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Large computational requirements and high coding-rate appear in primal MPLPC because multi-pulse information in residue signal waveform and glottis pulse's instability have been omitted. To solve these problems, the method of waveform-aided excited-pulse search and number-variable MPLPC is proposed here. First, ascertain the threshold of center clipper used to reduce the search range; then the method...
Since some industrial signals have very low sampling rate, it is impossible to remove the noise from this kind of signal via traditional filter method. This work carefully introduced the wavelet transform de-noise method, including the practical filter bank way to perform the wavelet transform and inverse wavelet transform. The programming work flows of doing signal filtering via wavelet transform...
In this paper, a new approach of blind estimation of subcarrier number based on multiple signal classification (MUSIC) algorithm is proposed for MB-OFDM ultra-wide band (UWB) communications system. The proposed eigenvalue-construct method only using signal autocorrelation of orthogonal frequency-division multiplexing (OFDM) symbols estimates the number of subcarriers. The computer simulations show...
Quasi-Monte Carlo (QMC)-based particle filters can obtain more accurate estimation than the general particle filters, with formidable computational complexity, however. Spatial-domain multiresolutional particle filters are more efficient by reducing the number of particles, but unevenly samples may cause estimation error. Aiming at these, we combine QMC numerical technique and multiresolutional methodology...
Spike detection in neural recordings is the initial step in the creation of brain machine interfaces. The Teager energy operator (TEO) treats a spike as an increase in the `local' energy and detects this increase. The performance of TEO in detecting action potential spikes suffers due to its sensitivity to the frequency of spikes in the presence of noise which is present in microelectrode array (MEA)...
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 a two-way relay network, two terminals exchange information with the help of a relay. Due to its fundamental and practical importance, there has been an increasing interest in this channel. Recently, the notation of bottleneck error exponent has been introduced which is the worst exponent decay between the two links, gives us insight into the fundamental tradeoff between the rate pair and the information-exchange...
In the cross spectral method (CSM), the cross spectral is defined by space-time steering vector. One character of the method is that the cross spectral should be calculated and arranged in every angle-Doppler cell, so it has a great burden of calculation. A new reduced-rand (RR) STAP method is developed in this paper, the cross spectral is defined by the echo data of a range cell, instead of the steering...
In opportunistic relaying, exchanging information is essential to select the best relay. However, too many information-exchanges may rather impair the system performance due to causing congestion in feedback link as well as increasing overhead. In this paper, we investigate the effects of feedback strategies on performances of opportunistic amplify-and-forward (AF) relaying. We consider four feedback...
Cooperative communication usually shares a common model-one source, several relays and one destination. In this paper, we consider the multi-source scenario in a cell to carry on cooperative communication. However, multi-user setting might causes interference in the network, given this interference, the process of relaying selection applies SINR (signal to interference noise ratio) as a criterion...
In this paper, we propose a novel automatic gain control (AGC) algorithm as a solution to improve the signal reception performance based on the IEEE 802.15.4a chirp spread spectrum (CSS) over indoor fading channels. The CSS signals are composed of low-band and high-band signals whose frequency characteristics are different because of multipath fading in indoor environment. It is not appropriate to...
In this paper we consider the spectrum sensing performance and requirements for detecting legacy users (LU) in cognitive radios (CR) with periodic scanning. The performance and requirements are studied based on the temporal spectral occupancy statistics of the LU and the sensing signal to noise ratio levels in order to achieve a certain level of detection probability. We model the temporal statistics...
This paper presents an experimental characterization of the ultra-wide bandwidth (UWB) indoor channel based on an extensive measurement in a PC tower case environment to identify the optimum channel performance. The investigation is based on the analysis of the statistical properties of the multipath profiles, measured over a finely spaced measurement grid. The small-scale statistics of the received...
Aiming at the weaknesses of PS-classifier, it is easily trapped into locally optimal solution and slow convergence velocity when it deals with the complex problems, an improved quantum-behaved particle swarm classifier has been proposed in the paper. Firstly, It introduce the weighted mean best position to improve the performance of QPSO (quantum-behaved particle swarm), and use a novel Michigan rule...
Tangible Acoustic Interfaces (TAIs) are innovative acoustic Human-Machine Interaction devices. Exploiting a number of contact sensors distributed on a surface, the vibrational signal generated from the interaction between the surface and an object moved by the user is acquired and analyzed to recognize what the user is doing on the device. The usage of vibrational sensors naturally opens the way also...
A unique frequency reuse scheme by means of cell sectorization is proposed in this paper that reuses effectively a given frequency resource in a cellular environment. The key concept is to find a scheme that controls interferences among neighboring cells in a systematic manner while achieving high frequency reuse factor. Based on, user distribution in a cell, two problems are investigated. First,...
Ultra wide-band (UWB) communication has to face two problems of multi-access interference (MAI) under multiple access scenario and intersymbol interference (ISI) in multipath environment. In this paper, we proposed a blind adaptive multiuser detection algorithm for direct-sequence code division multiple access (DS-CDMA) UWB systems in ISI channel, called two-stage algorithm, which consists of two...
This paper investigates a spectrum-efficient cooperative diversity method based on butterfly network, which endows that a relay can encode the data received from two users and then forward the coded data to destination. Under the assumption that the relay can reliably overhear the data from two users, we discuss the outage probability and diversity gain. Moreover, the outage probability and diversity...
In cognitive radio systems, secondary users can be coordinated to perform cooperative spectrum sensing to overcome the hidden terminal problem. However, when the number of cooperative users tends to be very large, too many cooperative users will make the whole sensing time intolerantly long and huge consumption of system resource. In this paper, we studied optimal number of secondary users in cooperative...
The rapid growth of diverse wireless communication networks, each with its own unique characteristics, led to proliferation of the wireless heterogeneous network concept. The integration of various networks is not trivial, especially if one targets high performances. Modeling and simulation-based analysis provides sufficient means for performance evaluation, even in the abstract phases of the network...
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