Aliasing Frequency Detection In a Communication Receiver

Due to cost pressure, device complexity and size issue, most of the digital communication receiver designers try to avoid very sharp Anti- Aliasing filter. And because of that aliasing frequency e.g. image frequency e.g. ghost cell frequency appear inside the digital baseband, which apparently remained un-noticed to the receiver. As receiver is blind about that signal so, it processes the aliasing signal frequency as a desired cell frequency and if the aliasing signal is strong enough, then the initial mobile receiver's operations like, cell search and camp on etc. will be successfully performed using that aliasing signal.

Later, during the uplink transmission time the receiver will discover that it has wrongly camped to an aliasing frequency, as network will not respond to mobile receiver's message due to mismatch in DL and corresponding UL ARFCN.Here in this paper, a simple, fast and efficient method is proposed to detect the presence of aliasing frequency in the received digital baseband signal.

First the dc power at 0 Hz is estimated using I and Q signal average, then that is compared with the dc power after rotating by p radian (e.g. fs/2 '“ half sampling frequency in case of a twice oversampled received signal). If the estimated dc power before rotation is much higher than the dc power after rotations that will indicate there is no aliasing frequency present in the received digital baseband signal. And in such case, the receiver will process further the received signal, otherwise it will discard or take the appropriate action to combat the aliasing.

By Dr. Om Prakash | Dr. Sajal Kumar Das | Dr. N. Rajesha"Aliasing Frequency Detection In a Communication Receiver " Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-1 | Issue-5 , August 2017,

Paper URL: http://www.ijtsrd.com/papers/ijtsrd2279.pdf 

Direct URL: http://www.ijtsrd.com/engineering/electronics-and-communication-engineering/2279/aliasing-frequency-detection-in-a-communication-receiver--/dr-om-prakash

UGC Approved Journal, Engineering Journal

Fe75-xCoxCu1Nb3Si15B6 Alloy with Rapid Stress Annealing

This Articler reports the effect of stress annealing treatment on the structural and magnetic properties of nanocrystalline Fe75-xCoxCu1Nb3Si15B6 & Co21Fe64-xNbxB15 alloys. Information obtained from magnetic measurements, X-ray diffraction measurements and Mössbauer spectroscopy reveal that for Fe75-xCoxCu1Nb3Si15B6 (x = 0, 2, 5) alloys the volume fraction of the Fe-Co nanograins and their grain diameter ranges between 56 to 80 % and 10 to 18 nm respectively.

Annealing treatment at higher temperature also resulted in appearance of Fe3Si nanocrystals along with magnetically hard Fe3B, Fe23B type phases which are responsible for higher coercive field values. Presence of cobalt and applied stress during annealing has considerable effect on relative permeability and stress induced anisotropy, which is and perpendicular to the ribbon axis. Mössbauer spectroscopy analysis also suggests changes in spin texture.

By Shailendra Singh Khinchi"Fe75-xCoxCu1Nb3Si15B6 Alloy with Rapid Stress Annealing" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-1 | Issue-5 , August 2017,

Paper URL: http://www.ijtsrd.com/papers/ijtsrd2272.pdf 

Direct URL: http://www.ijtsrd.com/physics/engineering-physics/2272/fe75-xcoxcu1nb3si15b6-alloy-with-rapid-stress-annealing/shailendra-singh-khinchi

Open Access Journal, Engineering Journal

Stress Annealed CoFeNbB Alloy : A Structural Study

Article presents the influence of Nb content on structural properties of stress annealed Co21Fe64-xNbxB15 (x = 3, 5, 7) alloys has been studied using differential scanning calorimetery, in-situ length change measurements during annealing and x-ray diffraction. Results show that, increase of Nb content in the alloy increases the stability of the alloy against crystallization and is also responsible for higher elongation of the specimens. Crystallization leads to the formation of bcc Fe-Co nano-granular phase containing Co up to 38 % and affects the spin texture.

By Shailendra Singh Khinchi"Stress Annealed CoFeNbB Alloy : A Structural Study"

Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-1 | Issue-5 , August 2017,

Paper URL: http://www.ijtsrd.com/papers/ijtsrd2271.pdf 

Direct URL: http://www.ijtsrd.com/physics/engineering-physics/2271/stress-annealed-cofenbb-alloy--a-structural-study/shailendra-singh-khinchi

Open Access Journal, Engineering Journal

A Reiew on Different Configurations and Control Strategies for PMSG based WECS

The increasing trends in wind energy technology are motivating the researchers to work in this area with the aim towards the optimization of the energy extraction from the wind and the injection of the quality power into the grid. Over the last few years, wind generators based on permanent magnet synchronous generators (PMSGs) are becoming the more popular solution for the modern wind energy conversion systems (WECSs). This paper presents a critical review of the grid-integrated WECSs employing permanent magnet synchronous generators (PMSGs).

It reviews the trends in different configurations, converter topologies, control methodologies, and methods for maximum energy extraction in PMSG based WECSs, which have been reported in various research literatures primarily in reputed research journals and transactions during last few years

By Anita | Satish Kumar"A Reiew on Different Configurations and Control Strategies for PMSG based WECS"

Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-1 | Issue-5 , August 2017,

Paper URL: http://www.ijtsrd.com/papers/ijtsrd2220.pdf 

Direct URL: http://www.ijtsrd.com/engineering/electrical-engineering/2220/a-reiew-on-different-configurations-and-control-strategies-for-pmsg-based-wecs/anita

Paper Publication, Engineering Journal

Interfacing of Grid Connected Wind Energy Conversion System Based on PMSG through NPC Inverter

Wind energy is a prominent area of application of variable-speed generators operating on the constant grid frequency. This paper describes the simulation, operation and control of one of these variable-speed wind generators: the direct driven permanent magnet synchronous generator (PMSG). This generator is connected to the off-grid load. The generator is controlled to obtain maximum power from the incident wind with maximum efficiency under different load conditions. Pitch angle control is designed to extract the power from the wind when speed is more than the base speed.

This paper shows the dynamic performance of the complete system. Different tests in a 8.5-kW prototype have been carried out to verify the benefits of the proposed system.

By Anita | Satish Kumar"Interfacing of Grid Connected Wind Energy Conversion System Based on PMSG through NPC Inverter"

Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-1 | Issue-5 , August 2017,

Paper URL: http://www.ijtsrd.com/papers/ijtsrd2219.pdf 

Direct URL: http://www.ijtsrd.com/engineering/electrical-engineering/2219/interfacing-of-grid-connected-wind-energy-conversion-system-based-on-pmsg-through-npc-inverter/anita

International Journal, Engineering Journal

Control Systems in the Presence of Actuators or Sensors Degradation

In this paper, we design controller that combines an observer and a control to handle systems subject to actuator or sensor degradation (including complete failure). The observer contains a pre-filter, an adaptive law, and a modified Luenberger observer that achieves estimation of system state and estimation of conditions of actuator or sensor. We have shown that if a set of differential Riccati inequatities (DRI) is satisfied then the system can be stabilized under actuator degrad-ation. While in sensor degradation case if an Algebraci Riccati inequality (ARI) and a DRI are satisfied then the system is stabilized.

Chieh-Chuan Feng"Control Systems in the Presence of Actuators or Sensors Degradation"

Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-1 | Issue-5 , August 2017,

Paper URL: http://www.ijtsrd.com/papers/ijtsrd2250.pdf 

Direct URL: http://www.ijtsrd.com/engineering/electrical-engineering/2250/control-systems-in-the-presence-of-actuators-or-sensors-degradation/chieh-chuan-feng

Indexed Journal, Engineering Journal

MIMO Systems with Degraded Actuators and Sensors

This paper presents a reliable control design technique for linear, time-invariant, multi-input multi-output (MIMO) systems with degraded actuators and sensors. The degradation defined in this paper ranges from normal operational conditions to complete failure of actuators and sensors. We derive linear matrix inequality (LMI) conditions ensuring robust stability of the system using static state feedback. The potential of the proposed technique has been demonstrated by an example of three coupled inverted pendulums.

By Chieh-Chuan Feng"MIMO Systems with Degraded Actuators and Sensors"

Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-1 | Issue-5 , August 2017,

Paper URL: http://www.ijtsrd.com/papers/ijtsrd2247.pdf 

Direct URL: http://www.ijtsrd.com/engineering/electrical-engineering/2247/mimo-systems-with-degraded-actuators-and-sensors/chieh-chuan-feng

UGC Approved Journal, Engineering Journal