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.
In this research, performance evaluation of timing synchronization on Orthogonal Frequency Division Multiplexing (OFDM) communication system under Additive White Gaussian Noise (AWGN) communication channel is done. The performance evaluation is done by comparing the existing time synchronization algorithms, here will be presented four types of algorithms to calculate the arrival time of OFDM symbol...
Synchronization technology is another key technology expcet for the equalization in SC-FDE, and it influeces the performance of the communication system in a certain degreee. The paper shows the princeple of SC-FDE and propose a synchronization scheme applied in HF communication based on the analysis of timing synchronization and frenquency offest compensation method. At last shows the simulation...
This paper introduces a new method for adaptively estimating the time-varying autocorrelation (TV-AC) of nonstationary signals and studies its application to time-frequency analysis. The proposed method employs local estimation with a sliding window having a certain bandwidth to estimate the TV-AC locally. The window bandwidths are selected adaptively by a local plug-in rule to address the bias and...
In this paper we investigate different relaying strategies for correlated source transmission in block Rayleigh fading channels. Outage probability close form expressions are derived for both the cases where incremental decode and forward and only simple decode and forward techniques are used in the relays. We show that when using incremental technique in the principal relay, not only we gain in terms...
Mode Group Diversity Multiplexing (MGDM) is an Optical Multiple-Input-Multiple-Output (O-MIMO) technique that provides larger robustness and capacity for data communication over MultiMode Fiber (MMF). The utility of a MGDM system in terms of capacity expansion gives a major interest in most applications of optical communication. In this paper, we propose a transfer matrix decompositioon of O-MIMO...
Since the cardinality of optical orthogonal code (OOC) is small, code length must be increased for the purpose of providing large codeword capacity, which will lead to nonlinearity and reduce the data rate, two-dimensional (2D) wavelength-time (W/T) OOC is more suitable for large capacity system. Aiming at the fact that most of the construction methods of W/T OOC are based on mapping one-dimensional...
CISPR 12 defines the outdoor test site (OTS) as preferred test site and states that an absorber lined shielded enclosure (ALSE) can be used if the results gained there match those obtained on outdoor test sites OTS. The investigation of real sites with a validation method as proposed in [5] is very time consuming. The comparison of real world data with simulation models shall show the feasibility...
The location of foundations in a demolished building can be accomplished by undertaking a Ground Penetrating Radar (GPR) survey and then to use the GPR data to generate 3D isosurfaces of what was beneath the soil surface using image reconstruction. The SIMCA ('SIMulated Correlation Algorithm') algorithm is a technique based on a comparison between the trace that would be returned by an ideal point...
In this paper we propose a joint transmission scheme for LTE-CoMP using a single codeword to transmit from multiple transmission points to a single UE. Transmission with a single codeword makes the signal better aligned with the dominant eigenmode of the channel and achieves higher capacity. A design methodology of the global codebook for joint transmission from two transmission points is developed...
Time-interleaved analog-to-digital converters (TIADCs) are essential in wide-band communication systems for providing high-speed data conversion. However, TIADCs are sensitive to the sample time mismatch, which results in significantly degraded performance. A new calibration technique is proposed to minimize sample time mismatches among interleaved channels. Correlation between adjacent channels based...
A laser 2-focus velocimeter (L2F) has been applied for measurements of velocity and size of droplets in the dense region of diesel fuel spray under the atmospheric pressure condition. The fuel mass distribution in the spray obtained by the measurement was compared with the one simulated by using 3D-CFD code KIVA-3V. The radial velocity of spray droplets near the injector nozzle in the KIVA-3V code...
With rapid development of information and communication technology, human behavior has extended to mobile internet. In this paper, we studied posting behavior of micro-blog users in mobile internet. Statistical results suggest that there exist significant negative correlation between inter-event time and social concern. This means that users' interest in posting micro-blogs is influenced by social...
In this paper, we have studied some important statistical properties of error sequences of M-ary orthogonal frequency-shift keying (FSK) modulation schemes over Nakagami-m fading channels. We have derived the joint probability density function (PDF) of error sequences of arbitrary length. From the joint PDF, we have found an analytical solution for the autocorrelation function (ACF) of the error sequences...
Wireless sensor nodes are battery-powered communication devices. Their limited capabilities have imposed various constraints to the system design of wireless sensor networks (WSNs). These constraints are interrelated, and are usually in conflict with each other. Clustering is often used to reduce energy consumption in WSNs. However, an arbitrary selection of clustering parameters may lead to severe...
An automatic method to discriminate between adiabatic and transient-chirp dominated directly modulated semiconductor lasers (DML), useful to classify telecommunications transmitters, is presented. It is based on calculating the cross-correlation between the optical power and chirp waveforms of the device under test and the use of a decision threshold. The accuracy of the algorithm is demonstrated...
Cognitive radio is proposed to opportunistically access the spectrum while the licensed user is idle. As a result, spectrum sensing procedure to observe primary user's existence is vital to cognitive radio. In this paper, we propose two adaptive sequential cooperative spectrum sensing techniques in time varying channel, namely the Two Stage Sequential Energy Detector and Differential Sequential Energy...
At present, different viewpoints and theories are put forward on divisions and transitions of traffic states in highway, for which decide the fundamental properties of traffic flow. Coherent-moving state, among these states, was firstly proposed in Helbing's paper [1] to discuss the hypothetical steady states in mixed traffic flow in highway traffic. Since then, possible explanations on existence,...
This paper proposes a new method of inter prediction based on low-rank matrix completion. By collection and rearrangement, image regions with high correlations can be used to generate a low-rank or approximately low-rank matrix. We view prediction values as the missing part in an incomplete low-rank matrix, and obtain the prediction by recovering the generated low-rank matrix. Taking advantage of...
An encryption algorithm for high-resolution images based on modified chaos sequence is presented in this paper, which overcomes the restrictions on NCA's (nonlinear chaotic algorithm) effective range. We use the significant digits of samples in chaos sequence to produce the replacement sequence. The simulation results show that the improved algorithm has good real-time characteristic and is suitable...
In this paper, the effect of multiple access (MA) schemes of impulse radio on the power parameters of multiuser interference (MUI) is examined. More specifically, we investigate the ways in which the different MA schemes affect the average power, peak power, and the peak-to-average ratio (PAR) of the matched filtered version of the MUI signal. The results of the analysis performed for a simplified...
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.