scholarly journals Simulation of Interference Effects of UWB Pulse Signal to the GPS Receiver

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Xin Huang ◽  
Yazhou Chen ◽  
Yuming Wang
Keyword(s):  
Pulse Repetition Frequency ◽  
Pulse Signal ◽  
Ultra Wideband ◽  
Interference Signal ◽  
Gps Receiver ◽  
Interference Effects ◽  
Potential Threat ◽  
Gps Receivers ◽  
Time Frequency ◽  
Interference Level

Ultra-wideband (UWB) pulse signal has an extremely narrow pulse width and wide frequency bandwidth, which overlaps with the operating frequency band of Global Position System (GPS) receivers, posing a potential threat to their performance. In response to this problem, through mathematical analysis and software simulation, the effects of UWB pulse signal under time-hopping-pulse position modulation (TH-PPM) on the performance of GPS receivers were studied. First, the expression and waveform of the UWB pulse signal were analyzed in the time-frequency domain, and it is concluded that the pulse repetition frequency (PRF) mainly affects the discrete spectrum of the UWB signal and the TH code period mainly affects the continuous spectrum. On this basis, the simulation on the power spectral density (PSD) of GPS signal and UWB signal under different pulse parameters was represented, from which a conclusion can be drawn that the PRF is the main factor impacting the PSD of the GPS signal. Furthermore, this paper analyzed the degradation of GPS receiver equivalent carrier-to-noise ratio (C/N0) and C/A code demodulation bit error rate (BER) under UWB interference, which are the crucial evaluating indicators of GPS signal quality. Eventually, we theoretically calculated the minimum interference level of the UWB interference signal to the GPS receiver, providing a theoretical reference for reducing the interference effects of UWB pulse signal on the performance of GPS receivers.

scholarly journals Wideband-Narrowband Switchable Tapered Slot Antenna for Breast Cancer Diagnosis and Treatment

2021 ◽  
Vol 11 (8) ◽  
pp. 3606
Author(s):  
Seonho Lim ◽  
Young Joong Yoon
Keyword(s):  
Breast Cancer ◽  
Coupling Effect ◽  
Breast Cancer Diagnosis ◽  
Microwave Imaging ◽  
Ultra Wideband ◽  
Slot Antenna ◽  
Pin Diode ◽  
Time Frequency ◽  
Switching Mode ◽  
Meander Line

In this paper, a wideband-narrowband switchable tapered slot antenna (TSA) with a compact meander line resonator for an integrated microwave imaging and hyperthermia system was proposed. A compact meander line resonator, which exhibited band-pass characteristics and provided narrowband characteristics by using one PIN diode, was fabricated beneath the tapered slot of the wideband TSA to minimize the degradation of the wideband characteristics. Moreover, the electromagnetic energy was transferred to the meander line resonator with a coupling effect to ensure effective frequency switching. By adapting a PIN diode on the meander line resonator, frequency switching could be achieved. In this way, the proposed antenna could operate in a real-time frequency switching mode between the ultra-wideband (UWB; 3.1~10 GHz), which is used for microwave imaging, and the 2.45 GHz band (industrial, scientific, and medical, ISM band), which is used for microwave hyperthermia. Frequency and time-domain results proved the applicability of the proposed antenna to an integrated breast cancer detection and treatment system.

scholarly journals Autocorrelation Measurement of Picosecond Pulses with Two-Photon Absorption

2021 ◽  
Vol 2112 (1) ◽  
pp. 012004
Author(s):  
Junbao Chen ◽  
Yitao Yang ◽  
Mingyue Qiu
Keyword(s):  
Wireless Communication ◽  
Response Spectrum ◽  
Pulse Repetition Frequency ◽  
Photon Absorption ◽  
Picosecond Pulses ◽  
Time Frequency ◽  
Two Photon Absorption ◽  
Two Photon ◽  
Electro Optic ◽  
Autocorrelation Measurement

Abstract In this work, an autocorrelation measurement method is proposed to obtain the key information of picosecond pulses using the two-photon absorption (TPA) effect. The autocorrelation measurement process is simulated with a linear tuning of the pulse repetition frequency (PRF). Given the dispersion of picosecond pulses, the profile of the autocorrelation signal is broadened symmetrically. Moreover, the dispersive distribution in time-frequency domain of picosecond pulses and the different bandwidth of the TPA spectrum of materials should bring in sub pulses in the autocorrelation signal with the relative different delay. As shown in simulations, with an ideal broadband two-photon response spectrum, only the broadening of autocorrelation trace appears. But the detection with a narrowband two-photon response spectrum displays the greater sensitivity for pulse dispersion of the edge of the pulse, benefiting from the more sub pulses. Detections of picosecond pulses within the space wireless communication band region generally employ the photoconductive antenna and electro-optic effect in free space. However, with respect to the TPA effect in the specific materials, we could build an extremely compact autocorrelation measurement configuration for the key information extraction of picosecond pulses in space wireless communication and astronomical measurement, which would provide the same information as conventional detections about the autocorrelation signal of picosecond pulses.

Interference of ultra-wideband short electromagnetic pulses of high repetition frequency to GPS receiver

2014 ◽  
Vol 26 (3) ◽  
pp. 33006
Author(s):  
张智香 Zhang Zhixiang ◽  
刘小龙 Liu Xiaolong ◽  
陈锦 Chen Jin ◽  
蒋廷勇 Jiang Tingyong ◽  
曹锐 Cao Rui
Keyword(s):  
Repetition Frequency ◽  
Ultra Wideband ◽  
Gps Receiver ◽  
Electromagnetic Pulses ◽  
High Repetition

scholarly journals Nyquist Zone Index and Chirp Rate Estimation of LFM Signal Intercepted by Nyquist Folding Receiver Based on Random Sample Consensus and Fractional Fourier Transform

Sensors ◽  
2019 ◽  
Vol 19 (6) ◽  
pp. 1477 ◽  
Author(s):  
Xinqun Liu ◽  
Tao Li ◽  
Xiaolei Fan ◽  
Zengping Chen
Keyword(s):  
Fourier Transform ◽  
Random Sample ◽  
Fractional Fourier Transform ◽  
Estimation Method ◽  
Ultra Wideband ◽  
Estimation Methods ◽  
Radar Signal ◽  
Chirp Rate ◽  
Time Frequency ◽  
Random Sample Consensus

The Nyquist folding receiver (NYFR) can achieve a high-probability interception of an ultra-wideband (UWB) signal with fewer devices, while the output of the NYFR is converted into a hybrid modulated signal of the local oscillator (LO) and the received signal, which requires the matching parameter estimation methods. The linear frequency modulation (LFM) signal is a typical low probability of intercept (LPI) radar signal. In this paper, an estimation method of both the Nyquist Zone (NZ) index and the chirp rate for the LFM signal intercepted by NYFR was proposed. First, according to the time-frequency characteristics of the LFM signal, the accurate NZ and the rough chirp rate was estimated based on least squares (LS) and random sample consensus (RANSAC). Then, the information of the LO was removed from the hybrid modulated signal by the known NZ, and the precise chirp rate was obtained by using the fractional Fourier transform (FrFT). Moreover, a fast search method of FrFT optimal order was presented, which could obviously reduce the computational complexity. The simulation demonstrated that the proposed method could precisely estimate the parameters of the hybrid modulated output signal of the NYFR.

scholarly journals Micro-Motion Feature Extraction of a Rotating Target Based on Interrupted Transmitting and Receiving Pulse Signal in an Anechoic Chamber

Electronics ◽  
2019 ◽  
Vol 8 (9) ◽  
pp. 1028
Author(s):  
Feng Zhao ◽  
Xiaobin Liu ◽  
Zhiming Xu ◽  
Yuan Liu ◽  
Xiaofeng Ai
Keyword(s):  
Feature Extraction ◽  
Coupling Effect ◽  
Pulse Repetition Frequency ◽  
Pulse Signal ◽  
Anechoic Chamber ◽  
Repetition Frequency ◽  
Motion Feature ◽  
Whole Process ◽  
Micro Motion ◽  
Rotating Target

The pulse signal is widely used in micro-motion feature extraction of rapidly rotating targets as its pulse repetition frequency (PRF) can be high. However, when the pulse signal is implemented in a range-limited anechoic chamber for micro-motion feature extraction, the transmitted and reflected pulse signals may be coupled at the receiver. To solve this problem, the interrupted transmitting and receiving (ITR) method is applied to transmit the pulse signal with hundreds of sub-pulses. The target echo can be received when the sub-pulse is not transmitted. Hence, it avoids the coupling effect of transmitted signals and echoes. Then, the whole process of micro-motion feature extraction for rotating target is proposed based on the ITR method. At last, the simulations and experiments verify that the rotating target micro-Doppler can be extracted by the ITR pulse signal.

scholarly journals Using Evolutionary Computation on GPS Position Correction

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Jung Yi Lin
Keyword(s):  
Evolutionary Computation ◽  
Global Positioning System ◽  
Handheld Devices ◽  
Correction Function ◽  
Gps Receiver ◽  
Correction Algorithm ◽  
Gps Receivers ◽  
Global Positioning ◽  
Position Correction ◽  
Hardware Reconfiguration

More and more devices are equipped with global positioning system (GPS). However, those handheld devices with consumer-grade GPS receivers usually have low accuracy in positioning. A position correction algorithm is therefore useful in this case. In this paper, we proposed an evolutionary computation based technique to generate a correction function by two GPS receivers and a known reference location. Locating one GPS receiver on the known location and combining its longitude and latitude information and exact poisoning information, the proposed technique is capable of evolving a correction function by such. The proposed technique can be implemented and executed on handheld devices without hardware reconfiguration. Experiments are conducted to demonstrate performance of the proposed technique. Positioning error could be significantly reduced from the order of 10 m to the order of 1 m.

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