Lê, Viêt HoàngViêt HoàngLêBrüggmann, JasperJasperBrüggmannMohr, PhilippPhilippMohrBauch, GerhardGerhardBauch2026-06-032026-06-032026IEEE International Conference on Communications (ICC) 2026https://hdl.handle.net/11420/63311Block Markov Superposition Transmission (BMST) codes are a class of spatially coupled codes, that achieve excellent error correction performance via superposition of simple constituent codes. A BMST encoder consists of an outer basic code and an inner rate-one block-convolutional shift register. The resulting graph representation of the encoder allows slidingwindow decoding, similarly to spatially coupled Low-Density Parity-Check codes. This paper proposes a method to reduce the decoding complexity by adjusting the step size of the sliding window. Furthermore, a low-complexity parity-check-based early termination criterion is introduced, which can be universally applied to recursive BMST structures.enhttp://rightsstatements.org/vocab/InC/1.0/Spatially coupled codesblock Markov superposition transmissionsliding-window decodingComputer Science, Information and General Works::006: Special computer methodsTechnology::621: Applied Physics::621.3: Electrical Engineering, Electronic Engineering::621.38: Electronics, Communications EngineeringConference Paperhttps://doi.org/10.15480/882.1723610.15480/882.17236Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting / republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to server or lists, or reuse of any copyrighted component of this work in other works.