Optically orthogonal CDMA system performance with optical amplifier and photodetector noise

1999 ◽  
Vol 11 (5) ◽  
pp. 617-619 ◽  
Author(s):  
R.F. Ormondroyd ◽  
M.M. Mustapha
Keyword(s):  
System Performance ◽  
Optical Amplifier ◽  
Cdma System

scholarly journals Comparative Analysis of Erbium Doped Fiber Amplifier (EDFA) and Raman Optical Amplifier (ROA) in Nonlinear-CWDM System

2018 ◽  
Vol 10 (3) ◽  
pp. 144
Author(s):  
Dodi Zulherman ◽  
Sri Utami ◽  
Fahmi Fahmi
Keyword(s):  
Wavelength Division Multiplexing ◽  
System Performance ◽  
Fiber Amplifier ◽  
Optical Amplifier ◽  
High Rate ◽  
Telecommunication Service ◽  
Raman Amplification ◽  
Erbium Doped Fiber Amplifier ◽  
Large Bandwidth ◽  
Erbium Doped

The massive demands for high-rate application drove the telecommunication service to use large bandwidth capacity. The Coarse Wavelength Division Multiplexing (CWDM), a common use in Metro-WDM, can be a solution to provide large bandwidth in optical communications. In a communications system, there are attenuation and nonlinear effect decreasing the system performance. In order to overcome the limitation imposed by electrical regeneration to maintain system performance, a means of optical amplification was sought. In this paper presents the comparison of two competing technologies emerged: Erbium Doped Fiber Amplifier (EDFA) and Raman Optical Amplifier (ROA) to overcome the attenuation in the nonlinear system. We designed the CWDM system using 8 channels with 20 nm channel spacing and 60 km length. The result was conducted by varying the CW Laser power using -8, -6, -4, -2, 0, 2, 4, and 6 dBm. Based on the result of the research, raman amplification can maintain the BER and the Q-factor of the CWDM system better than EDFA. In addition, the received power in raman amplification larger than that received in EDFA. In conclusion,a CWDM system using ROA amplifier has better performance for the system than using EDFA amplifier.

Simulation of CDMA system performance with feedback power control

1991 ◽  
Vol 27 (23) ◽  
pp. 2127 ◽  
Author(s):  
S. Ariyavisitakul ◽  
L.F. Chang
Keyword(s):  
Power Control ◽  
System Performance ◽  
Cdma System

2-Dimensional optical CDMA system performance with parallel interference cancellation

2007 ◽  
Vol 31 (4) ◽  
pp. 215-221 ◽  
Author(s):  
Mikaël Morelle ◽  
Claire Goursaud ◽  
Anne Julien-Vergonjanne ◽  
Christelle Aupetit-Berthelemot ◽  
Jean-Pierre Cances ◽  
...  
Keyword(s):  
System Performance ◽  
Interference Cancellation ◽  
Optical Cdma ◽  
Cdma System ◽  
Parallel Interference Cancellation

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>

scholarly journals Analysis of Multiuser Detectors and Performance improvement in DS-CDMA system using Multistage Multiuser Detection Techniques

2021 ◽  
Author(s):  
Ravindrababu Jaladanki ◽  
Krishnarao Ede ◽  
Raja Rao Yasoda
Keyword(s):  
Computational Complexity ◽  
Multiuser Detection ◽  
System Performance ◽  
Interference Cancellation ◽  
Multiple Access ◽  
Signal Amplitude ◽  
Cdma System ◽  
Parallel Interference Cancellation ◽  
Detection Techniques ◽  
Code Division Multiple

Abstract Among the various interferences, the Multiple Access Interference (MAI) is a significant issue in Direct Sequence Code Division Multiple Access (DS-CDMA) system due to its users. When the number of users is increasing the MAI is likewise increments, subsequently the system performance progressively diminishes particularly in fading environment. In this paper, the system performance is improved by the proposed multistage multiuser detection technique called Multistage Multiuser Differencing Partial Parallel Interference Cancellation (DPPIC). This is the combination of Partial Parallel Interference Cancellation (PPIC) and Differencing Parallel Interference Cancellation (DPIC). Multistage Multiuser Parallel Interference Cancellation (PIC) and Multistage Multiuser PPIC techniques that exist gave improved system performance meaning as the number of stages increases the MAI decreases but at the cost of increased computational complexity. The computational complexity was reduced by utilizing Multistage Difference PIC (DPIC) technique but with no improvement in the performance. To improve the system performance as well as reduce the computational complexity Multistage Multiuser Partial Differencing Parallel Interference Cancellation (PDPIC) method can be used. The simulation results show that the proposed DPPIC technique performs better than PIC, PPIC and PDPIC in terms of Bit Error Rate (BER) versus normalized signal amplitude ( i.e., E b / N 0 ), but computational complexity slightly more than PDPIC in fading environment.

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