RU113100U1 - RADIO SYSTEM WITH AUTONOMOUS POWER SUPPLY TRANSMITTER FOR LONG-TERM TRANSMISSION OF DISCRETE INFORMATION - Google Patents

Abstract

1. A radio system designed for long-term transmission of discrete information in an urban environment over distances of up to 1 km, consisting of a transmitter and a receiver, including a series-connected high-frequency path, an amplitude detector and a demodulation unit, characterized in that a pulse a signal with a duration of about 1 μs, the required spectrum width of which is provided by means of wideband frequency modulation of the pulse carrier frequency. ! 2. The radio system according to claim 1, characterized in that a filter with a tunable frequency characteristic is additionally included in the high-frequency channel of the receiver for rejection of powerful narrow-band interference. ! 3. The radio system according to claim 1, characterized in that to increase the noise immunity of receiving pulsed signals in a multipath channel between the amplitude detector and the demodulation unit, an integrating filter is included in the receiver, which makes it possible to take into account the energy of all received beams.

Description

The proposed radio system relates to one-way communication systems designed to transmit discrete information in urban conditions at distances up to 1 km.

From the technical literature there are a large number of options for building radio systems to work in these conditions. Most of them use continuous sinusoidal oscillations modulated by a discrete informational sequence for some parameter. A feature of the transmission of information in urban conditions is the presence of multipath propagation of radio waves, which significantly reduce the noise immunity of reception and, with this method of constructing a radio system, require the use of an increased power transmitter. This, in turn, leads to an increase in energy consumption by the transmitter from an autonomous power source and to a decrease in operating time.

To combat the multipath propagation of radio waves, it is proposed to use broadband signals whose spectrum width significantly exceeds the amount required to transmit information at a given speed. The most common variant of broadband signals are continuous sinusoidal oscillations with phase shift by π radian according to the law of the periodic pseudo-random M-sequence. At the same time, it is possible to significantly No. 16/16 / C1 / 1/2060

reduce the power emitted by the transmitter, but the high complexity of the transmitter circuit and the low efficiency of the micropower transmitter do not significantly reduce energy consumption.

You can increase the efficiency of the transmitter by switching to a pulsed mode of operation. Known variants of radio systems with ultrashort (ultra-wideband) pulses. Closest to the claimed radio system may serve as a radio system described in the collection of reports of the All-Russian scientific conference "Ultra-wideband signals in communication radar and acoustics." / I.Ya. Immoreev, A.A. Sudakov, Ultra-wideband noise-immune covert communication system with a high data rate. /

In this system, discrete information was transmitted by pulses of about 1 ns duration. The clock frequency of the pulses was 2 MHz. Amplitude manipulation with a passive pause was used. The working frequency band was in the range of 0.4-2 GHz.

To ensure high-quality information transmission over a distance of 1 km, the peak power of pulses with such a duration should be at least 10 watts. Pulse generation requires direct current energy sources with a voltage of about 100 V. As a result, the efficiency of the transmitter becomes unacceptably small.

In addition, the system did not provide for the possibility of rejecting narrowband interference that may appear in the frequency band of a useful broadband signal; the receiver was designed to receive only one main beam, that is, there was no block of energy storage from several rays.

Information is transmitted in the proposed radio system with an autonomous transmitter power supply for long-term transmission of discrete information by pulses of significantly longer durations of about 1 μs, and the necessary spectrum width is provided by means of broadband frequency modulation of the carrier frequency No. 16/16 / C1 / 1/2060

pulses according to arbitrary law. As a result, the peak power of the emitted pulses decreases to about 10 mW. This allows you to build a transmitter with relatively low power consumption from an autonomous power source, on the one hand, and, at the same time, with high efficiency.

In the proposed radio system, information can be used either amplitude modulation with a passive pause, or one of the known options for temporal modulation (modulation by the temporal position of the emitted pulses).

The passband of the radio frequency filters of the receiver is chosen equal to the width of the spectrum of the emitted radio pulses. For rejection of powerful narrow-band interference, a tuner with a tunable frequency response is included in the high-frequency path of the receiver, which can "cut out" one or more areas affected by the interference. Changing the frequency response of the filter is possible both in manual mode and automatically using the adaptation mode. After amplitude detection, the received pulses are passed through an integrating filter. The filter integration time is chosen equal to the duration of the received pulses, taking into account the increase in duration due to multipath propagation. As a result, the noise immunity of the reception is comparable to the potential noise immunity of the reception of broadband signals in the multipath channel. The signal from the output of the filter-integrator is fed to the demodulation unit, the circuit of which corresponds to the type of modulation in the transmitter. At the output of the demodulation block, a sequence of binary signals corresponding to the transmitted information is formed. The temporary mode of operation of the demodulation unit is determined by the signals received from the clock synchronization unit.

The figure No. 1 shows the structural diagram of the transmitter of the proposed radio system, and the figure No. 2 shows the structural diagram of the receiver. The number 1 in the figure No. 1 designates the source of the binary information signal, No. 16/16 / C1 / 1/2060

the output voltage of which modulates the pulse signal in amplitude or time position. Numeral 2 denotes a pulse frequency modulated radio signal generator, and numeral 3 denotes a transmitting antenna.

In figure 2, the number 4 indicates the receiving antenna, the number 5 is a high-frequency amplifier, the number 6 is a tunable notch filter, and the number 7 is an amplitude detector. The number 8 in this figure indicates the low-pass filter integrator, and the number 9 is the demodulator of the information sequence of signals with a clock synchronization block. The number 10 denotes the chain along which the received binary sequence is transmitted.

The construction of a radio system is possible using standard radio devices.

Claims (3)

1. A radio system designed for long-term transmission of discrete information in urban conditions at distances up to 1 km, consisting of a transmitter and a receiver including a series-connected high-frequency path, an amplitude detector and a demodulation unit, characterized in that a pulse is used to obtain a high transmitter efficiency a signal with a duration of about 1 μs, the necessary spectrum width of which is provided by means of broadband frequency modulation of the carrier frequency of the pulse. 2. The radio system according to claim 1, characterized in that for the rejection of powerful narrowband interference, a filter with a tunable frequency response is additionally included in the high-frequency path of the receiver. 3. The radio system according to claim 1, characterized in that to increase the noise immunity of receiving pulse signals in the multipath channel between the amplitude detector and the demodulation unit, an integrating filter is included in the receiver, allowing to take into account the energy of all received beams.