Boukerma Sabrina, Belmessaoud Djaouida

Evaluation of ACF, CCF, RAC, RCC and MF Properties of Different Spreading Sequences Used in DS-CDMA Systems

Introduction

Evaluation of acf, ccf, rac, rcc and mf properties of different spreading sequences used in ds-cdma systems. Evaluate ACF, CCF, RAC, RCC, MF properties of spreading sequences in DS-CDMA. Compares Kasami, Orthogonal Gold, and Golay sequences for synchronous CDMA performance.

Abstract

This paper investigates the different sequences that can be used in direct sequence division multiple access (DS- CDMA) systems. The auto-correlation, cross correlation, the mean square correlation measurements ( RAC, RcC ) and merit factor (MF) are used for evaluating the performance of different spreading sequences. The results obtained small set of Kasami sequences is the most effective of binary sequences families in terms of correlation measure, but this set suffers from the limited number of sequences. Overall among orthogonal category, Orthogonal Gold sequences and Golay complementary sequences are a better candidate in synchronous CDMA applications.

Review

This paper undertakes a critical evaluation of various spreading sequences vital for Direct Sequence Code Division Multiple Access (DS-CDMA) systems. The relevance of this study is high, as the choice of spreading sequences profoundly impacts system capacity, interference mitigation, and overall performance. The authors employ a robust set of metrics, including auto-correlation (ACF), cross-correlation (CCF), mean square correlation measurements (RAC, RCC), and the merit factor (MF), to provide a comprehensive assessment of different sequence families. This methodical approach aims to guide the selection of optimal sequences for specific DS-CDMA applications. A significant contribution of this work lies in its comparative analysis, yielding distinct recommendations based on the evaluation metrics. The paper identifies the small set of Kasami sequences as highly effective among binary families due to their superior correlation properties. This is a valuable finding, though the abstract appropriately notes the practical limitation of their restricted number of sequences. Furthermore, the study pinpoints Orthogonal Gold sequences and Golay complementary sequences as strong candidates within the orthogonal category, particularly highlighting their suitability for synchronous CDMA applications. These insights provide concrete guidance for system designers prioritizing correlation performance in specific operational contexts. While the abstract clearly articulates key findings, it also alludes to certain limitations and potential areas for further exploration. The noted constraint of the "limited number of sequences" for Kasami families suggests that practical deployment in large-scale multi-user systems might be challenging. Moreover, the specific endorsement of Orthogonal Gold and Golay sequences for "synchronous CDMA applications" implies that their performance in asynchronous environments, which are common in many real-world scenarios, might warrant further investigation or could be less favorable. Future research could extend this analysis to a wider array of sequence families, explore performance in asynchronous settings, or investigate the trade-offs between correlation properties and implementation complexity. Nevertheless, the paper presents a focused and valuable contribution to the understanding of spreading sequence characteristics in DS-CDMA.

Full Text

Comments

You need to be logged in to post a comment.