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Currently the multichannel readout chip for GEM detectors with an asynchronous architecture is being developed. The readout channel includes a preamplifier with fast and slow CR-RC shapers, discriminator with a differential threshold setup circuit, a 6 bit SAR ADC (40 Msps rate, 1.5 mW power consumption), digital peak detector and block of the time stamp registration. The digital peak detector has...
The military wireless systems often have specific constraints such as achieving very good receiver sensitivity, very high tolerance to frequency shifts and best possible dynamic range. Direct spread spectrum (DSS) is the proven threat free technology in many militarized wireless systems, which will also gives the advantage of good receiver sensitivity because of spreading gain it offers. The RF dynamic...
A cost effective approach for better communication to overcome the near-far problem in CDMA system in case of Direct Sequence Spread Spectrum (DSSS) multiuser system instead of single user is depicted in the paper. The need for improvement of the hearability problem in modern telecommunication system has huge applications in security section. A comparative study of Bit Error Rate (BER) vs Signal to...
For evaluating the electromagnetic emission (EME) of an integrated circuit (IC) during the design phase, a precise transient simulation of the disturbing signal is required. This usually takes a lot of time, so that simulating a signal trace longer than a couple of ms is not feasible. In this paper an extension to an existing electromagnetic interference (EMI) receiver model is introduced, which enables...
We report a demonstration of narrow-beam laser communication through the waters of Narragansett Bay in Rhode Island, USA. The transmitter and receiver were mounted on an aluminum truss and placed in the water alongside a pier operated by the Naval Undersea Warfare Center. The transmitter consisted of a real-time modulator and encoder, a 515 nm wavelength commercial laser, collimating optics, and a...
This paper considers the detector design and performance analysis in a widely separated multiple input — multiple output (S-MIMO) radar. We studied this subject under some assumptions such as single point target, Swerling models for radar cross section and Gaussian interference. The target is moving in piecewise linear trajectory and multi-scan data is stored. So, the target cell maybe changed through...
In this paper we consider the problem of designing LDPC codes to be used in bit turbo-receivers, where an outer binary (turbo) decoder iterates with a bit-detector computing LLR of coded bits from the channel outputs. This receiver structure has been proposed for several scenarios, including systems for high order modulations, MIMO, ISI, and Multi User systems. It has been shown that the bit turbo-receiver...
We investigate the problem of increasing the spectral efficiency of current high rate telemetry systems in two different scenarios, which exploit one and two channels, respectively. We will analyze several techniques aimed at improving different stages of the transceiver scheme. We will optimize the transmission parameters and apply advanced receiver architectures, able to take into account part of...
Cognitive Radio (CR) Technology has emerged for the future of wireless communications, its key parameters of interest are frequency, power and modulation techniques. The Spectrum Sensing is an important task to determine the availability of the vacant channels. In Multicarrier Communication using Digital Signal Processing Techniques, Filter Bank Multi Carrier (FBMC) has an edge over other technologies...
With the introduction of Fast Fourier Transform (FFT) EMI receivers, the time required to perform electromagnetic interference (EMI) measurements has been drastically reduced. In theory, these instruments allow measuring the whole band at once. However, aspects related to (i) the level and band of input interference, (ii) prescriptions in EMI normative (i.e., CISPR 16-1-1), and (iii) achievable performance...
Cognitive radar is a new paradigm to conceive the next radar generation characterized by unique and amazing features inspired to mental abilities and processes related to knowledge. It goes beyond the usual extraction of information from the measurements and requires the radar to get intelligence. Introduced by Haykin [1] and Guerci [2], it is attracting huge attention within the radar community during...
In this paper, an optimized codebook design based on rotated angles and extrinsic information transfer (EXIT) chart for a non-orthogonal multiple access scheme, called irregular sparse code multiple access (IrSCMA), is presented. Unlike regular SCMA, in IrSCMA, the defined degree of layer's resource nodes is different, which is beneficial to system performance.It is demonstrated that the new codebook...
The mean bit error rate (BER) for the uplink of a multicarrier-code-division multiple access (MC- CDMA) cellular system is evaluated. The system employs a multiuser decorrelating detector in the receiver, a uniform antenna array at base stations and perfect power control. The scenario assumes the presence of multiple access interference (MAI), co-channel interference (CCI), additive white Gaussian...
In this paper, the impact of the malicious users and the Primary User (PU) traffic in a Cognitive Radio (CR) network considering the existence of Primary User Emulation Attack (PUEA) are studied. Intelligent attackers are considered which they do not make the channel busy all the times. We consider a traffic model for PUEA and PU simultaneously. Then, an effective fast scheme is proposed to identify...
The integrity of messages in vehicular ad-hoc networks has been extensively studied by the research community, resulting in the IEEE~1609.2 standard, which provides typical integrity guarantees. However, the correctness of message contents is still one of the main challenges of applying dependable and secure vehicular ad-hoc networks. One important use case is the validity of position information...
We propose an improved scheme of hybrid quantum key distribution based on the combination of differential phase shift and BB84 polarization encoding. By adjusting the polarization properly and routing all the probability amplitudes to interfere, a higher protocol efficiency of 3/2 is obtained. A better stability can be achieved with the birefringence effects and polarization-dependent losses at the...
We present and evaluate a multiple-input multiple-output visible light communications (MIMO-VLC) system using imaging angle diversity receiver (ImADR). Differing from the conventional imaging receiver (ImR), which has a two-dimensional circular detector array consisting of vertically oriented detectors, the ImADR has a three-dimensional spherical-cap-shaped detector array composed of angle diversity...
In this paper, we consider a confidential communication through multi-cellular co-located multiple-input multiple-output (C-MIMO) and distributed MIMO (D-MIMO) networks in the presence of an eavesdropper. The base station (BS) of each cell sends a common stream of information to a group of receivers within the cell and an eavesdropper observes their communications. We are interested to protect these...
In a number of scenarios, detecting the presence or absence of a known signal may be of practical interest. One such example lies in a communication setting, where packet detection is a vital first step to decode transmitted data. The detection problem can be formulated as a binary hypothesis test within the Neyman-Pearson (NP) framework. Our scenario of interest is warm shallow waters, where the...
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