RU2544837C1 - Method of transmitting information using ultra-broadband pulsed signal - Google Patents

Abstract

FIELD: radio engineering, communication.

SUBSTANCE: method of transmitting information using an ultra-broadband pulsed signal comprises using a considerable part of the centimetre band from 3.5 to 10.5 GHz, using a switch as the shaping circuit of a transmitter based on fast-recovery drift diodes which enables to generate a short pulse, excluding spectral signal components beyond the bandwidth from 3.5 to 10.5 GHz, matching the periodic information flow with a quasi-periodic transmission mode, applying pulses obtained by passing the short pulse through a band-pass filter, matching the transmission of pulses at temporal positions with a quasi-periodic transmission mode, performing information modulation using time shift of the pulse by the time equal to $$\frac{1}{8f_l},$$

where f_l is the lower cut-off frequency of the shaping filter of the transmitter.

EFFECT: providing a high rate of transmitting information in conditions without intersymbol interference when transmitting information using an ultra-broadband pulsed signal.

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Description

The invention relates to the field of telecommunications, namely to digital radio communications and can be used to create an ultra-wideband pulse transmitter.

Known full-duplex communication system [1] in which the following method of transmitting information by an ultra-wideband pulse signal is implemented:

1) Short pulses are applied in the form of derivatives of the Gauss functions - the Gaussian monocycle.

2) The period of repetition of short pulses of the order of 1 ms is set.

3) The time-pulse modulation of the ultra-wideband signal is used, while the information is embedded in the presence or absence of a temporary shift of the pulse relative to the reference point by a quarter of the pulse duration.

A disadvantage of the known method of transmitting information by an ultra-wideband pulse signal is that:

1) Time-frequency resource is used inefficiently .;

2) The maximum transmission rate of information packages is not provided.

3) The waveform and the position of the zeros in the time domain are not taken into account when the signal passes through the limiting filters that are consistent with the allowed frequency range.

Closest to the technical implementation of the device that implements this method is given in the thesis of Korotkov D.A. "Development and research of powerful nanosecond pulse generators based on drift diodes with a sharp recovery and dynistors with deep levels" Physics and Technology Institute. A.F. Ioffe RAS [2-4]. However, this device has inherent disadvantages associated with the lack of an output forming band-pass filter and the low transmission rate of information packages.

According to [5], for a fixed frequency band defined for ultra-wideband signals (2.85-10.6 GHz in the Russian Federation) and strict limits on the level of out-of-band emissions, each pulse must pass through a high-pass filter with the corresponding cutoff frequencies. At the same time, the duration of transients increases significantly. To ensure signal transmission without distortion (there is no intersymbol interference), it is necessary to transmit pulses with a repetition period of 4-5 pulse durations.

The technical result of the invention is the provision of a high transmission rate of information packages in the absence of intersymbol interference when transmitting information with an ultra-wideband pulse signal.

, где f_н - нижняя частота среза формирующего фильтра передатчика, при этом для передачи сигнала используют значительную часть сантиметрового диапазона частот от 3,5 до 10,5 ГГц полосы радиочастот, в которой разрешено применять сверхширокополосный сигнал в Российской Федерации согласно "ГОСТ Р 5001692 [6]; в качестве основы передатчика используются дрейфовые диоды с резким восстановлением, которые позволяют получать короткий импульс; определяют структуру сигнала как последовательность следования импульсов; в качестве формирующей схемы передатчика используют ключ на основе дрейфовых диодов с резким восстановлением, который позволяет сформировать короткий импульс со спектром, равномерным в полосе от 3,5 до 10,5 ГГц; используют выходной фильтр высокого порядка, который позволяет исключить спектральные составляющие сигнала за пределами полосы от 3,5 до 10,5 ГГц; используют устройство управления передатчика, которое согласует периодический информационный поток с квазипериодическим режимом передачи. В качестве средства согласования периодического потока выступает устройство управления с функцией хранения данных (память). Периодический поток информационных посылок заносится в память, а само устройство замыкает ключ по алгоритму, отражающему квазипериодический режим формирования импульсов и вид информационной модуляции.The technical result of the new method is achieved by applying pulses obtained by passing a short pulse with a uniform spectrum in the filter frequency band through the bandpass filter, the transmission of pulses at temporary positions is coordinated with a quasiperiodic transmission mode, and information modulation is carried out using a temporary pulse shift by time, equal $$\frac{\mathrm{one}}{8f_n}$$

, where f _n is the lower cut-off frequency of the transmitter forming filter, while a significant part of the centimeter frequency range from 3.5 to 10.5 GHz radio frequency band is used for signal transmission, in which it is allowed to use an ultra-wideband signal in the Russian Federation according to GOST R 5001692 [ 6]; as the basis of the transmitter, sharp recovery drift diodes are used that allow you to receive a short pulse; define the signal structure as a sequence of pulses; as the forming circuit They use a key based on drift diodes with a sharp recovery, which allows you to generate a short pulse with a spectrum uniform in the band from 3.5 to 10.5 GHz; use a high-order output filter that eliminates the spectral components of the signal outside the band from 3, 5 to 10.5 GHz; use a transmitter control device that matches the periodic information stream with the quasiperiodic transmission mode. As a means of matching the periodic flow acts as a control device with a data storage function (memory). A periodic flow of information packages is stored in the memory, and the device itself closes the key according to an algorithm that reflects the quasiperiodic mode of pulse formation and the type of information modulation.

In order for the information to be transmitted by an ultra-wideband signal, the information signal in the form of a short pulse with a uniform spectrum in the filter frequency band passes through the band-pass filter, and the transmission of pulses at temporary positions is coordinated with the quasiperiodic transmission mode, information modulation is carried out using a time shift.

The following types of quantized pulse modulations can serve as information modulation - quantized amplitude-pulse modulation, quantized phase-pulse modulation.

The essence of the method is illustrated in FIG. 1 - 5, which shows the waveform obtained by a full-duplex communication system, and an ultra-wideband pulse signal obtained by an ideal band-pass filter.

In FIG. 1 is a schematic diagram of a transmitter based on drift diodes with a sharp recovery (DDRV). In the initial state, the key K is off, the capacitor C2 is discharged. When K is switched on in the primary winding of a pulse transformer T1, the discharge current of capacitor C1 is switched. At the same time, the current flowing through the secondary circuit of the transformer is direct for the DDRV (the inclusion current of the DDRV). As a result, the capacitor C2 is charged and the minority carriers are accumulated in the structure of the DDRV. At the end of the charging process of the capacitor C2, the core of the transformer T1 is saturated, which leads to a sharp decrease in the inductance of its secondary winding. The capacitor C2 is quickly discharged, while the current flowing in the circuit "C2-DDRV" is the reverse for DDRV (off current). During the shutdown current flow, the accumulated charge of minority carriers is removed from the DDRV structure, the value of which, due to the short duration of the accumulation process, is actually equal to the charge introduced at the stage of passing the on-pulse current. After releasing the base region of the DDRV from the charge of minority carriers, the shutdown current is maintained due to the output of the main carriers. In this case, the electrical conductivity of the DDRV decreases sharply and becomes significantly less than the electrical conductivity of the load resistance R _H. As a result, there is a fast switching of the current from the DDDR to the load R _H.

Thus, it is the discharge of the storage element for a very short period of time (opening and closing the key) that forms the ultra-wideband pulse.

In FIG. 2 shows a waveform obtained by a full duplex communication system. Such a signal, limited in the time domain, has an unlimited spectrum with side lobes, and when it is used, the time-frequency resource is used inefficiently.

In FIG. 3a shows a block diagram of an ideal band-pass filter (IPF). Since the IAP is a linear device, the principle of superposition is applicable to it. In FIG. 3b is a block diagram of an IPF, consisting of two ideal low-pass filters (IFPS), while the input signal is simultaneously fed to block 2 of the LPF f _in , where f _in is the upper cut-off frequency of the forming filter of the transmitter, and block 3 of the LPF f _n , output of block 2 and the output of block 3 is connected to a subtractor, the output of which is the output of an equivalent structural circuit.

на дельта-импульс [6, 7].In FIG. Figure 4 shows the response of the IPF obtained by mathematical modeling with the ratio of the cutoff frequencies $$\frac{f_{\mathrm{at}}}{f_n}=3$$

per delta pulse [6, 7].

In FIG. Figure 5 shows the structure of an ultra-wideband pulse signal that provides the maximum transmission rate of information packets, while the time-frequency resource is fully utilized, intersymbol interference is absent, and out-of-band emissions are minimal.

In contrast to the information modulation known in this method, and the transmission of pulses at positions in accordance with the repetition period is carried out taking into account the need to ensure a quasiperiodic mode of operation of the transmitter (transmission of two packages, then a pause for the duration of the transmission of two packages and again the transmission of two information packages) . In this case, it is advisable to use a signal with the base of the code a = 2, since such a signal is more easily consistent with the structure proposed in the method.

In the simplest case, with quantized amplitude manipulation with the base of code 2, the key will be closed and, accordingly, generate an impulse only for transmitting “1”, with “0” an impulse will not be generated, and the key can be triggered only at specified (quantized) temporary positions . The control device, first of all, is necessary in order to group information in the form of zeros and ones from an arbitrary source according to the principle - two temporary positions where the key can be triggered, then two temporary positions where the key cannot be triggered. The cycle repeats.

In this method, for the first time, the quasiperiodic mode of operation of the transmitter is determined (transmission of two packages, then a pause for the duration of transmission of two packages and again transmission of two information packages), which allows transmitting information packages at a speed equal to twice the frequency band.

This method is implemented in the frequency band of 2.85-10.6 GHz. The use of this frequency band is due to a decision of the State Radio Frequency Commission [8], which prohibits the use of an ultra-wideband signal in the band below 2.85 GHz and above 10.6 GHz. To eliminate the frequency components outside the allowed band, it is necessary to use a high-order bandpass filter with cutoff frequencies f _â = 10.6 GHz and f _í = 2.85 GHz. An equivalent circuit of such a filter is a circuit consisting of two low-pass filters with cut-off frequencies f ₁ = 2.85 GHz and f ₂ = 10.6 GHz and a subtractor (Fig. 3). In the time domain, the signal received when a δ-pulse passes through such a filter is described by the formula:

», ни к классу узкополосных сигналов, определенных традиционной радиотехникой, кроме того, добиться периодической или квазипериодической передачи можно только при целочисленном отношении частот среза.The signal described by expression (1), when f _â comparable to f _í, does not belong to the class of signals " $$\frac{\sin \left(x\right)}{x}$$

”, Nor to the class of narrow-band signals defined by traditional radio engineering, in addition, to achieve periodic or quasiperiodic transmission is possible only with an integer ratio of the cutoff frequencies.

позволяет наиболее полно задействовать весь разрешенный решением ГКРЧ диапазон радиочастот (от 3,5 до 10,5 ГГц).Condition $$\frac{f_{\mathrm{at}}}{f_n}=3$$

allows you to fully utilize the entire range of radio frequencies allowed by the SCRF solution (from 3.5 to 10.5 GHz).

The signal described by expression (1) with cutoff frequencies of 3.5 GHz and 10.5 GHz is shown in FIG. 4. Given the shape of the pulse and the position of the zeros in the time domain, it can be indicated that ensuring the maximum transmission speed of information packets in the absence of intersymbol interference is possible with quasiperiodic transmission (transmission of two packages, then a pause for the transmission time of two packages and again transmission of two information packages). In this case, the maximum transmission speed of the packages (V = 2Δf) is achieved and there is no intersymbol interference (Fig. 5).

The method of organizing the operation of an ultra-wideband pulse transmitter makes it possible to increase the transmission rate of information packets in the absence of intersymbol interference.

Bibliography

1. Full duplex communication system. U.S. Patent 5,687,169, Full duplex ultrawide-Band communication system and method, Larry W. Fullerton, 1997.

2. Korotkov D.A. The dissertation on the theme "Development and research of powerful nanosecond pulse generators based on drift diodes with a sharp recovery and dynistors with deep levels" Physics and Technology Institute. A.F. Ioffe RAS. Dis. for the degree of KTN special. 04/01/13, FSBI Physical-Technical Institute. A.F. Ioffe RAS, St. Petersburg, 2013, pp. 28-30.

3. Rozhkov A.V., Kozlov V.A. "Picosecond high-voltage drift diodes based on gallium arsenide", "Physics and Technology of Semiconductors", vol. 37, no. 12, 2003

4. Afanasyev A.V., Ivanov B.V., Ilyin V.A., Cardo-Sysoev A.F. and others. "Drift diodes with sharp recovery based on silicon carbide" // Mathematical All-Russian Conference of Microwave Electronics and Microelectronics, 2002 - S. 260-262.

5. Rudko A.S. Scientific and technical substantiation of the choice of class and parameters of an ultra-wideband signal for information support of a group space object // Military Academy of the Strategic Missile Forces named after Peter the Great. M., Dep. in CSIF MO, 2011.

6. "A way to organize the operation of an ultra-wideband pulse transmitter" 13th All-Russian Exhibition of Scientific and Technical Creativity of Youth, Moscow, All-Russian Exhibition Center, June 25-28, 2013

7. "Features of the formation of an ultra-wideband pulse signal in the conditions of frequency and power limitations." International Intersectoral Youth Science and Technology Forum. Competition of scientific and technical works and projects "Youth and the Future of Aviation and Cosmonautics. Moscow, All-Russian Exhibition Center, November 26, 2013.

8. Decisions of the state commission on radio frequencies No. 09-05-02 of March 19, 2009.

Claims (1)

The method of transmitting information by an ultra-wideband pulse signal, which consists in using a significant part of the centimeter frequency range from 3.5 to 10.5 GHz, using the key as a transmitter forming circuit based on drift diodes with a sharp recovery, allowing the formation of a short pulse, excluding spectral the components of the signal outside the band from 3.5 to 10.5 GHz, coordinate a periodic information stream with a quasiperiodic transmission mode, characterized in that the pulses are used, nnye short pulse by passing through a bandpass filter, coordinate the transmission of impulses in temporary positions with quasiperiodic transmission mode information modulation is performed using the time shift pulse at a time equal to $$\frac{\mathrm{one}}{8f_n}$$

where f _n is the lower cutoff frequency of the transmitter forming filter.

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