Papers by Abhirup Das Barman
Investigation of inter-channel crosstalk mitigation by assist light in a TOAD switch by using electrical equivalent circuit model of SOA
Optical and Quantum Electronics, Mar 30, 2014
The paper investigates in depth analysis of inter-channel crosstalk in a terahertz optical asymme... more The paper investigates in depth analysis of inter-channel crosstalk in a terahertz optical asymmetric de-multiplexer (TOAD) switch. Large signal multi-wavelength circuit model of semiconductor optical amplifier (SOA) has been developed for crosstalk analysis of the TOAD. The circuit model is particularly suitable for numerical simulation of an integrated TOAD switch in presence of chip and package parasitics. Mitigation of inter-channel crosstalk by continuous wave (cw) assist light is studied experimentally and good prediction accuracy with the numerical result is obtained. It is found that the range of input probe power can be increased by 10 dB when assist light is injected and no error floor is observed. Best performance of crosstalk mitigation is obtained when assist light wavelength is set to the edge of 3 dB bandwidth of the SOA.
Improved Speech Activity Detection Using Cochleagram Spectral Basis by Nonnegative Matrix Factorization
Lecture Notes in Electrical Engineering, 2022
Alamouti Coded Asymmetrically Clipped Optical OFDM for Improved Performance of Multi-Mode Fiber
IET circuits, devices & systems, 2008
An analytical expression for power penalty (PP) from the formula for bit-error rate is derived by... more An analytical expression for power penalty (PP) from the formula for bit-error rate is derived by employing saddle point approximation in the chi-squared probability distribution function. This theory differs from the earlier ones in that it takes into account the dominant signal-amplified spontaneous emission beat noise applicable for optically pre-amplified systems. Imperfect extinction ratio accounting for higher power penalties is also considered in the analysis. Results have been compared with the available experimental results for a low number of crosstalk sources and an excellent agreement has been found. Although Gaussian probability density function (pdf) is simple to analyse, PP calculated from this pdf for a low number of crosstalk sources fails to match with the experimental results.
Electronics Letters, 2018
This Letter proposes a cooperation policy between a macrocell and a hybrid access femtocell in an... more This Letter proposes a cooperation policy between a macrocell and a hybrid access femtocell in an underlay heterogeneous network to improve the achievable data rate of an indoor macrocell user (MU) through time sharing access of the femtocell service together with mitigating cross-tier interference through price-based power control. Through numerical examples it is proved that the authors' proposed cooperation policy is more beneficial to the macrocell not only for providing a higher achievable data rate for its MU but also for earning a higher revenue compared with the incentive-based cooperation policy proposed earlier without much degradation of the achievable data rate performance of any associated femtocell user.
Signal Processing, 2000
The objective of this paper is to critically evaluate the performance of a nonstationary analysis... more The objective of this paper is to critically evaluate the performance of a nonstationary analysis method in tracking speech formant frequencies as they change with time due to the natural variations in the vocal-tract system during speech production. The method of instantaneous frequency estimation is applied to the tracking of speech formant frequencies to observe the time variations in the vocal-tract system characteristics within a pitch period. An implementation of an instantaneous frequency estimator based on the source}"lter model of speech production is described for voiced speech formants. Based on experimental results from simulated as well as natural speech data, it is shown that the accuracy of the frequency estimates is heavily dependent on the nature of the glottal excitation waveform, the fundamental frequency and the frequency spacing of the formants in the speech signal. The choice of various analysis parameters on the accuracy of the estimates is discussed. It is shown that only when the formants are well separated and there are distinct regions of the glottal cycle in which the source excitation can be considered to be negligible, does the instantaneous frequency estimate accurately represent the actual formant frequency. Experimental results on natural speech vowels which show di!erences in formant frequencies in the di!erent phases of the glottal cycle are presented.
Optical Fiber Technology, 2009
This paper reports a unified, accurate and fast simulation tool, able to describe photonic SOA-ba... more This paper reports a unified, accurate and fast simulation tool, able to describe photonic SOA-based digital processing schemes. The model exploits cross gain modulation in SOAs in time resolved analysis in which each amplifier can be thought of as a point amplifier. Simulation and experimental comparisons of the steady state and dynamic amplified spontaneous emission noise behaviour of SOA are carried out. Details of multistage modelling useful for long non-linear SOA has been described. Implementation of schemes such as combinatorial logic functions may require many cascading SOAs and contribution of ASE noise from each amplifier also been taken into account. A procedure of the extraction of parameters from the commercial SOA utilised in the experiment is laid down. Various sources of degradation have been identified and the method for evaluation of bit error rate for complex SOA based combinatorial network has been outlined. The tool is validated through the implementation of a photonic bit comparator. Important design guidelines are extracted by the proposed tool.
Theoretical and experimental investigation of inter-channel crosstalk mitigation by assist light in a TOAD de-multiplexer
Linearity analysis of a frequency tripled optically generated radio frequency signal
2018 3rd International Conference on Microwave and Photonics (ICMAP), 2018
Agilent advanced design systems (ADS) software® is employed to model Mach Zehnder intensity modul... more Agilent advanced design systems (ADS) software® is employed to model Mach Zehnder intensity modulator (MZM) based radio frequency generation at 6 GHz. Linearity analysis of the system is implemented in ADS and verified experimentally. Third order intercept point (IP3) is found within acceptable limit of 51dBm which matches closely with the experimental obtained value.
Index and mode modulated orthogonal frequency division multiplexing with enhanced spectral efficiency
Transactions on Emerging Telecommunications Technologies
IET Communications, 2009
Future interconnection networks will be required to achieve ultra-high bandwidth and low latency ... more Future interconnection networks will be required to achieve ultra-high bandwidth and low latency communications to cope with the increasing performance requirements of backbone routers, large data storage systems and supercomputing systems. Aiming at achieving ultra-high bandwidth communications and approaching optical time-of-flight processing latency while being robust to cascade impairments, the authors propose an all-optical packet-switched interconnection network, where not only the actual packet switching but also the packet processing is performed in the photonic domain. The authors present two modular architectures, based on the crossbar and the Batcher-Banyan topologies, capable of forwarding fixed-length packets with two classes of service. Both use photonic digital-processing subsystems built by combining a single integrable module which exploits cross gain modulation in a semiconductor optical amplifier. System level simulations on the crossbar switch controller guarantee that the control signals maintain an acceptable quality during the processing. Moreover, the Batcher-Banyan configuration is more cost-effective than the crossbar for increasing port count, while effective network performance in terms of packet loss rate can be obtained by adding just few recirculating delay lines.
Multiband radar based on integrated photonics
2021 International Conference on Microwave and Millimeter Wave Technology (ICMMT), 2021
A totally innovative prototype of "software-defined" radar is presented operating on mu... more A totally innovative prototype of "software-defined" radar is presented operating on multiple coherent bands, and made possible by the use of photonics which overcomes the limits of the lack of frequency agility of RF technology. The radar is based on a single photonic transceiver, shared by several radiating units operating in different bands, and implemented on a chip, through the CMOS compatible silicon photonics platform. The data received in the different bands can be used for different functions or integrated through fusion algorithms for a multiband reconstruction of the same scene. This latter approach opens the door to advanced "detection, tracking and imaging" techniques. A prototype of the chip working in the S, C, X and Ku band has been designed built and characterized.
Deep learning technique based real-time audio event detection experiment in a distributed system architecture
Computers and Electrical Engineering
Clustering based voiced-unvoiced-silence detection in speech using temporal and spectral parameters
2015 IEEE International Conference on Research in Computational Intelligence and Communication Networks (ICRCICN), 2015
This paper reports automatic segmentation of voiced, unvoiced and silence portion of speech on TI... more This paper reports automatic segmentation of voiced, unvoiced and silence portion of speech on TIM IT data base. Waveform and frequency domain parameters are used to form multi dimensional feature space. Short time energy threshold of unvoiced segment is used to separate out silence or background from speech. The Gaussian similarity function based spectral clustering is used to find error performance of voiced/unvoiced (V/UV) portion of the speech. The classification accuracy of V/UV is measured and the result is compared with the other techniques available in the literatures. The proposed technique provides at least 98.3% V/UV detection accuracy.
Software Defined Optically Generated Pre-coded QPSK Modulated Microwave Signal
2018 IEEE MTT-S International Microwave and RF Conference (IMaRC), 2018
A phase precoded QPSK modulated frequency tripled microwave signal at 3 GHz is generated opticall... more A phase precoded QPSK modulated frequency tripled microwave signal at 3 GHz is generated optically using an external Mach Zehnder intensity modulator. The modulator can be biased differently to produce double and quadrupled microwave output in a software defined way. Optically generated microwave signal is transmitted wirelessly about 3 m and the received signal is decoded successfully in a software defined receiver. The BER measurement of the received 3 GHz signal demonstrates 2.5 dB power penalty for 30 Mbps data rate at 10−6.
Nonlinear compensation of LEDs for improved performance in CSK based indoor visible light communication
2015 6th International Conference on Computers and Devices for Communication (CODEC), 2015
Performance of IEEE 802.15.7 standard indoor visible light communication employing colour shift k... more Performance of IEEE 802.15.7 standard indoor visible light communication employing colour shift keying (CSK) modulation has been investigated. The paper proposes a technique for non-linear compensation of transmitting LEDs to improve symbol error rate performance of the received CSK constellation of chromaticity points. Performance of field of view (FOV) angle of the LED chip is also increased due to compensation of LED non-linearity which signifies increased coverage area within a room.
Energy-Efficient Frequency Octupling Using Mach–Zehnder Optical Modulator
Computers and Devices for Communication, 2021
SPICE and reservoir models for semiconductor optical amplifiers for high speed optical signal processing
2007 International Workshop on Physics of Semiconductor Devices, 2007
ABSTRACT
Multi-hop D2D Communication in Cellular Networks to Minimize EMR
IEEE Transactions on Green Communications and Networking
On Some Analysis of Optical Microring Resonator to the Generation of Microwave Signal
2018 IEEE Electron Devices Kolkata Conference (EDKCON), 2018
A novel application to the generation of microwave signal has been reported in this paper, where ... more A novel application to the generation of microwave signal has been reported in this paper, where the role of microring is to pass the desired sidebands to the drop, i.e. a notch filter, whereas the architectural modifications has been done to increase the tunability range, with validation of the presented simulation results.
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Papers by Abhirup Das Barman