systems strive to achieve reliable and efficient information transmission and storage with affordable complexity. Hence, efficient low-complexity channel codes providing low probabilities for erroneous receptions are needed. LÄS MER
4. Iteratively Decodable Convolutional Codes: Analysis and Implementation Aspects
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
5. Sparse Codes on Graphs with Convolutional Code Constraints
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