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.
When extracting secret key from shared wireless channel between two legitimate moving terminals, its capacity is affected by the time difference of channel sampling, terminal's mobility, and additive noise. In order to quantitatively analyze their effects, a closed-form solution to physical layer secret key capacity in the time domain is derived over the uniform scattering environment. Afterwards,...
When extracting physical layer security secret key with multiple wireless channel samples, its capacity is affected by the time difference of channel sounding, terminal's moving speed, sampling period, the number of samples, and additive noise. In order to quantitatively analyze their effects and determine the constrains on the optimal sampling period, a closed-form solution to the physical layer...
The sidelobe canceller (SLC) is widely used for the array processing to suppress interferences located in the sidelobe of the radiation pattern. In the presence of steering vector mismatch, the performance of SLC may suffer from severe degradation due to desired components cancellation. In this paper, a modified approach is developed to improve the robustness against the direction of arrival (DOA)...
This letter considers the joint acquisition of the carrier frequency offset (CFO) and sampling frequency offset (SFO) in OFDM systems using two long training symbols in the preamble. Conventional maximum-likelihood (ML) methods require a two-dimensional exhaustive search. To overcome this problem, a low-complexity closed-form ML estimator is proposed. It is shown that the CFO can be solved in closed-form...
Interference is a major limiting factor for wireless communications. When interference is independent and identically distributed (i.i.d.), its statistics is invariant with time. The conventional statistical analysis can be used to mitigate the interferences. However, when the interferences are non-i.i.d., few signal processing techniques are available for mitigating the interferences. The matched...
A total rejection of interferences under any noise power is difficult, if not impossible, by current filtering technology. In this presentation, we will show that this is indeed achievable by a new filtering technique that extracts the part of the statistics from the received signals, which depend only on the interferences, not on the signals and noises. The algorithm is blind to the signal and interference...
This paper introduces the use of chaotic Duffing oscillators to ballistocardiograph system for detection of weak signal. A ballistocardiograph (BCG) is an instrument that records the motions of the body imparted to it by the heart beat. It has been found that digital filters are not suitable for processing the BCG signals in noise. So in this paper, we propose a chaotic oscillators algorithm to detect...
A system simulation for a high input-referred second-order intercept point (IIP2) in active mixer of direct-down-conversion (DCR) with adaptive filter calibration is proposed. According to the simulation results of Simulink, by adopting the RLS filter calibration, a DCR mixer working under GSM 900 can achieve an IIP2 enhancement from 53dBm to over 70dBm within 0.3ms. The comparisons between RLS and...
There is rich information of phase in MPSK. Different wavelet coefficient peak collection probability density function and different maximum likelihood function of different MPSK can be obtained from its phase information. These parameters can be used to do modulation recognition for MPSK. In this paper, Morlet wavelet is used to extract the different probability density function and maximum likelihood...
Studies have shown that depending on speaker task and environmental conditions, recognizers are sensitive to noisy stressful environments. The focus of this study is to achieve robust recognition in diverse environmental conditions through extracting robust features. Central to the technique is Root Cepstrum Coefficients (RCC) method, instead of logarithm amplitude spectrum and discrete cosine transform...
A high noisy environment severely contaminates the ECG signal. In this paper, the use of a wavelet transform domain filtering technique as an adaptive de-noising tool, implemented in ECG signal analysis, is presented. The multi-resolution representations of the signal, produced by wavelet transform (WT), are used for signal structure extraction. Experimental results have shown that the implementation...
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.