Time-Frequency and Detection of Abrubt Changes Techniques Applied to Perception and Recognition by Zigbee Wireless Communication

2018 ◽  
Author(s):  
Smain Femmam ◽  
Lyes Bait
Keyword(s):  
Wireless Communication ◽  
Time Frequency

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.

scholarly journals The Development of FPGA-based Wireless Channel Simulator using LabVIEW

2013 ◽  
Vol 64 (3) ◽  
Author(s):  
Nor Aswani Mamat ◽  
Razali Ngah ◽  
Uche A.K Chude Okonkwo ◽  
Muhamad Asmi Ramli
Keyword(s):  
Wireless Communication ◽  
Doppler Shift ◽  
Channel Model ◽  
Wireless Channel ◽  
Communication Link ◽  
Good Communication ◽  
Time Frequency ◽  
Channel Simulation ◽  
Increasing Demand ◽  
Channel Simulator

The development of channel model for wireless communication system is currently becoming important to fulfill the entire user’s requirements and increasing demand where to provide a good communication link between the users at everywhere and anytime. An accurate techniques or operator is needed to model a very flexible channel for wireless communication application. Previous channel model is developed based on the time-frequency operator which is limited to Narrowband signaling. This operator uses Doppler shift to account for mobility in propagation space. This paper proposes a Wideband channel model which is valid for all kind of signaling and conditions. Mathematical channel model is used to represent a generic channel simulator which is implemented as channel simulator. The development and measurement of channel simulator is using LabVIEW. The LabVIEW can be used as basic software and can be turned into hardware part by connecting to other devices for real-time channel simulation. The illustration and snapshot of the channel simulator modeling in term of LabVIEW code program are presented.

scholarly journals Analysis of WOFDM over LTE 1.25 MHz Band

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Sandeep Sarowa ◽  
Naresh Kumar ◽  
Ram Sewak Singh
Keyword(s):  
Wireless Communication ◽  
Orthogonal Frequency Division Multiplexing ◽  
High Speed ◽  
Discrete Wavelet ◽  
Bandwidth Utilization ◽  
Error Performance ◽  
Time Frequency ◽  
The One ◽  
Achievable Data Rate

Orthogonal Frequency Division Multiplexing (OFDM) is the one of the most preferred multiplexing technique for realizing high-speed wireless communication, like Long Term Evolution (LTE) and LTE-Adv. In the era of digital wireless communication, applications of wavelet theory have been favorably applied in many areas of signal processing. Orthogonality, flexible time-frequency analysis, and the ability to characterize signals accurately have attracted the attention of the telecommunication community to use wavelet as a basis function for OFDM. In this paper, discrete wavelet transform (DWT) has been proposed as an alternative signal analysis with multiple merits such as support high-speed applications, immune to distortion, wavelet diversity, better error performance, and efficient bandwidth utilization. A simulative analysis of various wavelets, at different modulation techniques, over OFDM has been presented to demonstrate the improvement in BER performance. Further, in accordance with the LTE parameterization over 1.25 MHz band, the performance of wavelet-based OFDM (WOFDM) is found significantly higher in terms of maximum achievable data rate and system spectral efficiency.

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