Upper Bounds on the Rate of LDPC Codes
نویسنده
چکیده
منابع مشابه
Upper Bounds on the Rate of Ramdomly Constructed LDPC Codes for a Class of Markov Channels
We consider a class of finite-state Markov channels, in which channel behaves as a Binary Symmetric Channel (BSC) in each state. We find upper bounds on the rate of LDPC codes for reliable communication over this class of Markov channels. However, the results hold only for the construction of LDPC codes in which a code is selected randomly from a given ensemble of codes.
متن کاملOn Achievable Rates and Complexity of LDPC Codes for Parallel Channels with Application to Puncturing
This paper considers the achievable rates and decoding complexity of low-density parity-check (LDPC) codes over statistically independent parallel channels. The paper starts with the derivation of bounds on the conditional entropy of the transmitted codeword given the received sequence at the output of the parallel channels; the component channels are considered to be memoryless, binary-input, ...
متن کاملFinite-Dimensional Bounds on Zm and Binary LDPC Codes with Belief Propagation Decoders: Stability Conditions on Zm Codes and Cutoff Rate Analysis on Non-symmetric Binary Channels
This paper focuses on finite-dimensional upper and lower bounds on decodable thresholds of Z m and binary LDPC codes, assuming belief propagation decoding on memoryless channels. Two noise measures will be considered: the Bhattacharyya noise parameter and the soft bit value for a MAP decoder on the uncoded channel. For Z m LDPC codes, an iterative m-dimensional bound is derived for m-ary-input/...
متن کاملExhausting Error-Prone Patterns in LDPC Codes
It is proved in this work that exhaustively determining bad patterns in arbitrary, finite low-density paritycheck (LDPC) codes, including stopping sets for binary erasure channels (BECs) and trapping sets (also known as nearcodewords) for general memoryless symmetric channels, is an NP-complete problem, and efficient algorithms are provided for codes of practical short lengths n ≈ 500. By explo...
متن کاملUpper Bounds on the Minimum Distance of Quasi-Cyclic LDPC codes Revisited
In this paper we investigate the minimum code distance of QC LDPC codes [1], [2], [3]. These codes form an important subclass of LDPC codes [4], [5]. These codes also are a subclass of protograph-based LDPC codes [6]. QC LDPC codes can be easily stored as their parity-check matrices can be easily described. Besides such codes have efficient encoding [7] and decoding [8] algorithms. All of these...
متن کامل