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In this paper, a new linear array configuration inspired by the two-level Nested Array concept has been proposed. The proposed geometry comprises of two Uniform Linear Arrays (ULAs) with different spacings and an additional element, this geometry results in a hole-free Difference Co-Array (DCA). In comparison to most of the existing sparse array configurations, the proposed geometry has simple closed-form expressions for the element positions and Degrees of Freedom (DoFs), also providing consecutive DoFs hence, avoiding the need for spatial interpolation. Spatially Smoothed MUltiple SIgnal Classification (SS-MUSIC) algorithm has been deployed for Direction of Arrival (DOA) estimation. Numerical simulations using MATLAB are performed to exhibit the superior performance of the proposed geometry. Keywords: DOA estimation, Co-array Processing, Spatial Smoothing, Degrees of Freedom, Non-Uniform Linear Arrays

This paper focusses on recovering the degraded pattern in the event of failure of elements in a Smart Antenna System. A well-known optimisation algorithm namely: Levy Harmony Search (LHS) Algorithm is employed to optimise the excitations of the remaining ‘healthy’ elements to recover from the degradation caused due to the element failures. A 1×10 Microstrip Patch Antenna Array, working in the 5G frequency band 3.3-3.7 GHz, is designed to closely observe the effects of element failures, followed by the recovery of the pattern by modifying certain parameters. Algorithm considered is simulated using MATLAB and the results of the simulation are validated using HFSS.

5G or fifth generation of cellular technology, is the successor of 4G LTE. It focusses on high date rate, high system capacity cheaper cost. Although it is still a maturing technology, the countries around the world have already stared implementing of on experimented basis. Massive connectivity is at the core of 5G and thus aim to get different components around us connected to each other. The paper focusses on minkowski loops fractal structures till 2nd iteration making a simpler and cheaper antenna for 5G application of cellular technology. The main feature of this antenna is that it occupied the same space as a regular pattern antenna, but offers a far bigger length for radiation. The resonant frequency taken is 30GHz. The substrate taken is RT-Duriod 6006 with dielectric constant 6.45. The antenna has been designed, simulated and analyzed using the software high frequency structure simulator.

To address the requirements of ever growing demands of data, speed and voice from users, wireless communication plays a great role in the picture. Communication systems are upgraded to 5G networks to meet the demands of data, capacity and QoS, With the help of high speed data rate and a high QoS of signals, State-of-the-art technologies are also taking charge to address the requirements of energy efficiency. Issues related to health and environment are escalating quickly as a collateral in the resolution of higher consumption of resources. In this paper, issues and challenges in designing low energy consuming communication techniques and establishing an efficient network, under the concept of green communication with respect to different parameters of 5G communication have been addressed. With a vision to develop a way to maintain demand and supply equation under green communication concept and a balance in ecological equilibrium, in different aspects the techniques and challenges have been discussed. Key discussions include on statistics of carbon dioxide, the implicit consumption of energy and techniques to mitigate the problems, like D2D Communication, Massive MIMO, HetNets and Green IOT, spectrum sharing, energy harvesting and challenges in achieving them have been discussed. This whole idea falls under the concept and umbrella word of Green Communication.

Performance of a cognitive radio network (CRN) can be degraded by a primary user emulation attack (PUEA). Cognitive Radio (CR) is a potential answer for radio spectrum inefficiency issue. Primary user emulation (PUE) assault is a genuine risk to cognitive radio systems. This problem can be eliminated by disconnecting malicious user from base station after classification process. In this work, K nearest neighbor classifier (KNN) is used to classify the malicious users. KNN is trained by using parameters such data rate, distance, power, frequency of request etc. Also, proposed work is compared with artificial neural network (ANN) which is trained by the same parameters used for KNN training. Security of the network is improved by using Elliptical Curve Cryptography (ECC) as data encryption. Trained classifier can detect the emulating users with high accuracy due to significant parameter selection. To validate the performance, accuracy and sensitivity analysis are carried out, simulation results show that the proposed work performs better in terms of accuracy as compared to that of conventional PUEA classification techniques.

Objectives: This work is introduced to design, implementation and specific analysis of printed miniature uniplanar micro strip low pass filter having a cut off of 15GHz on RT/duroid 6010.2 substrate. Methods/Statistical analysis: Besides, the paper examines simulated responses of three circuits which are predominantly lumped element circuit, stepped impedance and EM simulation with respect to conventional design circuit simulations where in both the design strategy will match the tested results. Findings: This proposed work comprises low pass filter design, lumped design and basic design by using only micro strip lines technology. The EM Structure sight design technique gives good sharp cut-off frequency response when compare with other technique towards low insertion loss which brings about having extraordinary concurrence for incredible relationship. Predominantly, AWR microwave office tool is used for designing and analysis. Application/ Improvements: The proposed design configuration will have more extensive application in advancements like 5G, Satellite, radars, Port Vessel Traffic Services and military communication system.

In this work we are involved in determining the direction of arrival estimation of the signals. For accomplishing this task, we are involved in using genetic algorithm method. Here are many methods of direction of arrival methods, such as MUSIC algorithm, Minimum Norm Method, ESPRIT. Among all the previously existing techniques, MUSIC algorithm is best method of direction arrival estimation method. But the MUSIC algorithm will take more time when compared to the genetic algorithm. If the signal is having more noise conditions, then MUSIC algorithm will not perform well when compared to the genetic algorithm. For 0db SNR, the DOA for the Genetic algorithm is 0.01 % varying but for the same SNR, in the case of MUSIC algorithm, DOS is 5% variation is observed. For a given SNR, the DOA estimated for 4 element antenna array in the case of Genetic algorithm is not observed for the MUSIC algorithm for the same signal SNR and number of antenna elements. Here a comparative study between the Genetic Algorithm and MUSIC algorithm performance is studied. The application can be included in the advanced system where a wireless device can detect the DOA very accurately without doing the more computations. The algorithms are implemented by using the MATLAB tool.

As the technologies leaning towards digitalization, there has been extensive scope for researches in the field of Software Defined Networking. The architectural framework makes the life of network administrators easy by decoupling the data plane and the control plane. This architecture exploits easy configuration of network, thus providing programmable terminal for development of applications related to security, management and logging while the centralized controller gives much more control over entire network. This type of network is at risk due to attacks by the intruders with an intention to slow down or shut down the entire network. One such kind of attacks is DoS attack. DoS attack involves flooding of fake packet flows from a single source into the original packet flow. DDoS is a type of DoS attack where multiple compromised systems, which are often infected with malicious programs, are used to target a single system. Hence to achieve security in distributed environment, it is important to reduce the effect of such attacks. In this paper an approach of mitigating Distributed DoS has been discussed. Approach first detects DDoS using Entropy Detection attack and then uses Bandwidth Prediction method to mitigate it. Entropy is basically used for measuring randomness in the system and there are two essential components to DDoS detection using entropy; window size and threshold.

Antenna arrays have wide range of application in the field of wireless communication. This paper describes the design development and performance evaluation of a novel wideband 1 GHz bandwidth dual linear cross polarization microstrip antenna array operating in 4.9 to 5.9 GHz band. The array consists of corporate corner feeding network with two ports, to realize dual cross polarization for polarization re-configurable applications, such as WiMAX. The antenna array has nine-element dual-polarized array patch elements with a novel corporate feed line network. The proposed array is fabricated and tested with a parasitic stack patch layer. The measured isolation S21 is on an average –30 dB in the required band. The designed antenna has an operating center frequency of 5.4 GHz with 1 GHz bandwidth and array achieves a gain of up to 16 dBi in both the horizontal and vertical ports. The feeding network is basically a 1:3 power divider network and is capable of handling 120 to 150 Watts of peak input-power. The return-loss is better than 12 dB in the required band.

This paper presents the performance analysis of Uniform Linear Array (ULA) and Non Uniform Linear Arrays (NULAs), using Multiple SIgnal Classification (MUSIC) algorithm for Direction-Of-Arrival (DOA) estimation. Non Uniform Linear Arrays are applied to Under Water Communication by constructing a Non Uniform Linear SONAR Array. Another variation of NULA, called the Nested Arrays is compared with ULA in terms of the Degrees of Freedom. The considered Non Uniform Linear SONAR and Nested Arrays are compared in terms of resolution and Array length. MUSIC algorithm is simulated using MATLAB.

This Paper presents the design of interdigital filters for the application of duplexer. The Design is Based on the coupling between the micro strip resonators of Quarter Wavelength Long. The designed filters are of seventh order Chebyshev type with a passband ripple of 0.2dB and FBWs of 6.2% and 5.7%. The structure is simulated in the electromagnetic simulation tool such as ADS. The results achieved are of insertion loss S(2,1) around 2dB, Return Loss S(1,1) is of around 17dB and the stop band attenuation of 30dB. The Alumina substrate with an height of 1.27mm and Dielectric Constant of 9.8 is used to reduce the size of the filters. The Designed filters can be used for the Development of Duplexer by increasing the Stopband attenuation to more than 50dB.

Filters plays important role in the design of RF module for the Communication systems. In this paper we are presenting the microstrip Bandpass filter (BPF) for the Asian Pacific Telecommunication (APT) Band 28. The Filter is of Chebyshev type of 7th order for the frequency range of 758 to 803MHz with a Pass Band ripple and Fraction Bandwidth of 0.1dB and 5.7% respectively. The design is based on the Even and Odd mode coupling nature of the Microstrip Transmission Lines. The Filter is simulated using Advanced Design System(ADS) simulation software. Fr4 substrate with a Dielectric constant of 4.6 with a substrate height of 1.6mm is used. The results obtained shows a insertion loss S(2,1)= −1.7dB and the return loss S(1,1)= −17dB. The designed filter shows good passband response and the good stopband attenuation.

A wideband LNA is design and developed utilizing Hybrid Microwave Integrated Circuit (HMIC) technology for the 1-5GHz bandwidth employing the microstrip line geometric variation. For the performance enhancements in the LNA as for Gain, Noise figure and return loss attributes novel procedures are utilized. The circuit is designed using both lumped elements and distributed components and simulated in AWR microwave office. The LNA design include optimum biasing circuit and microstrip geometric varieties with two distinct renditioned versions. The first version as the geometric structure with radial stubs and second one as linear stubs and whose basic changes were given in the simulation measurements. This paper likewise gives the reasonable strides in insights with respect to hardware implementations. The proposed design especially helpful in the communication systems working under IEEE L and S bands applications. To be more particular it is having more prominent degree application in the radars and defense receiver systems.

The limitations introduced by Mutual coupling have triggered vivid research for its reduction and analysis using different methods. In this paper antennas are arranged such that a particular antenna is affected by the E plane, H plane and E-H plane Mutual coupling with the remaining antennas. The analysed 2×2 antenna structure describes a generalised test case for many practical situations, where individual antenna need to be placed in the close vicinity with other antennas of different orientations for effective on board space utilisation. Rigorous E plane, H plane, E-H plane mutual coupling analysis and interpretations are done for special 2×2 antenna formation. The effectiveness of Rectangular slotted ground structure, Dielectric wall printed with coplanar strip patterns and combinations of both are studied. The paper concludes with a quick note on simulated results. All the simulations are carried out using HFSS tool.

In this paper, a comparative analysis of BER performance of various higher order digital modulation techniques for channel utilization is proposed and the analysis are carried out with SNR as the reference parameter. This performance analysis yields to adaptive modulation technique which can be used to attain high spectral efficiency by modulating the signal at higher order modulation schemes based on channel state information (CSI) from the receiver. Signal over AWGN channel is assumed for the analysis. To achieve lower BER values for a specific SNR, techniques to alter signal characteristics like pulse shaping filters, matching filters and convolution encoding are applied and analysis are carried out. An observation from the above analysis produces lower BER. For 256-QAM at SNR of 20, BER of 4.76×10−3 and grey coded BER of 3.83×10−4 is obtained. Highest possible modulation technique is selected with lower BER obtained. Thus, spectral efficiency which is the prime objective of the proposed paper is achieved. The above results are computed and simulated using MATLAB.

The structure proposed in this paper offers a combined effect of Band stop filtering and creating an additional coupling path for mutual coupling reduction in very closely spaced microstrip patch antennas with edge to edge spacing of 0.03125 λ operating at 2.4GHz frequency. This new structure considerably reduces the mutual coupling from −7.4349dB to −19.01dB without hampering the gain, directivity radiation pattern and return loss of the antenna. An alternative circular strip sandwiched between two horizontal strips printed on both sides of dielectric wall placed between two microstrip patch antennas is proposed. Dielectric wall creates extra coupling path whereas circular strips acts like band stop structure. Optimised patterns and dimensions are after studying different cases and simulating number of trials so as to enhance the isolation between the patches and without hampering the other antenna parameters.

History of wireless technology has witnessed many fabulous ideas. Wireless power transfer (WPT) is one among them. Rectenna is an essential part in WPT circuitry. A step by step approach is followed to develop 4×4 rectangular and 2×2 circular microstrip patch antennas for Rectenna. Simulated 2×2 circular patch antenna arrays at 5.8 GHz consumes large space and unacceptable return loss. The proposed 4×4 rectangular antenna array deigned at 35GHz achieves a gain of 23dB and return loss of −42.4dB at 35.25GHz.

The paper proposes a novel method to analyze the correctness of frequency correction loop in a 2G system, so that the mobile station accurately synchronizes to the base station. The setup contains an automatic frequency control (AFC) module to track and control the frequency/timing offset of the crystal. The main functionality of the AFC module is to estimate the optimum frequency correction value and minimize the frequency error of the system. It also contains a long term learning (LTL) module whose functionality is to derive an estimate for the crystal behavior due to temperature and aging and maintain a learning database containing the frequency correction values for the crystal in the operating temperature range. A separate module is used to correct advance/forward time drift on slave SIM, when oscillator is locked to the Master SIM. Various COST 207 GSM/EDGE channel models for mobile radio communication are implemented to test the frequency correction loop.

This paper presents a methodological approach to analysis and design of UHF BJT feedback oscillators based on linear and non-linear simulations. The BJT oscillator designed using a Radio Frequency (RF) BJT NE685M03 nonlinear device model with the collector grounded to provide the negative resistance and lossy coaxial transmission line with isolated shield terminals in the resonator to set the frequency of oscillation. In particular, it is shown how to find the conditions appropriate for oscillations and performed in a non-linear simulation to predict output frequency, output power, and phase noise of the oscillator from linear simulation. Finally an oscillator is designed and simulated for the frequency of 1.32GHz in the AWR design environment (AWRDE) will be used for the aeronautical radio navigation, amateur radio and military applications.

This paper presents the design and simulation of 2stage low noise amplifier(LNA) for the application of L-band used for mobile satellite communications by using microstrip technology and focusing on development of low noise amplifier operating from 0.6GHz-1.2GHz by using Enhancement Mode Pseudomorphic HEMT ATF34143 from Avago Technologies. The design circuit uses lumped elements to implement with input, output, intermediate matching networks and purpose 2stage is to achieve good gain. Input and output matching network is to produces 50Ω impedance for maximum power transfer. The target simulation are gain (S21) with 30 dB, noise figure (NF) with 1dB throughout the band from 0.6G -1.2GHz, Input Return loss -16dB and Output Return Loss -18dB. A 2stage LNA has successfully designed with 35 dB forward gain, 0.56 dB noise figure, Input Return loss -16dB to -27dB and Output Return Loss -19dB to -23dB by using Advance Wireless Revolution (AWR) Microwave office tool.

This paper proposes a novel building block for designing Narrowband Bandpass Hairpin filter on PTFE laminate using the Radial stubs. The proposed circuit block mainly consists of coupled lines, micro strip lines, and the Radial stubs. The process starts with the theoretical design procedure of the filter. Tuning and Optimization of the design is achieved using AWR Microwave office tool. Finally the result of the optimized design is suitably presented for implementation. Insertion loss (IL) less than 5dB and the Return loss (RL) better than 12dB is achieved with the 11.65GHz center frequency. Electro Magnetic (EM) simulation results show good agreement with the Linear schematic model results.

This paper presents the design and simulation of 2-stage low-noise amplifier (LNA) for the application UHF range used for wireless communications and low-noise amplifier with bandwidth 800 M–1.2 GHz with optimization by using Enhancement Mode Pseudomorphic HEMT ATF34143 from Avago Technologies. The design and simulation uses lumped elements to implement the matching networks and proposed 2-stage is to achieve considerable gain. A 2-stage LNA has successfully designed and simulated with up to 33 dB forward gain, less than 0.58 dB noise figure and with good Voltage standing wave ratio (VSWR) from 1.5 to 1.6 at both input and output side by using advanced wireless revolution (AWR) Microwave office tool.