The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Progress in bio-printing techniques has accentuated the need for non-invasive imaging modalities with high sensitivity, high resolution, and imaging depth of a few millimeters. Mesoscopic Fluorescence Molecular Tomography (MFMT) is a promising imaging modality for 3D localization and quantification of fluorescent labeled cells in thick scaffolds. Here we report on the characterization of our second...
The nonlinear distortion from power amplifier (PA) distorts the signal and causes significant impact on the symbol-error-rate (SER) performance for the electric-power-systems (EPS) communications. This paper proposes a calculation of the optimal input power back-off (IBO) to resist PA nonlinearity, as well as guarantee an appropriate signal-to-noise ratio (SNR), by minimizing the mean square error...
This paper presents a new concept of simultaneous data transfers with existence of multiple harmonic frequency channels. Contradictory to conventional approaches of multiband communication systems, which generate the desired operating frequencies with multiple local oscillators and communicate in time division basis, this proposed harmonic communication system reuse the intermodulation products generated...
In this paper, we propose a Minimum Bit Error Rate (MBER) beamforming combined with Space-Time Block Coding (STBC) according to the number of antenna array. A class of adaptive beamforming algorithm has been proposed based on minimizing the BER cost function directly. Consequently, MBER beamforming is capable of providing significant performance gains in terms of a reduced BER. The beamforming weights...
This paper evaluates the impact of using outdated channel estimates in a multiuser Amplify-and-Forward (AF) relay network, under Nakagami-m fading. Both variable gain AF and fixed gain AF schemes are considered. Expressions for the system's outage probability and the average bit error rate (BER) are derived. Since the expressions are barely tractable, we also present approximations for the high signal-to-noise...
The exact average capacities of rate adaptive single-relay selection decode-and-forward dual-hop relaying for block Rayleigh fading with two cooperation schemes, called parallel channel cooperation and repetition-based cooperation (RC), are obtained. General, dissimilar fading channels and the effect of the source-destination link are considered. Accurate approximations to the average capacity in...
In this study, an enhanced chip-level linear equalizer is proposed for multiple-input multiple-out (MIMO) multi-code code-division multiple access (CDMA) systems in space-time transmit diversity (STTD) mode. By retaining inter-antenna interference (IAI) within the equalized signal in an optimized manner, the signal-to-noise ratio (SNR) of the STTD combiner output is maximized. Substantial performance...
This paper presents the design of low noise CMOS pre-amplifiers. Phone IC is one of the applications that pick-up voice signal from a microphone and the preamp amplifies to audible signal. Normally when the sound signal is very weak the amplifier amplifies signal as well as noise. This may result an amplified sound with low signal to noise ratio (SNR). A simulation study has been conducted to compare...
Time of Flight (TOF) Positron Emission Tomography (PET) produces an improvement in signal-to-noise ratio (SNR) over conventional non-TOF reconstruction. This improvement increases with the size of the patient and with better coincidence time resolution of the system. As a first approximation in TOF PET reconstruction, this gain in SNR is independent of the scatter and random components of the total...
To overcome the problem that the transmission rate of a multicast channel is limited by the user with the worst channel quality, which causes the total system throughput to be low, the use of both multicast and unicast channels for multicast service is considered in this paper. Unicast channels, in addition to a multicast channel, are allocated to users with signal-to-noise ratios (SNRs) lower than...
Elastography is an emerging ultrasonic imaging technique; it has a broad clinical application for tissue parameter estimation. We designed a real-time system to measure tissue stiffness information non-invasively based on transient elastography. The system performance mainly depends on the circuit design before the Analog-to-Digital Converter (A/D), especially the preamplifier part which is very sensitive...
The use of energy harvesting (EH) nodes as cooperative relays is an attractive solution that harnesses the spatial diversity of a multi-relay network and also addresses the vexing problem of a relay's batteries getting drained when it forwards information to the destination. For a general class of stationary and ergodic energy harvesting processes, we analytically characterize the performance of a...
Radio communications possessing high signal quality and long-distance propagation have traditionally been difficult to achieve reliably over shortwave bands (up to 30 MHz). This is due to the analog modulation schemes in use and the vulnerability of shortwave radio to atmospheric disturbances. The development of the Digital Radio Mondiale (DRM) standard in 2001 provided digital coding methods, audio...
It has been shown that quasi orthogonal space time block codes (QOSTBC) can achieve high transmission rate with partial diversity. Constellation rotational QOSTBC can achieve full diversity. In this paper, we present a constellation rotational QOSTBC concatenates Reed-Solomon (RS) error correction code structure. At the receiver, pairwise detection and error correction are first implemented. The decoded...
In this paper, we investigate experimentally the impact of optical amplifiers, namely Erbium Doped Fiber Amplifiers (EDFA) on Optical Burst Switching (OBS) networks, operating at the typical bit rate for current passive optical networks (PON), 2.5 Gb/s. A packet with 216-1 pseudo random binary sequence (PRBS) with an idle length equal to 50000 was studied under different pumping powers of the EDFA...
Antimony based materials have the advantage of having the capability of detecting the mid-infrared wavelength (2 to 5 mum) because of its interesting optoelectronic properties. In this paper we have theoretically studied the noise performance of an In0.10Ga0.90Sb avalanche photodiode to examine its suitability as a detector in optical receiver units. We show that at optimum gain such a device has...
In wireless cooperative networks, the asynchronism between the relays can be a source of diversity which is similar in its essence to the multipath diversity of frequency selective channels. In this context, an asynchronous two-relay two-hop cooperative wireless network using the amplify-and-forward protocol is studied. The outage probability in the high signal to noise ratio (SNR) regime is derived...
In the ultra high-speed sampled ADC system with time-interleaved structure of the software radar, the input signal is sampled non-uniformly because of the sampling-time offset and gain difference of ADC, which product the distortion of the signals, digital spectrum. In this paper, the digital spectrum of the signal sampled non-uniformly is synthetically researched by this ADC with sampling-time offset...
In this paper we investigate the 60 GHz in-car wideband radio channel to assess the feasibility of 60 GHz high bit rate radio communication inside a car. The investigations are based on a measurement campaign comprising different application-oriented transmission scenarios and propagation conditions. We analyze the channel gain, time dispersion and frequency selectivity. Finally, we derive the achievable...
This paper analyzes the performance measures of amplify-and-forward (AF) relaying over non-identical Nakagami-m fading channel. The exact probability density functions (PDFs) of total signal-to-noise ratio (SNR) for variable gain relaying and fixed gain relaying are deduced, and the theoretical formulas of moment generating function (MGF) and moments for fixed gain relaying are presented. Since the...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.