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Synchronic-in-phase electric drive is widely used in thermal-imaging and laser scanning systems due to high accuracy characteristics in the wide range of angular speed regulation. The point of the article is to examine the application features of impulsive phase-frequency discriminator with extended functional abilities by implementation of different methods of electric drive control with phase synchronization...
An accurate synchronization method for 5G channel measurement is proposed. This method provides stable and accurate (< 1 ns error) synchronized trigger signal to the transmitter and the receiver. Because this method does not need a long cable to provide the synchronized trigger signal, the setup for channel measurement is easy. A verification of a channel in a simple environment is measured. By...
This paper presents a secure image transmission based on a chaotic synchronization. Chaotic systems present unpredictable and complex behavior. These characteristics, together with the dependence on the initial conditions as well as the tolerance of this type of systems, make theme ideal for transmission. In this paper a system of encryption based on chaotic signal is proposed. This system is used...
In order to counteract hostile communication based on the advanced Orthogonal Frequency Division Multiplexing (OFDM) technology, an efficient and unrecognizable jamming technique by failing the OFDM cyclic prefix (CP) functionality is developed in the paper. CP is introduced into OFDM systems to prevent interference caused by the multipath fading, as long as it is no shorter than the channel delay...
A model of input data buffering in measuring systems is developed. The authors obtained the formulae to determine the following time intervals: between two successive transactions to signal source, two successive transactions to signal receiver, between transactions on data receiving and generation, between transactions on data generation and receiving. It is shown that an adequate model of the buffered...
After analyzing the shortcomings of existing synchronization methods based on GPS and the research status of synchronization for Crosswell Electromagnetic Imaging Logging Tool(CEMIT), a feasible synchronization method combined the actual conditions of CEMIT with the basis of existing research is proposed. First of all, GPS receiver provides a high accurate 1PPS, which received by Surface System, and...
A novel run-pause-resume (RPR) debug methodology that can achieve complete cycle-level granularity of debug resolution for multiple clock domain systems is proposed. With this methodology one can pause the normal operation of a system at any cycle of any clock domain and resume the system without causing any data invalidation problem. Bidirectional transactions among different clock domains are analyzed...
We describe a time-of-arrival-(ToA-) based localization system for smartphones. In this system, the transmitter emits modulated light-emitting diode (LED) light and sound waves, then the smartphone catches them. The smartphone measures the time of flight of sound waves and localizes its position using multilateration. The LED light is used for visible light communication, which also conveys the time...
This paper describes waveform design and a multiple access scheme for calibration and pointing correction of a satellite beam-former. These beam-forming functionalities are achieved by a continuous transmission of multiple beacon signals from several, geographically dispersed, calibration earth stations (CESs). As these beacons do not carry any information, their co-channel placement is beneficial...
The problem of secure communication with the multi-antenna transmission in fading channel is an essential task. The fading channel is one of media for the eavesdropper to intercept when transmitting data. We investigate method for security in wireless communication. In particular, we focus on confidential transmission of pseudo-random location of subcarrier to increase security. This security method...
Based on a workshop developed at INICTEL-UNI, this paper presents the methodology and considerations taken to improve the experiences in communication laboratory sessions in Peruvian universities with Software Defined Radio platforms, using a HackRF-One for transmission and a RTL-SDR for reception together with GNUradio Companion, an open source software. The use of these tools allows real communications...
A new time dissemination and synchronization service over public switched telephone network (PSTN) has been established at CSIR-NPL. The time synchronization accuracy achieved using is this service is ± 10 ms. The measurement of round trip delay and its cancellation in the final time code sent to the receiver has been implemented in this service. In this paper, the technical details of this service...
This paper proposes a chaos-based communication scheme which transmits a secret speech signal. To recover the states of the transmitter and the unknown message, the receiver uses a high order sliding mode observer. Its input is one of the states of the transmitter. The control parameters of the observer constitute the secret key of the transmission. The main aspect in which the present work differs...
We study a problem of sequential frame detection over a finite state Markov channel (FSMC). We consider an asynchronous framework where a sync frame of length N symbols is transmitted uniformly over a large interval of known size A slots. In this setup, we study the scaling needed of the sync frame length N with the asynchronism interval length A for error-free frame synchronization. We study the...
We propose a new sensor MAC protocol, called Bird- MAC, which is highly energy efficient in the applications where sensors periodically report monitoring status with a very low rate, as in structural health monitoring and static environmental monitoring. Two key design ideas of Bird-MAC are: (a) no need of early-wake-up of transmitters and (b) taking the right balance between synchronization and coordination...
Molecular communication requires low-complexity symbol detection algorithms to deal with the many sources of uncertainty that are inherent in these channels. This paper proposes two variants of a high-performance asynchronous peak detection algorithm for a receiver that makes independent observations. The first variant has low complexity and measures the largest observation within a sampling interval...
This paper describes the design and implementation of a simple chaotic communication system on FPGA using Rössler's chaotic system of equations. The system was simulated to insure proper operation, before being implemented on hardware using VHDL. Throughput of 2850 Mbps was obtained. The implementation results on Xilinx Zynq-7000 series FPGA show the feasibility of using digital hardware to implement...
In this paper, we present a new amplify and forward (AF) based orthogonal frequency division multiplexing (OFDM) cooperative system with 2 relays. Most of the cooperative systems use distributed space time coding (DSTC) for achieving cooperative diversity, which results in rate-loss. The proposed system achieves full rate and full diversity by utilizing the existing signal space diversity technique...
In this contribution a vectorial channel sounding system for narrowband MISO applications is presented. The channel is measured using a continuous wave signal allowing the characterization of time-variant channels and Doppler shifts within changing multipath propagation environments. The channel sounder's architecture with an analog-digital converter writing the measured data to a SD-card enables...
To increase the attainable data rate of differential chaos shift keying (DCSK), reference-shifted differential chaos shift keying (RS-DCSK) modulation scheme is proposed in this paper. By using both the exact replica and the shifted version of every chaotic reference sample in DCSK as message bearers, two bits of data can be carried in one data-modulated sample sequence., Theoretical analysis and...
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