A Phenomenological Study on Threshold Improvement via Spatial Coupling

Abstract

Kudekar et al. proved an interesting result in low-density parity-check (LDPC) convolutional codes: The belief-propagation (BP) threshold is boosted to the maximum-a-posteriori (MAP) threshold by spatial coupling. Furthermore, the authors showed that the BP threshold for code-division multiple-access (CDMA) systems is improved up to the optimal one via spatial coupling. In this letter, a phenomenological model for elucidating the essence of these phenomenon, called threshold improvement, is proposed. The main result implies that threshold improvement occurs for spatially-coupled general graphical models.

re-submitted to IEICE Trans. Fundamentals

References in corpus (1)

• Threshold Saturation via Spatial Coupling: Why Convolutional LDPC Ensembles Perform so well over the BEC

Cited by in corpus (12)

• Threshold Saturation for Spatially-Coupled LDPC and LDGM Codes on BMS Channels
• A Simple Proof of Maxwell Saturation for Coupled Scalar Recursions
• Performance Improvement of Iterative Multiuser Detection for Large Sparsely-Spread CDMA Systems by Spatial Coupling
• Capacity-achieving Spatially Coupled Sparse Superposition Codes with AMP Decoding
• Wave-Like Solutions of General One-Dimensional Spatially Coupled Systems
• Spatially Coupled Ensembles Universally Achieve Capacity under Belief Propagation
• A Generalization of Threshold Saturation: Application to Spatially Coupled BICM-ID
• Thresholds of Spatially Coupled Systems via Lyapunov's Method
• Accelerating Iterative Detection for Spatially Coupled Systems by Collaborative Training
• A Potential Theory of General Spatially-Coupled Systems via a Continuum Approximation
• Iterative LMMSE Channel Estimation, Multiuser Detection, and Decoding via Spatial Coupling
• Spatially-Coupled MacKay-Neal Codes Universally Achieve the Symmetric Information Rate of Arbitrary Generalized Erasure Channels with Memory