Ultrawideband Chaotic Radio Pulses Research Articles

Моделирование энергетического приемника для систем сверхширокополосной хаотической радиосвязи

The problem of modeling an energy receiver of ultra-wideband chaotic radio pulses for chaotic radio communications is studied. As is shown, a combination of numerical and analytical modeling completes the problem of calculating characteristics of ultra-wideband chaotic communication systems. On the one hand, the numerical method is effective for calculating receiving systems with short radio pulses, and with an increase in the duration of radio pulses Tp the rate of the method decreases proportionally, whereas technical requirements for the computing equipment increase proportionally, so the operation time increases faster than Tp. On the other hand, the accuracy of the analytical solution, which is insufficient in the case of short radio pulses, grows proportion-ally with an increase in the duration of the radio pulses. Thus, in this problem, the numerical and analytical methods ideally complement each other. It is shown that the accuracy of the approximate analytical solution for the optimal threshold and the error probability becomes sufficient for engineering calculations at the values of the number of freedom degrees (processing gain) of chaotic radio pulses B  200. The combination of numerical and analytical modeling methods can significantly simplify tiresome modelling of chaotic communication systems, for example, those that provide maximum range by increasing the signal length.

Filtering and Detection of Ultra-Wideband Chaotic Radio Pulses with a Matched Frequency-Selective Circuit

An approach is proposed to the filtering of an additive mixture of ultra-wideband chaotic signals and white Gaussian noise, in order to retrieve the useful signal in the receiver. The role of the filter is performed by a passive frequency-selective circuit, identical to the one involved in the formation of oscillations in the chaos generator. A mathematical model of a modulating chaos generator, detecting and receiving a sequence of ultra-wideband chaotic radio pulses in a noisy channel is designed. For the receiver of sequences of symbols encoded by chaotic radio pulses with 2- and 4-position modulation, the bit error ratio as a function of the noise level and the pulse duration is estimated numerically.

Analytical Model of an Energy Detector for Ultra-Wideband Chaotic Communications

For the ultra-wideband chaotic radio pulses an analytical model of an energy detector is designed and closed-form expressions for the optimal threshold and the detection probabilities are derived. The analytical solution is compared with the results of the numerical simulation. The model proves to be well-suited for the chaotic radio pulses with large base B (or processing gain, or the number of freedom degrees), namely, B ≥ 100. Potential applications areas of the proposed model are ultra-wideband communications with chaotic pulse carriers, e.g., ultra-wideband systems of 802.15.x standards, and multi-element chaotic communication systems.

Измерение мощности сверхширокополосного хаотического сигнала для решения задач определения расстояния и позиционирования

A method increasing the accuracy of distance measurements using an ultra-wideband chaotic radio pulses, intended for application in wireless sensor networks is proposed. It was shown that the relative error of distance measurement in the experimental test bench is within 5-9%.

Detection of Chaotic Radio Pulses Using an Ensemble of Envelope Detectors

In this paper, we study the possibility of detecting ultrawideband chaotic radio pulses using an ensemble of incoherent receivers based on envelope detectors. An analytical expression for the reception error probability as a function of the signal-to-noise ratio at the input of the envelope detector is obtained. The sensitivity of radio pulse detection (in terms of the signal-to-noise ratio) is shown to improve in proportion to the number of detectors.

Обнаружение хаотических радиоимпульсов с помощью ансамбля детекторов огибающих

Detection of ultrawideband chaotic radio pulses with ensemble of noncoherent receivers based on envelope detectors is investigated. Analytical solution is derived for the detection error probability as a function of signal-to-noise ratio at the detector input. The sensitivity of the radio pulse detection (by signal-to-noise ratio) is shown to increase in proportion to the number of detectors.

Эксперимент по определению времени прохождения сверхширокополосных хаотических радиоимпульсов через многолучевой канал

Here we describe experimental measurement results on the time of propagation of 3–5 GHz ultra-wideband chaotic radio pulses through multipath wireless channel. The accuracy of measuring the propagation time of ultra-wideband chaotic radio pulses by their envelope is evaluated. The achieved accuracy is sufficient for solving the problem of measuring the distance between objects and their localization in space in the industrial and office environments.

Measuring the Distance between an Emitter and a Receiver in the Wireless Communication Channel by Ultrawideband Chaotic Radio Pulses

The possibility of wireless distance measurement using ultrawideband chaotic radio pulses on the basis of the statistical signal analysis is discussed. The results of experimental verification of the proposed approach are reported.

Ultra-wideband chaotic radio pulse reception in the case of inter-pulse interference

The problem of receiving ultra-wideband (UWB) chaotic radio pulses of microwave band that passed through a multipath channel is considered. Based on measurements of UWB chaotic radio pulse propagation through a real wireless channel, a method for reception is proposed that is not affected by interpulse interference.

Wireless distance measurement by means of ultra-wideband chaotic radio pulses

A method for wireless distance measurement using ultrawideband chaotic radio pulses based on statistical analysis is proposed. Experimental results are discussed.

Multimedia sensor networks based on ultrawideband chaotic radio pulses

The requirements to transceivers, which are intended for multimedia data transmission in wireless sensor networks, and existing system characteristics are discussed. Ultrawideband wireless systems based on direct chaotic data transmission are analyzed to reveal the prospects of their application to multimedia sensor networks. The results obtained during experimental studies into video data-flow transfer, which are performed in the point-to-point mode with the use of radio relaying and through-wall transmission, are presented.

Propagation of ultrawideband chaotic radio pulses through the slits of metal surfaces

The leakage of ultrawideband (UWB) chaotic radio pulses through the defects (holes, slits, cracks, etc.) of metal surfaces-an urgent problem arising from their application as information carriers in wireless sensor networks-is investigated. Experiments with UWB chaotic radio pulses leaking from the slits of metal surfaces are described, and the experimental results are analyzed. The signal attenuation has been estimated when chaotic radio signals propagate through slits of different size.

Determination of the difference between the arrival times of a chaotic radio pulse at two receivers based on the cross-correlation of of the pulse envelopes

The problem of positioning with the use of ultra-wideband chaotic radio pulses is considered. A method for determination of the difference of signal arrival times based on the cross-correlation function of the envelope of chaotic radio pulses is proposed and studied. It is demonstrated that this method provides an error of estimation of the difference of signal arrival times that is inverse proportional to the frequency band of the radio-pulse envelope. It is found that the noise stability of the method is improved with as the suration of the chaotic radio pulse increases.

Noise immunity of the wireless communications scheme based on ultrawideband chaotic radio pulses in multipath channels

The problem of determining the noise immunity of wireless data transmission based on ultrawide-band (UWB) chaotic radio pulses in the multipath channel with white noise is substantiated. The results have been calculated via numerical simulation using the multipath channel models describing UWB signal propagation in rooms of different classes at distances as long as several tens of meters. The direct chaotic communications method is shown to have the noise immunity high enough to employ this scheme in practical wireless applications where information is transmitted under severe conditions of multipath propagation. In this case, the ultimate data transfer rates are found to 25 Mb/s.

Compensation of a narrowband interference in an ultrawideband communication system based on chaotic radio pulses

The influence of narrowband signals on incoherent reception of ultrawideband chaotic radio pulses in direct chaotic communication (DCC) system is considered. A method for compensating the influence of narrowband signals on the characteristics of this system after incoherent reception of chaotic radio pulses is proposed. The proposed solution enables one to compensate a narrowband signal, preserving the possibility to determine chaotic radio pulses at corresponding time positions. The dependence of the probability of an error per bit on the spreading ratio of chaotic radio pulses is established.