scholarly journals Contribution to Synchronization and Tracking Modelisation in a CDMA Receiver

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Aicha Alami Hassani ◽  
Mohcine Zouak ◽  
Mostafa Mrabti
Keyword(s):  
Code Division Multiple Access ◽  
Communication Systems ◽  
Special Focus ◽  
Description Language ◽  
Code Tracking ◽  
Delay Lock Loop ◽  
Orthogonality Conditions ◽  
Hardware Description ◽  
Code Division Multiple ◽  
Cdma Receiver

We propose and analyze a noncoherent receiver with PN code tracking for direct sequence code division multiple access (DS-CDMA) communication systems. We employ the delay-lock loop (DLL) architectures for the tracking stage. The choice of DLL parameters is studied with special focus on DS-CDMA communication systems and orthogonality conditions. We described the modeling and simulation of the NCO using hardware description language VHDL. Details of the VHDL implementation are shown.

scholarly journals Comparison of a Ring On-Chip Network and a Code-Division Multiple-Access On-Chip Network

VLSI Design ◽  
2007 ◽  
Vol 2007 ◽  
pp. 1-14 ◽  
Author(s):  
Xin Wang ◽  
Jari Nurmi
Keyword(s):  
Code Division Multiple Access ◽  
Multiple Access ◽  
Data Transfer ◽  
Performance Estimation ◽  
Description Language ◽  
Advantages And Disadvantages ◽  
Globally Asynchronous Locally Synchronous ◽  
Hardware Description ◽  
On Chip ◽  
Code Division Multiple

Two network-on-chip (NoC) designs are examined and compared in this paper. One design applies a bidirectional ring connection scheme, while the other design applies a code-division multiple-access (CDMA) connection scheme. Both of the designs apply globally asynchronous locally synchronous (GALS) scheme in order to deal with the issue of transferring data in a multiple-clock-domain environment of an on-chip system. The two NoC designs are compared with each other by their network structures, data transfer principles, network node structures, and their asynchronous designs. Both the synchronous and the asynchronous designs of the two on-chip networks are realized using a hardware-description language (HDL) in order to make the entire designs suit the commonly used synchronous design tools and flow. The performance estimation and comparison of the two NoC designs which are based on the HDL realizations are addressed. By comparing the two NoC designs, the advantages and disadvantages of applying direct connection and CDMA connection schemes in an on-chip communication network are discussed.

scholarly journals Constructions of asymptotically optimal codebooks with respect to Welch bound and Levenshtein bound

2021 ◽  
Vol 0 (0) ◽  
pp. 0
Author(s):  
Gang Wang ◽  
Deng-Ming Xu ◽  
Fang-Wei Fu
Keyword(s):  
Code Division Multiple Access ◽  
Communication Systems ◽  
Multiple Access ◽  
Cross Correlation ◽  
Hadamard Matrices ◽  
Circulant Matrices ◽  
Asymptotically Optimal ◽  
Welch Bound ◽  
Construction Methods ◽  
Code Division Multiple

<p style='text-indent:20px;'>Codebooks with small maximum cross-correlation amplitudes are used to distinguish the signals from different users in code division multiple access communication systems. In this paper, several classes of codebooks are introduced, whose maximum cross-correlation amplitudes asymptotically achieve the corresponding Welch bound and Levenshtein bound. Specially, a class of optimal codebooks with respect to the Levenshtein bound is obtained. These classes of codebooks are constructed by selecting certain rows deterministically from circulant matrices, Fourier matrices and Hadamard matrices, respectively. The construction methods and parameters of some codebooks provided in this paper are new.</p>

scholarly journals LARGE-SCALE MIMO MC-CDMA SYSTEM USING COMBINED MULTIPLE BEAMFORMING AND SPATIAL MULTIPLEXING

2018 ◽  
Vol 56 (1) ◽  
pp. 102 ◽  
Author(s):  
Nguyen Huu Trung ◽  
Doan Thanh Binh
Keyword(s):  
System Performance ◽  
Code Division Multiple Access ◽  
Communication Systems ◽  
Multiple Access ◽  
Large Scale ◽  
Spatial Multiplexing ◽  
Propagation Loss ◽  
Fifth Generation ◽  
Simulation Results ◽  
Code Division Multiple

This paper proposes a novel Large-scale (massive) Multi-input Multi-output Multi-carrier Code division multiple access (LS MIMO MC-CDMA) model and application to Fifth-Generation Mobile Communication Systems (5G). This system uses combined cylindrical array antenna multiple beamforming architecture with spatial multiplexing. The model is optimized by Min-Max criteria in order to minimize side lobes and maximize compression of propagation loss. The Monte Carlo simulation results unify with the analytical solution for system performance.

FPGA Implementation of a Novel Construction of Optical Zero-Correlation Zone Codes for OCDMA Systems

2019 ◽  
Vol 0 (0) ◽  
Author(s):  
Samia Driz ◽  
Benattou Fassi ◽  
Mohammed Amine Mansour ◽  
Abdelmalik Taleb-Ahmed
Keyword(s):  
Code Division Multiple Access ◽  
Description Language ◽  
Gate Arrays ◽  
Zero Correlation ◽  
Field Programmable ◽  
Programmable Gate Arrays ◽  
Novel Method ◽  
Zero Correlation Zone ◽  
Code Division Multiple ◽  
Very High

AbstractThis paper proposes a novel method for constructing optical zero-correlation zone (OZCZ) codes based on the Mutually Orthogonal Complementary Sets (MOCS) matrix and the concatenation operation. The most important property of the obtained codes is that the periodic correlation function of the proposed codes is zero for the phase shifts within the zero-correlation zone. The procedure of construction is simple, flexible and offers increasing number of users \left( {M = {2^{n + 1}}} \right). In the other hand, we have presented a fully reconfigurable hardware implementation based on very high description language of the proposed OZCZ codes for optical code-division multiple-access encoder system. The implementation is performed on an Altera field-programmable gate arrays device using ROM memory and an up counter. The simulation results have been found satisfactory and are in conformity with the theoretical observations.

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