RU2798490C1 - Radio-photon fibre-optical communication system (embodiments) - Google Patents

Abstract

FIELD: optical communication; information transmission technology.

SUBSTANCE: invention can be used to create a new generation of fibre-optic communication systems. The technical result is achieved due to the fact that the radio-photonic fibre-optic communication system, which includes a series-connected optical transmitter, an electro-optical modulator, an optoelectronic receiver, an analog-to-digital converter and a digital demodulator, has optical splitters, (n-1) electro-optical modulators and electronic adder introduced, a broadband laser emitting at n wavelengths is used as an optical transmitter, the outputs of which are connected to the inputs of n electro-optical modulators using a fibre optic cable containing n optical fibres, according to the number n wavelengths of the broadband laser radiation, the optoelectronic receiver is made in form of a matrix with n sensitive elements, n outputs of electro-optical modulators are optically coupled with the help of a fibre-optic cable to n sensitive elements of an optoelectronic receiver, the outputs of which are connected to the multi-channel input of the adder, the output of which is connected to the input of an analog-to-digital converter connected to a digital demodulator, n optical carriers from the output of a broadband laser are supplied to the optical inputs electro-optical modulators, and the same information radio signal or n different information signals are fed in parallel to their n modulating inputs.

EFFECT: increase of noise immunity of a radio-photon fibre-optic communication system, increase of the volume of transmitted information signals and reduction of weight and size dimensions of the system’s transmitting part.

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Description

The invention relates to the technique of optical communication and information transmission and can be used to create a new generation of fiber-optic communication systems.

Known fiber-optic transmission system (FOTS) information [1. Fiber-optic communication line. Patent RU 141884, publ. 06/20/2014; 2. Multi-channel fiber-optic communication system. Patent RU 2134491, publ. 10.081999; 3. Transceiver of a fiber-optic communication line. Patent RU 2407168, publ. 12/20/2010; 4. Radio photonic transmission path for transmitting high-power broadband signals and efficient antenna excitation. Patent RU 2716269, publ. 03/11/2020]. The analogues contain a series-connected optical transmitter, an optical transmission medium of an optical signal, for example, in the form of an optical cable, an optoelectronic receiver and a terminal device.

The closest claimed radio-photonic digital fiber-optic communication system is a digital optical communication system described in the article [Volkov S.A., Ovsyankin S.V. Peculiarities of demodulation of modern optical signals // Technique of radio communication. - 2016. - No. 1. - S. 64-71.], which includes an electro-optical modulator and an optical transmitter, an optoelectronic receiver, an analog-to-digital converter and a digital demodulator connected in series, while the optical output of the modulator and the input of the optoelectronic receiver are connected by a fiber-optic cable.

The disadvantages of the prototype are the use of optical radiation of a single carrier frequency and the inability to use multiple carriers often for transmitting and receiving information broadband radio signals, which does not provide the required signal-to-noise ratio in the received message.

The objective of the invention is to increase the noise immunity of a radio-photonic fiber-optic communication system, increase the number (density) of transmitted information signals and reduce the overall dimensions of its transmitting part.

The technical result, aimed at improving the noise immunity of the communication system, is achieved due to the fact that in the radio-photonic fiber-optic communication system, which includes serially connected optical transmitter, electro-optical modulator, optoelectronic receiver, analog-to-digital converter and digital demodulator, the optical transmitter is made in the form broadband laser emitting at n wavelengths, connected via a fiber-optic cable consisting of n optical fibers, with an electro-optical modulator made in the form of n electro-optical modulators at n wavelengths, modulated by the same information signal, n outputs of electro-optical modulators with using a fiber-optic cable, they are optically coupled to an optoelectronic receiver made of a matrix with n sensitive elements, the outputs of which are connected to the multichannel input of the added adder, the output of which is connected to the input of an analog-to-digital converter connected to a digital demodulator, while the adder is configured to linear summation useful signals and RMS summation of internal noise.

The number of electro-optical modulators, the number of sensitive elements of the optoelectronic receiver, the number of optical fibers in the fiber optic cable connecting the modulator unit to the laser output, and the number of optical fibers in the fiber optic cable connecting the outputs of the electro-optical modulators with the sensitive elements of the matrix optoelectronic receiver is equal to the number of wavelengths of the broadband laser radiation .

The use of n carrier frequencies of optical radiation to transmit one (responsible) information signal provides an increase in the signal-to-noise ratio in the information message at the output of the adder by the square root of n times.

The technical result, aimed at increasing the density of information transmission, is achieved due to the fact that in the radio-photonic fiber-optic communication system, which includes a series-connected optical transmitter, an electro-optical modulator, an optoelectronic receiver, an analog-to-digital converter and a digital demodulator, the optical transmitter is made in in the form of a broadband laser emitting at n wavelengths, connected via a fiber-optic cable consisting of n optical fibers, with an electro-optical modulator made in the form of n electro-optical modulators at n wavelengths modulated by various information signals, n outputs of electro-optical modulators using fiber -optical cable is optically coupled with an optoelectronic receiver made of a matrix with n sensitive elements, the outputs of which are connected to the inputs of a multichannel analog-to-digital converter connected to a multichannel digital demodulator, optical carriers of n wavelengths are fed to the optical inputs of the electro-optical modulators, and modulating (electrical) ) inputs of n electro-optical modulators are fed in parallel with n different information signals.

At the same time, in the claimed versions of the radio-photonic fiber-optic communication system, the number of electro-optical modulators, the number of sensitive elements of the optoelectronic receiver, the number of optical fibers in the fiber-optic cable connecting the modulator block to the laser output, and in the fiber-optic cable connecting the outputs of the electro-optical modulators with sensitive elements of the matrix optoelectronic receiver, is equal to the number of wavelengths of radiation of a broadband laser.

, где n - количество суммируемых сигналов, смешанных с аддитивными внутренними шумами матричного оптоэлектронного приемника.The electronic adder is a linear analog adder that sums the signals linearly and the internal noise sums rms, as a result of which the signal-to-noise ratio in the received message at the output of the adder increases by

, where n is the number of summed signals mixed with additive internal noise of the matrix optoelectronic receiver.

The inventive radio-photonic fiber-optic communication system in the first embodiment is illustrated by a functional diagram shown in figure 1. The diagram includes the following functional elements: 1 - broadband laser; 2, 6; - fiber optic cable; 3, 7 - optical splitter; 4 - source of information broadband radio signal; 5 (5.1, ..., 5.n) - a block of n electro-optical modulators; 8 (8.1, ..., 8.n) - matrix optoelectronic receiver; 9 - electronic adder; 10 - multichannel analog-to-digital converter (ADC); 11 - digital demodulator, - at the same time, the output of the optical transmitter - a broadband laser - is connected to the inputs of n electro-optical modulators using a fiber optic cable containing n optical fibers, according to the number n wavelengths of the broadband laser radiation, the optoelectronic receiver is made matrix with n sensitive elements , n outputs of electro-optical modulators are optically coupled with the help of a fiber-optic cable to n sensitive elements of an optoelectronic receiver, the outputs of which are connected to the multichannel input of the adder, the output of which is connected to the input of an analog-to-digital converter connected to a digital demodulator, and to the modulating (electrical) inputs n electro-optical modulators are fed in parallel with the same information broadband radio signal.

The inventive radio-photonic fiber-optic communication system in the second version is illustrated by a functional diagram shown in figure 2. The diagram includes the following functional elements: 1 - broadband laser; 2, 6; - fiber optic cable; 3, 7 - optical splitter; 4 - source of information broadband radio signal; 5 (5.1, ..., 5.n) - a block of n electro-optical modulators; 8 (8.1, ..., 8.n) - matrix optoelectronic receiver; 10 - multichannel analog-to-digital converter (ADC); 11 - digital demodulator, - at the same time, the output of the optical transmitter - a broadband laser - is connected to the inputs of n electro-optical modulators using a fiber optic cable containing n optical fibers, according to the number n wavelengths of the broadband laser radiation, the optoelectronic receiver is made matrix with n sensitive elements , n outputs of the electro-optical modulators are optically coupled with the help of a fiber-optic cable to n sensitive elements of the optoelectronic receiver, the outputs of which are connected to the multichannel input of the adder, the output of which is connected to the input of the analog-to-digital converter connected to the digital demodulator, and to the modulating inputs of the "electro-optical modulators the same information broadband radio signal is fed in parallel.

The inventive radio-photonic fiber-optic communication system (in both versions) operates as follows (see Fig. 1, 2). Laser radiation of a broadband laser 1, consisting of n wavelengths, using a fiber optic cable 2, consisting of n optical fibers, and a splitter 3, modulated by an information signal 4 in a block of n electro-optical modulators 5, at n wavelengths, over a fiber optic cable 6 and splitter 7 are supplied in parallel to n sensitive elements (SE) 8.1, ..., 8.n of the matrix optoelectronic receiver 8, which converts laser radiation into an electrical signal. In the electronic adder 9, a linear summation of useful signals and an rms summation of internal noise are performed, as a result of which the signal-to-noise ratio in the received message rises to the square root of the number of sensing elements n of the receiver. The ADC 10 digitizes the information signal and demodulates it in a digital AND demodulator, the output of which undergoes further processing (eg automatic recognition or decoding).

When using a source of n information signals u ₁ , ..., u _n (see Fig. 2) due to the use of n optical carriers generated by a broadband laser, an increase in the information transmission density by n times is achieved. When using several tens to hundreds of carriers with the help of broadband lasers developed to date, the transmission rate can actually be increased by several tens to hundreds of times [1–8].

Thanks to the use of a broadband laser emitting, for example, at 144 wavelengths, and a 144-fiber optical cable, an increase in the signal-to-noise ratio in the received message by 12 times, and an increase in the information transmission density by 144 times, is achieved.

Broadband lasers emitting in the infrared spectral range from 1.7 to 20 μm [1–8], as well as fiber-optic cables providing the attenuation coefficient, created to date (at the P.N. Lebedev Physical Institute of the Russian Academy of Sciences in the infrared range less than 0.1 dB/km [9-11], open up broad prospects for the creation of highly efficient backbone fiber-optic information transmission systems.

The technical result consists in increasing the noise immunity of the proposed fiber-optic communication system by increasing the signal-to-noise ratio in the received message and by increasing the density of transmitted messages. In addition, the use of one broadband laser, instead of n single-frequency lasers, for the transmission of information signals significantly reduces the weight and size parameters of the transmitting part of the FOTS.

List of used literature

1. Ionin A.A., Kinyaevsky I.O., Klimachev Yu.M. et al. Broadband IR laser source (~1.7 - 20 μm) // Vseross. forum with international participation "Academic Zhukovsky Readings", November 23-25, 2021, Voronezh. - Forum materials. - Voronezh: VUNTS VVS "VVA". - 2022. - Part 3.

2. Andreev Yu. t al. Quantum Electronics. - 2013. No. 43, p. 139.

3. Budilova O.V. et. al. Optics Letters. - 2016. - No. 41, p. 111.

4. Ionin A.A., Kinyaevskiy I.O., Klimachev Yu. M. et al. Laser Phys. - 2018. - No. 28.025401, 4 pp.

5. Ionin A.A. et al. Optics Letters. - 2018. - No. 43, p. 4358-4361.

6. Budilova O.V. et. al. Optics Communications. - 2016. - No. 363, p. 26.

7. Ionin A.A., Kinyaevskiy I.O., Klimachev Yu. M. et al. Opt. express. - 2019. - Vol. 27. - No. 17, p. 24353.

8. Budilova O.V. et. al. Optics Communications. - 2015. - No. 345, p. 163.

9. www.sphotonics.ru (Accessed 17.01.2022).

10. www.asimp.ru (references - 01/17/2022).

11. Larin Yu.T. Glasses for the manufacture of optical fibers and cables. - JSC VNII KP. - Portal "Radioelectronics and Telecommunications". - www.infomost, www.hieperline, www.lean/theorva-prakt (Accessed 01/19/2022).

Claims (2)

1. A radio-photonic fiber-optic communication system, which includes a series-connected optical transmitter, an electro-optical modulator, an optoelectronic receiver, an analog-to-digital converter and a digital demodulator, characterized in that the optical transmitter is made in the form of a broadband laser emitting at n wavelengths, connected through a fiber-optic cable consisting of n optical fibers, with an electro-optical modulator made in the form of n electro-optical modulators at n wavelengths modulated by the same information signal, n outputs of the electro-optical modulators are optically coupled with an optoelectronic receiver using a fiber-optic cable , made matrix with n sensing elements, the outputs of which are connected to the multichannel input of the added adder, the output of which is connected to the input of the analog-to-digital converter connected to the digital demodulator, while the adder is configured to linearly sum the useful signals and RMS summation of internal noise. 2. A radio-photonic fiber-optic communication system, which includes a series-connected optical transmitter, an electro-optical modulator, an optoelectronic receiver, an analog-to-digital converter and a digital demodulator, characterized in that the optical transmitter is made in the form of a broadband laser emitting at n wavelengths, connected through a fiber-optic cable consisting of n optical fibers, with an electro-optical modulator made in the form of n electro-optical modulators at n wavelengths modulated by various information signals, n outputs of the electro-optical modulators are optically coupled with an optoelectronic receiver made by a matrix with n sensitive elements, the outputs of which are connected to an analog-to-digital converter, made multi-channel and connected to a digital demodulator, made multi-channel.

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