On Construction of Moderate-Length LDPC Codes over Correlated Erasure Channels

Abstract

The design of moderate-length erasure correcting low-density parity-check (LDPC) codes over correlated erasure channels is considered. Although the asymptotic LDPC code design remains the same as for a memoryless erasure channel, robustness to the channel correlation shall be guaranteed for the finite length LDPC code. This further requirement is of great importance in several wireless communication scenarios where packet erasure correcting codes represent a simple countermeasure for correlated fade events (e.g., in mobile wireless broadcasting services) and where the channel coherence time is often comparable with the code length. In this paper, the maximum tolerable erasure burst length (MTBL) is adopted as a simple metric for measuring the code robustness to the channel correlation. Correspondingly, a further step in the code construction is suggested, consisting of improving the LDPC code MTBL. Numerical results conducted over a Gilbert erasure channel, under both iterative and maximum likelihood decoding, highlight both the importance of the MTBL improvement in the finite-length code construction and the possibility to tightly approach the performance of maximum distance separable codes.

Windowed Decoding of Protograph-Based LDPC Convolutional Codes Over Erasure Channels

“…Therefore, when a burst occurs, it is likely to resemble a single burst in a codeword, and in this case we know that the code C 2 is stronger than C 1 . Also note the significant gap between the BP decoder performance and the Singleton C ER bound, suggesting that unlike some moderate length LDPC block codes with ML decoding [38], LDPC-CC are far from achieving MDS performance with BP or windowed decoding.…”

Statistical properties of single-mode fiber coupling of satellite-to-ground laser links partially corrected by adaptive optics

“…Fade duration distribution: The AFD is an important parameter for the design of efficient numerical fading-mitigation techniques such as interleaving and forward error-correction codes on bursty channels. The AFD can be used to infer the distribution of the fades' duration, the latter being essential to the evaluation of coded error probability on correlated fading channels without interleaving or with imperfect interleaving [39][40][41]. In [42], these distributions were obtained from experimental links data and compared to those generated by a twostate Markov (Gilbert-Erasure) model.…”

Maritime Mobile Optical-Propagation Channel Measurements

“…The results obtained from this work can be used for the calculation of atmosphere fading losses as it is described in [2]. Further results are important for the development of channel-models, or the design of fading mitigation or error protection schemes as described in [9].…”

“…How this is done for the case of LN distributed power is described in [2] and should not be repeated in here. Additionally the knowledge about the channel correlation is essential for the design of powerful error protection schemes, because as described in [9] channel correlation drives the performance of forward error correction codes. In the past a lot of work has been done to estimate the performance of linkpaths over land as for example reported in [1], [3], [10].…”