Optical Interleave-division Multiple-access Research Articles

Long Distance Transmission in Optical-IDMA System

In optical fiber communication system the transmission of signal through optical fiber in long distance with less repeaters can reduce the system’s cost and maintain the signal quality. For long-distance transmission Nonlinear effect and dispersion increases with distance and degrade the signal quality of the optical-interleave Division multiple Access (O-IDMA) system. To reduce Nonlinear effect and dispersion Gaussian pulse has been replaced by Solitons and evaluate the performance. MATLAB has been opted to simulate the Optical fiber channel based IDMA system. Simulation outcomes shows that Solitons may be better option in place of Gaussian pulse for long distance transmission.

Constraint length inflation in fixed high rate convolutional codes and their impact on performance of O-IDMA

<p>To cope up with the higher data rate existing in modern communication systems multiple access technologies has been investigated OIDMA (Optical Interleave Division Multiple Access Technology) is one of the prominent technology use to fulfill this demand. Convolutional codes used in OIDMA systems enhance the performances and reduces the bit error rate of the system. In the present paper, the convolutional codes with increasing number of memory elements are used, the constraint length which depends on number of memory elements are increased with a systematic manner and their combined effect on response of OIDMA system has been observed. Tree inter-leavers in taken into account for analysis purpose and BER with increasing number of users is plotted in graphical and tabular manner.</p>

Impact of code rate and constraint length variation on qualitative performance of OIDMA system with random inter-leaver

The impact of the code rate and constraint length on the qualitative performance of optical interleave division multiple access (OIDMA) system is analyzed. The various topologies of convolution encoder design have implemented by considering various shift registers as well as several Ex-OR gates to achieve the performance. Further, the bit error rate (BER) calculated for a different possible combination of random inter-leaver. The BER increases with the number of users, whereas it decreases with the code rate and constraint length.

High-Speed Detection with Avalanche Photodiode in Optical Interleave Division Multiple Access Scheme

Objective: To execute the Avalanche photodiode instead of a PIN photodiode in Optical Interleave Division multiple Access (O-IDMA) communication system and to analyze the performance for high data rate transmission. Methods/Statistical Analysis: The detection of optical signal at the receiver of the O-IDMA system is an important operation and decides the performance of the system. Here the detection is done using Avalanche Photodiode for O-IDMA system and analyzed. Iterative decoder is used for decoding at the receiver using the soft decision method. MATLAB is utilized as a simulation tool. Findings: The simulation results have been demonstrated that Avalanche Photodiode is appropriate than PIN Photodiode. The completion and efficiency of the O-IDMA system can be ameliorated with the utilization of avalanche photo detector. Applications/Improvements: The completion of the O-IDMA system is ameliorated appreciably by utilizing Avalanche photodiode and system support more no. of users, less bit error rate and large data rate transmission.Keywords: Avalanche Photodiode, Bit Error Rate, IDMA Scheme, Optical Fiber, PIN Photodiode

Fix the Nonlinear Effect and Dispersion in Optical-interleave Division Multiple Access System for Long Distance

Objectives: Nonlinear effect and dispersion are the main factors to degrade the performance of Optical-Interleave Division Multiple Access (O-IDMA) system for long distance. The objective of this paper is to reduce these effects and improve the performance of the system. Methods/Statistical Analysis: Solitons have been utilized as the pulses of transmitting signals in place of Gaussian pulse, to reduce nonlinear effect and recent interleaving mechanisms are applied to decide the optimum in the O-IDMA system. MATLAB is used for simulation. Findings: The simulation results demonstrate that Solitons are the optimum solution for nonlinear effect and Group Velocity Dispersion (GVD) while the prime interleaving mechanism is optimized for user separation in the O-IDMA system. Applications/Improvements: The performance of the O-IDMA system is improved significantly and system support more no. of users and high data rate transmission.

Performance Analysis and Comparison between the Uncoded OIDMA and Convolutional Coded OIDMA

Convolutional coding technique is a low rate coding technique. Optimum multiple channel capacity is achievable only when entire bandwidth is devoted to coding. For maximizing the coding gain the combination of two operations coding and spreading using low rate codes are done. The implementation of convolutional codes in an optical IDMA system provides significant improvement in system performance. Optical interleavedivision multiple-access (OIDMA) scheme inherits the advantage of both Optical system and IDMA technique. For pulse propagation in optical fiber, the nonlinear linear Schrodinger equation (NLSE) is used. OnOff keying (OOK) is used for pulse transmission. It is demonstrated that Convolutional Coded optical IDMA has better bandwidth utilization and less multiple access interference. Convolutional Coded Optical IDMA technique shows that high performance can be maintained with large number of users.

Comparative Study of Random and Tree Base Interleaver for Optical IDMA

Interleave Division Multiple Access (IDMA) is a recently proposed technique for multiple access of wireless communication. In this paper we have IDMA for Optical Fiber medium. In IDMA user specific interleaver are assigned to distinguish the various users. Thus, for good BER, low computational complexity, low bandwidth requirement interleaver should be designed cautiously. Although the performance of optical IDMA can be further improved by using various interleaving schemes. In this work the two interleaving scheme (Random Interleaver and Tree Base Interleaver) is compared in terms of computational complexity and memory requirement to store the interleaving sequences.