Papers for

satellite communication system designers

Papers whose findings have a practical use for this group, as judged from the abstract. Open a paper to read what it means in practice.

Improved decoding method lowers errors for polar codes with CRC

PMR-Aided Shifted-Pruning SCL-Flip Decoding for CRC-Aided Polar Codes

Abstract: We propose a posterior-mass rescue (PMR)-aided shifted-pruning SCL-flip decoder for CRC-aided polar codes. After CRC-aided SCL (CA-SCL) and differential-metric shifted-pruning recovery fail to find a CRC-valid candidate, PMR locally continues discarded prefixes stored during the initial CA-SCL pass, ranked by estimated posterior mass, without increasing the shifted-pruning retry budget. Simulation results for a (128, 64) code with the Reed-Muller (RM) rate profile and a (256, 128) code with the polarization-weight (PW) rate profile, both using an 11-bit CRC, show lower observed FER than SCLF-Diff (T = 15) and the considered literature baselines under the evaluated recovery budgets, with observed FER close to that of SCLF-Diff (T = 20). At the reported moderate and high SNRs, the average reconstruction-aware path-step count is within a few percent of that of SCLF-Diff (T = 20), while at 2.0 dB it is 9.4% and 4.3% higher for the two codes, respectively. The proposed decoder also has a larger worst-case path-step bound.

Mon 19 OctInformation Theory
The gist
Polar codes are a way to send data that helps correct errors during transmission, often used with a technique called CRC for checking accuracy. The authors introduce a new decoding method that tries more promising options from earlier attempts to fix errors without needing much extra effort. This method showed fewer mistakes in simulations compared to similar existing approaches, especially in moderate to high-quality signal conditions. Although it can sometimes require more processing steps in the worst cases, overall it offers better error correction for certain code lengths and profiles.
Open → 2610.25644v1

High rate adaptive LDPC codes with short memory for better data reliability

Design of a Family of Rate-Adaptive LDPC Convolutional Codes with Short Constraint Length

Abstract: This paper studies the design of some high-rate, adaptive, low-density parity-check (LDPC) convolutional codes with short constraint length, based on interleaved parity-check polynomials. Starting from some known results regarding the selection of polynomials that yield codes free of short cycles in the associated Tanner graphs, we propose some new constructions based on Golomb rulers, along with relaxed variants that do not strictly satisfy the Golomb ruler condition, but retain similar structural properties. The result is a family of rate-adaptive code constructions with code rates of the form $R=(n_0-1)/n_0$. Conditions for the absence of length-4 cycles are derived, together with upper bounds on the free distance that are met in all considered examples.

Thu 15 OctInformation Theory
The gist
Communication systems need codes to detect and correct errors in transmitted data. This paper presents a way to design special error-correcting codes called LDPC convolutional codes that can adjust their rate and have short memory to simplify processing. The authors use mathematical tools called Golomb rulers to build these codes while avoiding certain problems in their decoding structure. Their designs ensure good error correction performance and flexibility in how much data is sent versus how much quality is guaranteed.
Open → 2610.22231v1