Showing papers by "Simranjit Singh published in 2018"

Review on developments in all-optical spectral amplitude coding techniques

Abstract: The focus of this work is to consolidate a review of accomplished research in the field of optical code division multiple accesses (OCDMA), to outline the state-of-the-art comparison, and to recognize the prominent trends as well as limitations. Code division multiple access (CDMA) has prospered as a vital solution for numerous applications such as cellular mobile communication-based wireless network technology and wired/wireless local area networks that include areas of unlicensed industry, medicine, and science. Due to the commercial utilization of the various advantages of CDMA, it has raised the matter of whether optical technology reliant communications provide the noteworthy advantages to optical networks as well as what are the technologies that facilitate optical chip-based (code division) networks. Aforementioned matter has been addressed in the context of the incorporation of OCDMA in the systems through several experiments of laboratory-based test-bed investigations, field trials, and simulation analysis of multiple users in the recent research works. The performance of OCDMA has an edge over wavelength division multiplexing and offers an unmatched capacity that is seen through simulations. To cater the explosive expansions in internet application, different spectral amplitude codes have been proposed till now. We present a review of the different spectral amplitude codes based on the reported works in spectral amplitude code OCDMA systems. For the purpose of state-of-the-art comparison, parameters considered are data speeds, advanced modulation formats, bit error rate, extinction ratio, decision algorithms, photonic efficiencies of photodetectors, frequency bands, signal-to-noise ratio, forward error correction, photodetector noises, etc., and simulations are carried out in similar input environments. We explore the advantages/limitations of the spectral amplitude codes, recent progress in the technology, practical works on spectral amplitude coding (SAC) throughout the world, encryption–decryption techniques, all-optical methods, literature comparison, future scope, and applications of the SAC-OCDMA codes.

Analysis of Average Symbol Error Probability of MDPSK, MFSK and MPSK in the Beaulieu-Xie Fading

Abstract: In this paper, closed-form expressions for average symbol error probability (ASEP) of M-ary differential phase-shift keying (MDPSK), non-coherent M-ary frequency-shift keying (MFSK), and coherent M-ary phase-shift keying (MPSK) over the Beaulieu-Xie fading channel are derived. The Beaulieu-Xie fading channel was proposed by Beaulieu and Jiandong to analyze the conditions of wireless environments in which the received power consists of multiple-specular components with some diffuse power e.g. high speed trains and femtocells. In this paper, no approximation has been used to derive the ASEP. The results demonstrated in this paper are supposed to give important and useful information to evaluate the performance of fading channels. The verification of analytical results is done by comparing them with Monte Carlo simulations.

A Novel Zero Cross-correlation Diagonal Identity Matrix Code

Abstract: Optical Code Division Multiple Access system (OCDMA) is an imminent technology to expunge the limitations of ever increasing data traffic and multiple user access in optical networks. However Multiple Access Interference (MAI) and cross correlation among different codes are prominent issues of SAC OCDMA systems. In order to eliminate cross correlation and to suppress MAI, in this work, we proposed novel Zero cross-correlation (ZCC) Diagonal Identity Matrices codes (DIM). Further, comparison of DIM code is carried out with Enhanced Double weight Codes (EDW) in similar environment in terms of Bit error rate, extinction ratio, Q factor, signal to noise ratio, eye height etc. Codes are investigated at the speed on 30 Gbps and total simultaneous users considered are seven. Mapping free technique is used for both OCDMA SAC-codes which permits service provider to design codes for large no. of users. Proposed novel SAC-OCDMA diagonal identity matrix codes have advantage that it can be designed for any number of users. It is perceived that due to zero cross correlation DIM codes exhibits better performance than EDW codes.

A Novel Two-Dimensional Material Based Optical Fiber Surface Plasmon Resonance Sensor for Sensing of Organic Compounds in Infrared Spectrum Window

Abstract: Glucose, sucrose and fructose are typical organic compounds having carbon-hydrogen-oxygen atoms. Their sensing is important in many bio-medical applications. In this paper we present a 2D material-based fiber optic surface plasmon resonance sensor for refractive index sensing of some typical organic compounds. 2D material graphene in combination with active metal gold is used in the sensing region. Fiber core is covered with gold and graphene layer. The sensor is simulated using COMSOL Multiphysics simulation software. To measure the sensing performance of sensor we see the effect of two physical parameters of the sensor, thickness of the Au-metal and graphene layer on the sensing performance. The use of graphene layer enhances the sensitivity of SPR sensor. The angular interrogation method of SPR excitation is used for sensor simulation in COMSOL Multiphysics.

Multiband Reconfigurable Patch Antenna for Millimeter Wave Applications

Abstract: The main objective of this research work is to design a multiband reconfigurable patch antenna for millimeter wave applications. In this paper, a slotted circular patch antenna is designed on Polymide substrate material with dielectric constant 3.5. To reconfigure patch antenna, two MEMS switches are placed within slots inside the patch and are investigated under four different conditions by alternatively turning ON/OFF MEMS switches. The different performance parameters such as return loss, gain and Voltage Standing Wave Ratio (VSWR) are measured and it is found that the proposed antenna is efficiently resonating on three frequency bands by tuning the switches with effective gain and VSWR. The proposed reconfigurable antenna is resonating on important frequencies such as 30GHz, 35GHz, 45GHz and 60GHz with effective gain and VSWR without changing the dimension of patch antenna. This antenna can be used for millimeter waves based high speed short range wireless communications, sensing and security applications.

Performance Investigation of 1.68 Tb/s Spectral Efficient Hybrid OTDM–WDM System Using Orthogonal Modulation Format

Abstract: In this paper, the performance of return-to-zero/differential quadrature phase shift keying/polarization shift keying (RZ/DQPSK/PolSK) orthogonal modulation format is investigated in hybrid optical time division and wavelength division multiplexing (OTDM–WDM) technique to increase the spectral efficiency of the system. The error free performance is achieved over 140 km transmission with the acceptable bit error rate (~ 10−12). The original contribution of this paper is to propose a bandwidth efficient OTDM–WDM system that could be projected even in high speed scenario and expected to be more technical viable due to use of optical orthogonal modulation formats.

A Time and Wavelength Division Multiplexing based Next Generation Passive Optical Networks Provisioning 80Gbps Symmetrical Access Rate

Abstract: In this paper, a symmetric 80Gbps next generation passive optical network (NG-PON) architecture has been presented. To achieve 80Gbps symmetric data rate, eight pairs of wavelengths have been used. Wavelength division multiplexing (WDM) technique is used at the central office (CO) to transmit downstream data. For downstream access, each wavelength is divided into eight parts by 1×8 splitter and the system supports 64 ONUs (Optical network units). All the 64 ONUs transmits their upstream data by sharing eight upstream wavelengths using time wavelength division multiplexing (TWDM). The performance of the system has been assessed in terms of minimum bit error rate (BER) and Q-factor for the varied distance from 10 km to 100 km. From the results, it has been observed that the presented system works well up to 65 km system length.

Performance Analysis of Non-coherent Modulations over FTR Fading Model

Abstract: In this research paper, an exact error performance analysis for non-coherent modulation schemes over fluctuating two ray fading model (FTR) has been analyzed. Non-coherent modulation schemes can be the preferable mean to analyze the error probability in a practical scenario. Here the focus is done also on the comparative analysis of various non-coherent modulation techniques for FTR model. This model has been considered as a generalization of two wave diffused power (TWDP) fading model in which two specular components are considered to be fluctuating because of variation in amplitude and random phases along with other diffuse components instead of constant amplitudes. This model effectively deals with the problem of spectrum shortage because of its accurate measurements at millimetre (mm) scale of the wave spectrum. In this paper, system performance is studied by calculating average bit error rate (ABER) over FTR fading model by observing variation in various parameters such as K, m and $\Delta $. The derived results are compared with the results of special cases calculated in the literature.

Exact BER for MDPSK and MPSK over Generalized Rician Fading Channel

Abstract: Generalized Rician fading (GR) channel model is the parent model of existing fading models which are special cases of this fading channel. The exact performance evaluation for different types of modulation schemes over generalized fading channel is of great interest and importance. In this paper, exact error probability results for M-ary differential phase shift keying (MDPSK) and M-ary phase shift keying (MPSK) over the GR fading channel are derived. This fading channel provides improved average symbol error probability (ASEP) when compared with other fading channels. The obtained analytical results provide the performance evaluation of the given fading channel. The accuracy of analytical results is justified magnificently by MATLAB simulations.

Blocking Probability Reduction in Optical Networks to enhance the Quality of Service

Abstract: The blocking probability is studied for improving the quality of service of the network. The call blocking model for mode of operation to determine the types of applications suitable for optical switching networks is proposed. A mathematical model of the optical network for blocking probability of cleared calls and holding calls is developed. In the proposed model, blocking probability of the network is reduced as number of servers increases with different number of wavelengths. The proposed models improve the blocking performance of the network and decrease the blocking probability of the network to a level of $\pmb{10^{-28}}$ .