Performance of Sparse Code Multiple Access Communication System Based on Logarithmic Message Passing Algorithm and Low-Density Parity Check Code.

Saved in:
Bibliographic Details
Title: Performance of Sparse Code Multiple Access Communication System Based on Logarithmic Message Passing Algorithm and Low-Density Parity Check Code.
Authors: Moafaq, Mustafa Safwan1 Mustafa.S.Moafaq@uomustansiriyah.edu.iq, Al-Azawi, Maher K. Mahmood1
Source: Iraqi Journal for Electrical & Electronic Engineering. Dec2025, Vol. 21 Issue 2, p251-264. 14p.
Subjects: Low density parity check codes, Multiple access protocols (Computer network protocols), Error rates, Data transmission systems, Message passing (Computer science), Decoding algorithms
Abstract (English): The performance of Sparse Code Multiple Access (SCMA) communication system with Logarithmic Message Passing Algorithm (log-MPA) decoder is introduced. To boost the performance, a Low-Density Parity-Check Code LDPC is used together with Belief Propagation (BP) decoder. LDPC is chosen due to its sparsity property that complements the sparsity nature of SCMA for maximum efficiency and minimum complexity. Three distinct SCMA configurations are used. These are: A (4 x 4 x 6), B (4 x 16 x 6), and C (5 x 4 x 10) where the (K x M x V) are numbers of resources, codewords and users respectively. The performance of these configuration is shown in various channel conditions, various LDPC code rates and various numbers of SCMA iterations (NSCMA), to find the local minimum value of log-MPA. Simulation results showed that the LDPC greatly boosted the performance in mentioned configurations: In A configuration, a gain of 13 dB was observed. Configuration B experienced a substantial improvement of 23.5 dB, while C achieved a gain of 20.5 dB. Notably, configuration B stood out with the highest gain, attributed to LDPC's exceptional performance with high data rates, as the data transmitted in B was double that of A. [ABSTRACT FROM AUTHOR]
Abstract (Arabic): تركز المقالة على تقييم أداء أنظمة الاتصال متعددة الوصول باستخدام الشفرة المتفرقة (Sparse Code Multiple Access - SCMA) عند دمجها مع خوارزمية تمرير الرسائل اللوغاريتمية (Logarithmic Message Passing Algorithm - log-MPA) وتقنيات تصحيح الأخطاء باستخدام رموز التحقق من التماثل منخفضة الكثافة (Low-Density Parity Check - LDPC). تم تحليل ثلاث تكوينات لـ SCMA وهي (4×4×6)، (4×16×6)، و(5×4×10)، والتي تمثل على التوالي أعداد الموارد، كلمات الشفرة، والمستخدمين، وذلك تحت ظروف تلاشي رايلي (Rayleigh fading) وقناة الضوضاء البيضاء الغاوسية (AWGN)، مع تغير معدلات رموز LDPC وعدد التكرارات المختلفة لفك تشفير SCMA. أظهرت نتائج المحاكاة أن دمج رموز LDPC يحسن بشكل كبير من أداء معدل خطأ البت (Bit Error Rate - BER)، حيث تم ملاحظة مكاسب تصل إلى 23.5 ديسيبل، خاصة في سيناريوهات معدلات البيانات العالية، في حين تقلل خوارزمية log-MPA من تعقيد عملية فك التشفير مقارنة بالطرق التقليدية. تسلط الدراسة الضوء على إمكانيات SCMA في دعم سيناريوهات المستخدمين الزائدين مع تحسين الكفاءة الطيفية وتقليل زمن الاستجابة، مما يشير إلى ملاءمتها لشبكات الاتصالات اللاسلكية المستقبلية مثل الجيل الخامس (5G) وما بعده. [Extracted from the article]
Copyright of Iraqi Journal for Electrical & Electronic Engineering is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
Database: Engineering Source
Description
Abstract:The performance of Sparse Code Multiple Access (SCMA) communication system with Logarithmic Message Passing Algorithm (log-MPA) decoder is introduced. To boost the performance, a Low-Density Parity-Check Code LDPC is used together with Belief Propagation (BP) decoder. LDPC is chosen due to its sparsity property that complements the sparsity nature of SCMA for maximum efficiency and minimum complexity. Three distinct SCMA configurations are used. These are: A (4 x 4 x 6), B (4 x 16 x 6), and C (5 x 4 x 10) where the (K x M x V) are numbers of resources, codewords and users respectively. The performance of these configuration is shown in various channel conditions, various LDPC code rates and various numbers of SCMA iterations (NSCMA), to find the local minimum value of log-MPA. Simulation results showed that the LDPC greatly boosted the performance in mentioned configurations: In A configuration, a gain of 13 dB was observed. Configuration B experienced a substantial improvement of 23.5 dB, while C achieved a gain of 20.5 dB. Notably, configuration B stood out with the highest gain, attributed to LDPC's exceptional performance with high data rates, as the data transmitted in B was double that of A. [ABSTRACT FROM AUTHOR]
ISSN:18145892
DOI:10.37917/ijeee.21.2.23