Modulator of signals from two message sources

Abstract

FIELD: communications.SUBSTANCE: devices for generating amplitude modulation (AM) signals, used in communications equipment. A low-frequency modulating signal source, an analog-to-digital transducer, a first additional adder, a third multiplier, an inverter, a third adder, an additional Hilbert transducer, a second additional adder, a fourth multiplier, a fourth adder, and an additional phase shifter are additionally introduced into the single-sideband modulator.EFFECT: formation of an AM signal, the sidebands of the spectrum of which contain information from a discrete information source and an analog information source.1 cl, 2 dwg

Description

[0001] The invention relates to devices for generating amplitude modulation (AM) signals and can be used in communication equipment used in networks for exchanging radar information between unmanned aircraft systems.

[0002] From the prior art, a digital method for generating single-sideband modulation (SSB) signals using a quadrature modulator is known (Signal generation and generation in military radio communications equipment. Part 1. Frequency synthesizers. Generation of radio signals: Textbook - St. Petersburg: VAS, 2022. 224 p.).

[0003] In Fig. 2.81, see (Signal generation and formation in military radio communication equipment. Part 1. Frequency synthesizers. Formation of radio signals: Textbook SPb.: VAS, 2022. - 224 p.), a quadrature modulator is shown that forms OM signals based on a digital method.In the known device, discrete samples of the low-frequency modulating signal (LFMS) ut, signal ut are fed from the discrete sample source (DSS) to the first inputs of the first and second multipliers, wherein the signal ut is fed to the first input of the second multiplier through a Hilbert transformer (HT), and discrete samples of the high-frequency carrier oscillation (HFCO) st are fed to the second input of the first and second multipliers, wherein the oscillation st is fed to the second input of the second multiplier through a high-frequency phase shifter, respectively, from the output of the first and second multipliers the resulting discrete samples of the signals s1t and s2t are fed to the first and second inputs of the adder, from the output of which discrete samples of the desired single-sideband modulation signal zt are obtained.

[0004] The disadvantage of this device is that the desired signal OM zt does not contain a constant component in the form of a pilot signal, which leads to reduced noise immunity for its reception without the construction of complex synchronization systems for its demodulation. Furthermore, the desired signal OM zt contains information from only one source.

[0005] The closest in essence to the claimed device is the “Device for generating a single-sideband modulation signal” (RU Patent No. 2798980, IPC H03K 5 / 00, Published: 06 / 30 / 2023 Bulletin No. 19).

[0006] The prototype device comprises a low-frequency modulating signal IDO, a PG, the first and second multipliers, the outputs of which are connected to the output of the adder, the output of which is the output of discrete samples of the desired OM signal, as well as a high-frequency modulating signal generator, the output of which is directly connected to the first input of the first multiplier, and through a phase shifter to the first input of the second multiplier, while the second and third adders and a direct current amplifier (DCA) with discrete samples of direct voltage at the output are introduced into the device, while the output of the low-frequency modulating signal IDO is connected to the first input of the second adder, and through the PG to the first input of the third adder, the second inputs of the second and third adders are connected to the DCA, and the outputs of the second and third adders are connected, respectively, to the second inputs of the first and second multipliers.

[0007] The disadvantage of the prototype device is that the desired signal contains data from only one source of discrete information.

[0008] The objective of the invention is to develop a device that makes it possible to form from an OM signal with an upper sideband of the spectrum and an OM signal with a lower sideband of the spectrum a resulting AM signal that simultaneously contains information from two sources, a source of discrete information and a source of analog information.

[0009] The technical result of the claimed device is the formation of an AM signal, the sidebands of the spectrum of which contain information from a discrete information source and an analog information source.

[0010] The technical result is achieved in that a modulator of signals from two sources of messages containing a series-connected source of discrete samples of a low-frequency modulating signal, a first adder and a first multiplier, a series-connected second adder and a second multiplier, as well as a Hilbert converter, the input of which is connected to the output of the source of discrete samples of a low-frequency modulating signal, a unity-level voltage generator, the output of which is connected to the second inputs of the first and second adders, a π / 2 phase shifter, a high-frequency carrier oscillation generator, the output of which is connected to the second input of the first multiplier and the input of the π / 2 phase shifter, as well as a resulting adder, the output of which is the output of the modulator, additionally contains a series-connected first additional adder, a third multiplier and an inverter,wherein the first input of the additional adder is connected to the output of the Hilbert converter, and the second input is connected to the output of the unit-level voltage generator, and the second input of the third multiplier is connected to the output of the π / 2 phase shifter, an additional source of a low-frequency modulating signal, an analog-to-digital converter, an additional Hilbert converter, a second additional adder and a fourth multiplier are connected in series, wherein the output of the analog-to-digital converter is also connected to the first input of the second adder, and the second input of the second additional adder is connected to the output of the unit-level voltage generator, as well as an additional π / 2 phase shifter, the output of which is connected to the second input of the fourth multiplier, and the device additionally comprises a third adder, the first and second inputs of which are connected to the first multiplier and inverter, respectively, a fourth adder,the first and second inputs of which are connected to the fourth multiplier and the second multiplier, respectively, while the output of the high-frequency carrier oscillation generator is also simultaneously connected to the input of the additional π / 2 phase shifter and the second input of the second multiplier, while the outputs of the third and fourth adders are connected to the first and second inputs of the resulting adder, respectively.

[0011] Due to the additional use of new blocks in the claimed device, as well as new connections between the new and old blocks, it is possible to form an AM signal, the sidebands of which contain information from different sources, from a discrete information source and an analog information source.

[0012] Let us explain the possibility of achieving the claimed technical result.

[0013] According to the prototype device, the generated OM signal has a pilot signal, making it similar to an AM signal. However, since the OM signal has only one block spectrum component (the upper sideband), it can only contain information from one source.

[0014] The introduction of additional blocks, in accordance with the claimed device, ensures the formation of an AM signal, which in the lower sideband of the spectrum contains information coming from an additional analog LFMS source.

[0015] This became possible due to the fact that the claimed device combines two quadrature modulators of OM signals, respectively with the upper and lower sidebands of the spectrum.

[0016] The claimed utility model is explained by drawings, which show: Fig. 1 - a structural diagram of a modulator of signals from two message sources, Fig. 2 - a module of the spectrum of an AM signal, formed in accordance with the claimed device, in the side bands of the spectrum of which information from different sources is contained.

[0017] The following designations are introduced in Fig. 1:

[0018] 1. Low-frequency modulating signal discrete sample source

[0019] 2. First adder

[0020] 3. First multiplier

[0021] 4. Additional low-frequency modulating signal source

[0022] 5. Analog-to-digital converter

[0023] 6. Second adder

[0024] 7. Second multiplier

[0025] 8. Hilbert Transformer

[0026] 9. First additional adder

[0027] 10. Third multiplier

[0028] 11. inverter

[0029] 12. Additional Hilbert Transformer

[0030] 13. Second additional adder

[0031] 14. Fourth multiplier

[0032] 15. Third adder

[0033] 16. fourth adder

[0034] 17. π / 2 phase shifter

[0035] 18. Additional π / 2 phase shifter

[0036] 19. Single-level voltage generator

[0037] 20. High-frequency carrier oscillator

[0038] 21. Resultant adder

[0039] The modulator of signals from two message sources consists of a series-connected source of discrete samples of a low-frequency modulating signal 1, a first adder 2 and a first multiplier 3, a series-connected additional source of a low-frequency modulating signal 4, an analog-to-digital converter 5, a second adder 6 and a second multiplier 7, a series-connected Hilbert converter 8, a first additional adder 9, a third multiplier 10 and an inverter 11, a series-connected additional Hilbert converter 12, a second additional adder 13 and a fourth multiplier 14, as well as a third adder 15, the first and second inputs of which are connected to the first multiplier 3 and the inverter 11, respectively, a fourth adder 16, the first and second inputs of which are connected to the fourth multiplier 14 and the second multiplier 7, respectively, a π / 2 phase shifter 17 and an additional phase shifter π / 2 18,the outputs of which are connected to the second inputs of the third 10 and fourth 14 multipliers, respectively, the unity-level voltage generator 19, the output of which is connected to the second inputs of the first adder 2, the first additional adder 9, the second additional adder 13 and the second adder 6, the high-frequency carrier oscillation generator 20, the output of which is connected to the second inputs of the first 3 and second 7 multipliers, as well as to the inputs of the π / 2 phase shifter 17 and the additional π / 2 phase shifter 18, wherein the output of the source of discrete samples of the low-frequency modulating signal 1 is connected to the input of the Hilbert converter 8, and the output of the analog-to-digital converter 5 is connected to the input of the additional Hilbert converter 12, the device also contains a resulting adder 21, the first and second inputs of which are connected to the outputs of the third 15 and fourth 16 adders, wherein its output is the output of the modulator.,

[0040] The blocks included in the general circuit of the modulator are connected by wires and contacts.

[0041] The claimed device operates as follows.

[0042] 1. From the source of discrete samples of the low-frequency modulating signal 1, the modulating signal is fed to the first input of the first adder 2 and through the Hilbert converter 8 to the first input of the first additional adder 9. A constant-level signal is fed to the second inputs of the first adder 2 and the first additional adder 9 from the unity-level voltage generator 19.

[0043] 2. Then the sum signal from the output of the first adder 2 is fed to the first input of the first multiplier 3, and from the output of the first additional adder 9 to the first input of the third multiplier 5.3.

[0044] 3. At the same time, the carrier oscillation from the output of the high-frequency carrier oscillation generator 20 is fed to the second input of the first multiplier 3 and, through the π / 2 phase shifter 17, is fed to the second input of the third multiplier 10.

[0045] 4. From the output of the first multiplier 3, the signal is fed to the first input of the third adder 15, and from the output of the third multiplier 10, the signal is fed through the inverter 11 to the second input of the third adder 15.

[0046] The use of inverter 11 ensures the formation of an OM signal with a lower sideband of the spectrum and a residual level of the carrier oscillation (pilot signal) at the output of the third adder 15, see Fig. 2.

[0047] 5. Simultaneously, from the additional source of low-frequency modulating signal 4, which is the second source of information, the signal is fed through the analog-to-digital converter 5 to the first input of the second adder 6 and through the additional Hilbert converter 12 to the first input of the second additional adder 13; a constant-level signal from the unity-level voltage generator 19 is simultaneously fed to the second inputs of the second additional adder 13 and the second adder 6.

[0048] 6. Next, the signal from the output of the second additional adder 13 is fed to the first input of the fourth multiplier 14, and from the output of the second adder 6, the signal is fed to the first input of the second multiplier 7. In this case, the carrier oscillation from the output of the generator 20. The high-frequency carrier oscillation generator 20 is fed to the second input of the second multiplier 7 and, through the additional π / 2 phase shifter 18, is fed to the second input of the fourth multiplier 14.

[0049] 7. Then, from the output of the fourth multiplier 14, the signal is fed to the first input of the fourth adder 16, to the second input of which the signal from the output of the second multiplier 7 is fed. As a result, at the output of the fourth adder 16, a signal OM with an upper sideband of the spectrum and a residual level of the carrier oscillation (pilot signal) is formed, see Fig. 2.

[0050] 8. The generated signals OM with the upper and lower sideband of the spectrum, respectively, from the output of the third adder 15 and the fourth adder 16 are fed to the first and second inputs of the resulting adder 21, at the output of which the resulting signal AM is obtained, containing information from two message sources, one of which is analog.

[0051] As an example, Fig. 2 shows the spectrum of the resulting AM signal |S AM (ƒ)|, formed in accordance with the claimed technical solution, in which the upper and lower side bands contain information from two different message sources.

[0052] The magnitude of the constant level signal generated by the unity level voltage generator 19 determines the residual level (magnitude) of the carrier oscillation in the resulting AM signal.

[0053] The separate operation of each of the blocks that make up the claimed device is known and presented in Verzunov M.V. Single-sideband modulation in radio communications. - M.: Voenizdat, 1972, - 296 p., Formation and generation of signals in military radio communication equipment. Part 1. Frequency synthesizers. Formation of radio signals: Textbook - St. Petersburg: VAS, 2022. 224 p.

Claims

A modulator of signals from two sources of messages contains a series-connected source of discrete samples of a low-frequency modulating signal, a first adder and a first multiplier, a series-connected second adder and a second multiplier, as well as a Hilbert converter, the input of which is connected to the output of the source of discrete samples of a low-frequency modulating signal, a generator for forming a voltage of a single level, the output of which is connected to the second inputs of the first and second adders, a phase shifter on , a high-frequency carrier oscillation generator, the output of which is connected to the second input of the first multiplier and the input of the phase shifter on , as well as a resulting adder, the output of which is the output of the modulator, characterized in that it additionally contains a first additional adder, a third multiplier and an inverter connected in series, wherein the first input of the additional adder is connected to the output of the Hilbert converter, and the second input is connected to the output of the unity-level voltage generator, and the second input of the third multiplier is connected to the output of the phase shifter on , an additional source of a low-frequency modulating signal, an analog-to-digital converter, an additional Hilbert converter, a second additional adder and a fourth multiplier connected in series, wherein the output of the analog-to-digital converter is also connected to the first input of the second adder, and the second input of the second additional adder is connected to the output of the unity-level voltage generator, as well as an additional phase shifter on , the output of which is connected to the second input of the fourth multiplier, and the device additionally contains a third adder, the first and second inputs of which are connected to the first multiplier and inverter, respectively, a fourth adder, the first and second inputs of which are connected to the fourth multiplier and the second multiplier, respectively, while the output of the high-frequency carrier oscillation generator is also simultaneously connected to the input of an additional phase shifter on and the second input of the second multiplier, while the outputs of the third and fourth adders are connected to the first and second inputs of the resulting adder, respectively.

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