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Search Results: 1 - 10 of 4204 matches for " matched filter "
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The Effect of Notch Filter on RFI Suppression  [PDF]
Wenge CHANG, Jianyang LI, Xiangyang LI
Wireless Sensor Network (WSN) , 2009, DOI: 10.4236/wsn.2009.13026
Abstract: Radio Frequency Interference (RFI) suppression is an important technique in the ultra-wideband synthetic aperture radar (UWB SAR). In this paper, we mainly analyze the performance of a notch filter for RFI sup-pression. The theoretical output from notch filter is presented based on RFI signal’s narrowband property. The research conclusion shows that the notch filter has significant effect on sidelobes of the system response, which might be considered to be false targets, however it has little effect on the resolution of the system re-sponse. The theoretical result is verified by simulation and experimental data processing both in one dimen-sion (range dimension) and in two dimensions (range and azimuth dimension).
A Spectrum Sensing Framework for UWB-Cognitive Network  [PDF]
Deah J. Kadhim, Saba Q. Jobbar
Wireless Sensor Network (WSN) , 2010, DOI: 10.4236/wsn.2010.28077
Abstract: Due to that the Ultra Wide Band (UWB) technology has some attractive features like robustness to multipath fading, high data rate, low cost and low power consumption, it is widely use to implement cognitive radio network. Intuitively, one of the most important tasks required for cognitive network is the spectrum sensing. A framework for implementing spectrum sensing for UWB-Cognitive Network will be presented in this paper. Since the information about primary licensed users are known to the cognitive radios then the best spectrum sensing scheme for UWB-cognitive network is the matched filter detection scheme. Simulation results verified and demonstrated the using of matched filter spectrum sensing in cognitive radio network with UWB and proved that the bit error rate for this detection scheme can be considered acceptable.
Design and Comparison of Reconfigurable PerfectlyMatched Bandstop Filters
B. H. Ahmad,M. K. Zahari,Peng Wen Wong
International Journal of Electronics and Computer Science Engineering , 2013,
Abstract: This paper discusses two new designs of reconfigurable perfectly-matched bandstop filter which is based on L-shape and ring resonator. The perfectly-matched bandstop filters can be reconfigured between allpass and bandstop response using PIN diodes as switching elements. The operating center frequency of these filters is at 1 GHz. The discussions of the conceptual perfectly-matched bandstop filters are included in this paper. The filters have been simulated for analysis where the effect of microstrip line and FR4 substrate has been taken into account. It is then further fabricated and measured for verification. The filters will then be compared in terms of s-parameter and size. Result shows good agreement between simulation and measurement.
Joint Closed-Loop Power Control and Adaptive Beamforming for Wireless Networks with Antenna Arrays in a 2D Urban Environment  [PDF]
Mohamad Dosaranian Moghadam, Hamidreza Bakhshi, Gholamreza Dadashzadeh
Wireless Sensor Network (WSN) , 2010, DOI: 10.4236/wsn.2010.211105
Abstract: The interference reduction capability of antenna arrays and the power control algorithms have been considered separately as means to decrease the interference in wireless communication networks. In this paper, we propose smart step closed-loop power control (SSPC) algorithm in wireless networks in a 2D urban environment with constrained least mean squared (CLMS) algorithm. This algorithm is capable of efficiently adapting according to the environment and able to permanently maintain the chosen frequency response in the look direction while minimizing the output power of the array. Also, we present switched-beam (SB) technique for enhancing signal to interference plus noise ratio (SINR) in wireless networks. Also, we study an analytical approach for the evaluation of the impact of power control error (PCE) on wireless networks in a 2D urban environment. The simulation results indicate that the convergence speed of the SSPC algorithm is faster than other algorithms. Also, we observe that significant saving in total transmit power (TTP) are possible with our proposed algorithm. Finally, we discuss three parameters of the PCE, number of antenna elements, and path-loss exponent and their effects on capacity of the system via some computer simulations.
Semiautomatic detection of lanes and bands in DNA gel electrophoresis images  [PDF]
Ashraf K. Helmy, Ghada S. El-Tawel
Journal of Biomedical Science and Engineering (JBiSE) , 2013, DOI: 10.4236/jbise.2013.61010

The following article has been retracted due to the investigation of complaints received against it. The Editorial Board found that the same contents have been published in another journal at the same time. The scientific community takes a very strong view on this matter, and the Journal of Biomedical Science and Engineering treats all unethical behavior such as plagiarism seriously. This paper published in Vol.6 No.1 76-84, 2013 has been removed from this site.

Title: Semiautomatic detection of lanes and bands in DNA gel electrophoresis images

Authors: Ashraf K. Helmy, Ghada S. El-Tawel

Experimental Confirmation of the Doubts about Authenticity of Event GW150914  [PDF]
Alexander V. Lukanenkov
Journal of Applied Mathematics and Physics (JAMP) , 2017, DOI: 10.4236/jamp.2017.52046
Abstract: It was produced processing of the LIGO 14.09.2015 registration data. It was established that the chirp signals (signals of merger of black holes) are absent in the data. This is proved by using a coherent filtering and also two-stage causal filtering. Soliton-like signals such as wavelet “Mexican hat” are found by filtering based on the Butterworth filter. These signals are different in polarity, and their spectra are quite different. Doubts about the authenticity of the detection of chirp signals, which announced on February 11, 2016, are justified by the results the conducted analysis.
Matched Filter Based Spectrum Sensing on Cognitive Radio for OFDM WLANs
International Journal of Engineering and Technology , 2013,
Abstract: For the unlicensed users to use the licensed spectrum, unused frequency bands called white spaces need to be detected. Cognitive radio does this task by dynamic spectrum access. This requires intelligent spectrum sensing techniques. In this paper such unused spectrum for OFDM WLAN (IEEE 802.11a) is predicted by exploring the signals presence in minimum time using matched filter based detection incorporating optimal threshold selection, thereby increasing the sensing accuracy andinterference reduction of secondary network.
International Journal of Engineering Science and Technology , 2011,
Abstract: In modern times, radar is used in a wide variety of applications including defense, air traffic control, meteorology, and even mapping. Radio Detection and Ranging (RADAR) involves the nterpretation of a signal to determine characteristics of targets. With the unavoidable presence of various types of interference, signalprocessing is naturally an important part of any radar system. In this paper, we used a series of 8 bit costas sequence [2], each pulse having a length of 5 microseconds. The interpulse period was 200 microseconds and the radar return receive window started 20 icroseconds after pulse transmission and ended 170 microseconds later. The radar system sampling rate and carrier frequency were 10MHz (2x over sampling) and 5GHz respectively. The noise was Gaussian and had a standard deviation of 2 relative to the signal amplitude. With these parameters detectable targets lay in between 3.7 km to 29.0 km away, and moved with a speed under 53 m/s.
Synthetic Aperture Radar - Hardware Development
V. Rosner,R. Seller,L. Dudas,K. Kazi
Radioengineering , 2009,
Abstract: Experimental real and synthetic aperture radar are developed from the base-band digital unit to the analogue RF parts, based on solid state units, using pulse compression for radar imaging. Proper QPSK code is found for matched filter.
Design and Analysis of an Efficient Primary Synchronization Signal Detector
American Journal of Engineering Research , 2013,
Abstract: In this paper, we present a novel design for the detection of primary synchronization signal in a Long Term Evolution (LTE) system based device at the expense of low cost and low power. This is facilitated by using a matched filter architecture which incorporates parallel processing. The approach of a 1-bit analog-todigital converter (ADC) with down-sampling is compared with that of a 10-bit ADC without down-sampling under multi-path fading conditions defined in LTE standard for user equipment (UE) performance test. A high performance primary synchronization signal detection method is derived in this paper.
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