scholarly journals Convergence and BER Approximation of HIC Detector for DS-CDMA System in Rayleigh Fading Multipath Environment

2020 ◽  
Vol 9 (4) ◽  
pp. 2082-2088
Keyword(s):  
Code Division Multiple Access ◽  
Gaussian Approximation ◽  
Cdma System ◽  
Power Delay Profile ◽  
Rayleigh Channel ◽  
Simulated System ◽  
Multipath Environment ◽  
Code Division Multiple ◽  
Interference Canceller ◽  
Theoretical Results

In this paper we present mathematic analysis and implementation of hybrid interference canceller (HIC) for direct sequence-code division multiple access (DS-CDMA) system in multipath environment over Rayleigh channel. The HIC detector is examined for convergence. The bit error rate (BER) for the system is obtained using Simplified Improved Gaussian Approximation (SIGA). Using this expression, BER is plotted for the Rayleigh channel having exponentially decaying power delay profile (PDP) as well as flat PDP. The theoretical results are compared with the simulated system results.

scholarly journals 2 Performance Evaluation of Code Division Multiple Access (CDMA) in terms of Power Measurement and Reduction

2011 ◽  
Vol 1 (1) ◽  
pp. 4
Author(s):  
Syed Rizwan-ul- Hasan ◽  
Shakil Ahmed
Keyword(s):  
Performance Evaluation ◽  
Code Division Multiple Access ◽  
Multiple Access ◽  
Average Power ◽  
Power Measurement ◽  
Cdma System ◽  
Power Ratio ◽  
Ratio Measurement ◽  
Simulation Results ◽  
Code Division Multiple

 In this research paper the performance of the CDMA system has been analyzed with respect to PAPR (Peak to Average Power Ratio) measurement and its reduction. Simulation results verify that high peaks degrade the performance of CDMA, application of codes reduced high peaks and PAPR is a good measure for CDMA.

scholarly journals The Channel Shortening comparison between OFDM & MC-CDMA System over an ADSL Channel using a Water-filling

2019 ◽  
Vol 9 (5) ◽  
pp. 3695
Author(s):  
Bouasria Fatima
Keyword(s):  
System Performance ◽  
Code Division Multiple Access ◽  
Multiple Access ◽  
Digital Transmission ◽  
Cdma System ◽  
Channel Shortening ◽  
Multiple Paths ◽  
Water Filling ◽  
Cdma Systems ◽  
Code Division Multiple

<p>In this paper our objective focuses on the development of digital transmission techniques in order to solve the problem of Inter-Symbol Interference (ISI) due to multiple paths and the improvement of Multi-Carrier Code Division Multiple Access (MC-CDMA) system performance. The both algorithm: MERRY algorithm (Multicarrier Equalization by Restoration of Redundancy) called TEQ (Time domain EQualizer) and the power allocation method to allocate appropriate power to each user (Water-filling technique (WF)) [1] is used. Finally, the numerical results show that combining Water Filling with TEQ technique allows to reduce the ISI for MC-CDMA systems.</p>

Two Dimensional Tunable Optical-CDMA System

2016 ◽  
Vol 4 (1) ◽  
pp. 125
Author(s):  
Rajesh Yadav Yadav ◽  
Gurjit Kaur Kaur
Keyword(s):  
Prime Number ◽  
Code Division Multiple Access ◽  
Optical Signal ◽  
Optical Cdma ◽  
Cdma System ◽  
Two Dimensional ◽  
Eye Diagram ◽  
Optical Delay ◽  
Code Division Multiple ◽  
Multiple Access System

<p>In this work an experimental demonstration is proposed to implement the synchronous optical code division multiple access system using two dimensional wavelength hopping and time spreading optical prime code is presented. An optical CDMA system is configured on latest version of optisystem by optiwave for the 20 users (Prime Number = 5) connected in a network operating at a bit rate 10 Gbps each. Tunability is achieved by using a MATLAB based delay selector which serves as the source of control signal for optical delay lines. The encoded optical signal of each user has been assigned a particular mode. The resulting optical signal is then transmitted over parabolic index multimode optical fiber. The received signal can successfully be retrieved at the decoder, when the encoder and decoder are configured for the same user. The performance of Optical CDMA system is evaluated in terms of the autocorrelation and cross correlation function, BER, Q factor, eye diagram and compared with 1D code for a given prime number. </p>

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