scholarly journals Investigation of 2D-WH/TS OCDMA Code Stability in Systems with SOA-Based Device

2020 ◽  
Vol 10 (21) ◽  
pp. 7943
Author(s):  
Mohamed Abuhelala ◽  
Umair A. Korai ◽  
Anderson L. Sanches ◽  
Wing C. Kwong ◽  
Ivan Glesk
Keyword(s):  
Code Division Multiple Access ◽  
Forward Error Correction ◽  
Optical Amplifier ◽  
Photonic Networks ◽  
Probability Of Error ◽  
Multi Wavelength ◽  
Code Division Multiple ◽  
Forward Error ◽  
The Impact ◽  
First Time

This paper investigates for the first time how the implementation of semiconductor optical amplifier (SOA)-based devices in photonic networks can negatively impact the integrity of two-dimensional wavelength-hopping time-spreading (2D-WH/TS) optical code-division multiple access (OCDMA) codes based on multi-wavelength picosecond code carriers. It is demonstrated and confirmed by simulations that the influence of an SOA under driving currents of 50 mA to 250 mA causes a 0.08 to 0.8 nm multi-wavelength picosecond code carriers’ wavelength redshift. The results obtained are then used to calculate the degradation of OCDMA system performance in terms of the probability of error Pe and the decrease in the number of simultaneous users. It is shown that, when the SOA-induced 0.8 nm code carriers redshift becomes equal to the code carries wavelength channel spacing, the (8,53)-OCDMA system performs only as a (7,53)-OCDMA system, and the number of simultaneous users drops from 14 to 10 or 84 to 74 with the forward error correction (FEC) Pe of 10−9, respectively. The impact of the 0.8 nm redshift is then shown on a (4,53)-OCDMA system, where it causes a drop in the number of simultaneous users from 4 to 3 or 37 to 24 with the FEC Pe of 10−9, respectively.

scholarly journals FPGA implementation of trellis decoders for linear block codes

2014 ◽  
Vol 12 ◽  
pp. 61-67
Author(s):  
S. Scholl ◽  
E. Leonardi ◽  
N. Wehn
Keyword(s):  
Forward Error Correction ◽  
Convolutional Codes ◽  
Block Codes ◽  
Point Of View ◽  
Linear Block Codes ◽  
Banyan Network ◽  
Hardware Architectures ◽  
Trellis Decoding ◽  
Forward Error ◽  
First Time

Abstract. Forward error correction based on trellises has been widely adopted for convolutional codes. Because of their efficiency, they have also gained a lot of interest from a theoretic and algorithm point of view for the decoding of block codes. In this paper we present for the first time hardware architectures and implementations for trellis decoding of block codes. A key feature is the use of a sophisticated permutation network, the Banyan network, to implement the time varying structure of the trellis. We have implemented the Viterbi and the max-log-MAP algorithm in different folded versions on a Xilinx Virtex 6 FPGA.

Analysis the flat gain/noise figure using RAMAN-Reflective Semiconductor Hybrid Optical Amplifier in C + L + U triple band for super dense wavelength division multiplexing system

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Chakresh Kumar ◽  
Ghanendra Kumar
Keyword(s):  
Wavelength Division Multiplexing ◽  
Noise Figure ◽  
Optical Amplifier ◽  
Dense Wavelength Division Multiplexing ◽  
Wavelength Division ◽  
Prime Concern ◽  
Flat Gain ◽  
Hybrid Optical Amplifier ◽  
The Impact ◽  
First Time

AbstractNonlinearity, flat gain and noise figure are the prime concern for super dense wavelength division multiplexing (SD-WDM) systems which have been resolved from RAMAN-RSOA hybrid optical amplifier (HOA) for the first time in this paper. Channel capacity is taken up to 400 with data rate of 10 Gbps. Performances are evaluated with respect to C + L + U band for 1520–1680 nm and 1520 to 1640 nm. RSOA is operated at 40–120 mA bias current to attain best rating flat gain of 34.07 dB with variation of 3.5 dB than the others HOAs (RAMAN-EDFA, RAMAN-SOA and EDFA-SOA). Moreover, the impact of EDFA-SOA is not acceptable in terms of noise figure for SD-WDM optical communication system.

scholarly journals Interference in Wireless Networks: Causes, Analyses and Practical Mitigating Techniques

2014 ◽  
Vol 8 (5) ◽  
pp. 56 ◽  
Author(s):  
A. Hameed ◽  
Ali Oudah
Keyword(s):  
Wireless Networks ◽  
Code Division Multiple Access ◽  
Multiple Access ◽  
Interference Mitigation ◽  
Base Station ◽  
Key Characteristics ◽  
Cdma Systems ◽  
Mitigation Techniques ◽  
Code Division Multiple ◽  
The Impact

This paper addresses the key characteristics of interference in wireless networks. Moreover, it considers the impact of interference from Code Division Multiple Access base station to Wideband-Code Division Multiple Access one. A detailed discussion of major interference mitigation techniques in wireless networks, in general, and CDMA and W-CDMA systems, in particular is also imparted on. The techniques and findings in this paper can be easily used in the analyses of other wireless technologies.

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