WO2024099015A1 - Signal demodulation system and method - Google Patents

Abstract

Provided in the present application are a signal demodulation system and method. The system comprises: a sending end and a receiving end, wherein the sending end processes a service signal on the basis of a single-tone signal, and then generates a first signal-sideband modulation (SSB) signal, which is superimposed with the single-tone signal; and the receiving end is used for processing the first SSB signal to generate the service signal. In the system provided in the present application, a single-tone signal is introduced into a sending end, such that aliasing between a self-mixing inference signal and a target signal can be avoided at a receiving end, thereby improving the system performance.

Description

A system and method for demodulating a signal

This application claims the priority of the Chinese patent application filed with the China Patent Office on November 7, 2022, with application number 202211385544.5 and application name “A System and Method for Demodulating Signals”, the entire contents of which are incorporated by reference in this application.

Technical Field

The present application relates to the field of optical communication technology, and more specifically, to a system and method for demodulating signals.

Background technique

In a communication system that uses single-sideband modulation (SSB) signals to improve spectrum efficiency, the receiving end needs to demodulate the received SSB signal, which usually includes coherent demodulation and carrier self-mixing demodulation. However, the receiving end of the coherent demodulation technology needs to introduce a local oscillator signal, and the local oscillators at both ends of the transmitter and receiver must be synchronized to obtain better communication performance. Self-mixing demodulation technology will introduce self-mixing interference signals, thereby affecting system performance. Therefore, how to avoid the low-frequency interference signal generated by self-mixing from overlapping with the target signal spectrum without adding a local oscillator signal at the receiving end is an urgent problem to be solved.

Summary of the invention

The present application provides a system and method for demodulating a signal, which can avoid aliasing between a self-mixing interference signal and a target signal, thereby improving system performance.

In a first aspect, an embodiment of the present application provides a system for demodulating a signal. The system includes: a transmitting end and a receiving end. The transmitting end processes a service signal based on a single-tone signal to generate a first single-sideband modulated SSB signal superimposed with the single-tone signal. The receiving end processes the first SSB signal to generate the service signal.

Based on the above scheme, the embodiment of the present application introduces a single-tone signal instead of a DC signal at the transmitting end, thereby avoiding the introduction of a local oscillator signal at the receiving end. At the same time, since the single-tone signal is superimposed on the SSB signal generated by the transmitting end, when the receiving end processes the SSB signal based on the superimposed single-tone signal, the spectrum separation of the target signal and the interference signal can be achieved, thereby achieving the purpose of improving system performance.

In combination with the first aspect, in a possible implementation of the first aspect, the transmitting end includes: an amplitude modulation module, a mixing module, an SSB signal generating module and a superposition module. The amplitude modulation module generates an amplitude modulation signal based on the service signal. The mixing module is used to mix the amplitude modulation signal with a carrier signal to generate a mixed signal. The SSB signal generating module generates an SSB signal based on the mixed signal. The superposition module is used to superimpose the SSB signal with a single tone signal to generate the first SSB signal.

In combination with the first aspect, in a possible implementation of the first aspect, the transmitting end includes: an amplitude modulation module, a mixing module, an SSB signal generating module and a superposition module. The amplitude modulation module generates an amplitude modulation signal based on the service signal. The superposition module is used to superimpose the amplitude modulation signal with the single tone signal to generate a superposition signal. The mixing module is used to mix the superposition signal with the carrier signal to generate a mixed signal. The SSB signal generating module generates the first SSB signal based on the mixing signal.

In combination with the first aspect, in a possible implementation of the first aspect, the receiving end includes: a self-mixing module, a filtering module, a sampling module and a demodulation module. The self-mixing module generates a self-mixing signal based on the first SSB signal. The filtering module is used to filter out the interference signal in the self-mixing signal to generate a second SSB signal. The sampling module is used to sample the second SSB signal to generate a sampling signal. The demodulation module demodulates the sampling signal to obtain the service signal.

Optionally, the sampling module is a bandpass sampling module.

In combination with the first aspect, in a possible implementation manner of the first aspect, the filtering module is a bandpass filter.

In combination with the first aspect, in a possible implementation manner of the first aspect, the filtering module includes a low-pass filter and a high-pass filter.

Based on the above scheme, the receiving end provided in the present application adopts a bandpass filter and a bandpass sampling module, which can achieve interference filtering and signal frequency shifting to the baseband frequency, avoiding the introduction of a local oscillator to achieve frequency relocation, thereby achieving the effect of reducing system power consumption.

In a second aspect, an embodiment of the present application provides a device for demodulating a signal. The device includes: a transceiver module and a processing module. The processing module processes a service signal based on a single-tone signal to generate a first single-sideband modulated SSB signal superimposed with the single-tone signal. The transceiver module is used to send the first single-sideband modulated SSB signal to a receiving device.

In combination with the second aspect, in a possible implementation manner of the second aspect, the processing module includes: an amplitude modulation module, a mixing module, SSB signal generating module and superposition module. The amplitude modulation module generates an amplitude modulation signal based on the service signal. The mixing module is used to mix the amplitude modulation signal with the carrier signal to generate a mixed signal. The SSB signal generating module generates an SSB signal based on the mixed signal. The superposition module is used to superimpose the SSB signal with a single tone signal to generate the first SSB signal.

In combination with the second aspect, in a possible implementation of the second aspect, the processing module includes: an amplitude modulation module, a mixing module, an SSB signal generating module and a superposition module. The amplitude modulation module generates an amplitude modulation signal based on the service signal. The superposition module is used to superimpose the amplitude modulation signal with the single tone signal to generate a superposition signal. The mixing module is used to mix the superposition signal with the carrier signal to generate a mixed signal. The SSB signal generating module generates the first SSB signal based on the mixing signal.

In a third aspect, an embodiment of the present application provides a device for demodulating a signal. The device includes: a transceiver module and a processing module. The transceiver module is used to receive a first SSB signal, where the first SSB signal is an SSB signal superimposed with a single tone signal. The processing module is used to process the first SSB signal to generate the service signal.

In combination with the third aspect, in a possible implementation of the third aspect, the processing module includes: a self-mixing module, a filtering module, a sampling module and a demodulation module. The self-mixing module generates a self-mixing signal based on the first SSB signal. The filtering module is used to filter out the interference signal in the self-mixing signal to generate a second SSB signal. The sampling module is used to sample the second SSB signal to generate a sampled signal. The demodulation module demodulates the sampled signal to obtain the service signal.

Optionally, the sampling module is a bandpass sampling module.

In combination with the third aspect, in a possible implementation manner of the third aspect, the filtering module is a bandpass filter.

In combination with the third aspect, in a possible implementation manner of the third aspect, the filtering module includes a low-pass filter and a high-pass filter.

In a fourth aspect, an embodiment of the present application provides a method for demodulating a signal. The method includes: processing a service signal based on a single-tone signal to generate a first single-sideband modulated SSB signal superimposed with the single-tone signal. Processing the first SSB signal to generate the service signal.

In combination with the fourth aspect, in a possible implementation of the fourth aspect, the processing of the service signal based on the single-tone signal to generate a first single-sideband modulated SSB signal superimposed with the single-tone signal includes: generating an amplitude modulation signal based on the service signal. Mixing the amplitude modulation signal with a carrier signal to generate a mixed signal. Generating an SSB signal based on the mixed signal. Superimposing the SSB signal with the single-tone signal to generate the first SSB signal.

In combination with the fourth aspect, in a possible implementation of the fourth aspect, the processing of the service signal based on the single-tone signal to generate a first single-sideband modulated SSB signal superimposed with the single-tone signal includes: generating an amplitude modulation signal based on the service signal. Superimposing the amplitude modulation signal with the single-tone signal to generate a superimposed signal. Mixing the superimposed signal with a carrier signal to generate a mixed signal. Generating the first SSB signal based on the mixed signal.

In combination with the fourth aspect, in a possible implementation of the fourth aspect, the processing of the first SSB signal to generate the service signal includes: generating a self-mixing signal based on the first SSB signal. Filtering out an interference signal in the self-mixing signal to generate a second SSB signal. Sampling the second SSB signal to generate a sampled signal. Demodulating the sampled signal to obtain the service signal.

In combination with the fourth aspect, in a possible implementation of the fourth aspect, filtering out the interference signal in the self-mixing signal to generate the second SSB signal includes: filtering out the interference signal in the self-mixing signal through a bandpass filter to generate the second SSB signal.

In combination with the fourth aspect, in a possible implementation of the fourth aspect, filtering out the interference signal in the self-mixing signal to generate the second SSB signal includes: filtering out the interference signal in the self-mixing signal by a low-pass filter and a high-pass filter to generate the second SSB signal.

In a fifth aspect, an embodiment of the present application provides a method for demodulating a signal. The method can be performed by a transmitting device or by a component of a transmitting device (such as a chip or a chip system, etc.), and the present application does not limit this. The method includes: processing a service signal based on a single-tone signal to generate a first single-sideband modulated SSB signal superimposed with the single-tone signal. Sending the first single-sideband modulated SSB signal to a receiving device.

In combination with the fifth aspect, in a possible implementation of the fifth aspect, the processing of the service signal based on the single-tone signal to generate a first single-sideband modulated SSB signal superimposed with the single-tone signal includes: generating an amplitude modulation signal based on the service signal. Mixing the amplitude modulation signal with a carrier signal to generate a mixed signal. Generating an SSB signal based on the mixed signal. Superimposing the SSB signal with the single-tone signal to generate the first SSB signal.

In combination with the fifth aspect, in a possible implementation of the fifth aspect, the processing of the service signal based on the single-tone signal to generate a first single-sideband modulated SSB signal superimposed with the single-tone signal includes: generating an amplitude modulation signal based on the service signal. Superimposing the amplitude modulation signal with the single-tone signal to generate a superimposed signal. Mixing the superimposed signal with a carrier signal to generate a mixed signal. Generating the first SSB signal based on the mixed signal.

In a sixth aspect, an embodiment of the present application provides a method for demodulating a signal. The method can be performed by a receiving device or by a component of a receiving device (such as a chip or a chip system, etc.), and the present application does not limit this. The method includes: receiving a first SSB signal, wherein the first SSB signal is an SSB signal superimposed with a single tone signal. The first SSB signal is processed to generate the service signal.

In combination with the sixth aspect, in a possible implementation of the sixth aspect, the processing the first SSB signal to generate the service signal includes: generating a self-mixing signal based on the first SSB signal. Filtering out an interference signal in the self-mixing signal to generate a second SSB signal. Sampling the second SSB signal to generate a sampled signal. Demodulating the sampled signal to obtain the service signal.

Optionally, the sampling module is a bandpass sampling module.

In combination with the sixth aspect, in a possible implementation of the sixth aspect, filtering out the interference signal in the self-mixing signal to generate a second SSB signal includes: filtering out the interference signal in the self-mixing signal through a bandpass filter to generate a second SSB signal.

In combination with the sixth aspect, in a possible implementation of the sixth aspect, filtering out the interference signal in the self-mixing signal to generate a second SSB signal includes: filtering out the interference signal in the self-mixing signal through a low-pass filter and a high-pass filter to generate a second SSB signal.

In a seventh aspect, an embodiment of the present application provides a system for demodulating signals, the system comprising: a memory and a processor. The memory is used to store instructions. The processor is used to call and execute the instructions from the memory, so that the system executes the method provided by the fourth aspect or any one of the above-mentioned implementations of the fourth aspect; or, the system executes the method provided by the fifth aspect or any one of the above-mentioned implementations of the fifth aspect; or, the system executes the method provided by the sixth aspect or any one of the above-mentioned implementations of the sixth aspect.

In an eighth aspect, an embodiment of the present application provides a system for demodulating signals. The communication system includes: a transmitting device and a receiving device, wherein the transmitting and receiving device and the receiving device have a communication connection, the transmitting device is used to execute the method provided in the fifth aspect and any one of the implementations of the fifth aspect, and the receiving device is used to execute the method provided in the sixth aspect and any one of the implementations of the sixth aspect.

In a ninth aspect, an embodiment of the present application provides a device for demodulating a signal. The device is used to execute the method provided in the fifth aspect. Specifically, the device for demodulating a signal may include a unit and/or module, such as a processing unit and an acquisition unit, for executing the method provided in the fifth aspect or any one of the above implementations of the fifth aspect.

In one implementation, the device for demodulating a signal is a transmitting device. The acquisition unit may be a transceiver, or an input/output interface; the processing unit may be at least one processor. Optionally, the transceiver may be a transceiver circuit. Optionally, the input/output interface may be an input/output circuit.

In another implementation, the device for demodulating the signal is a chip, a chip system or a circuit in a transmitting device. The acquisition unit may be an input/output interface, an interface circuit, an output circuit, an input circuit, a pin or a related circuit on the chip, the chip system or the circuit; the processing unit may be at least one processor, a processing circuit or a logic circuit.

In the tenth aspect, an embodiment of the present application provides a device for demodulating a signal, which is used to execute the method provided in the sixth aspect. Specifically, the device for demodulating a signal may include units and/or modules, such as a processing unit and an acquisition unit, for executing the method provided in the sixth aspect or any one of the above-mentioned implementations of the sixth aspect.

In one implementation, the device for demodulating a signal is a receiving device. The acquisition unit may be a transceiver, or an input/output interface; the processing unit may be at least one processor. Optionally, the transceiver may be a transceiver circuit. Optionally, the input/output interface may be an input/output circuit.

In another implementation, the device for demodulating the signal is a chip, a chip system or a circuit in a receiving device. The acquisition unit may be an input/output interface, an interface circuit, an output circuit, an input circuit, a pin or a related circuit on the chip, the chip system or the circuit; the processing unit may be at least one processor, a processing circuit or a logic circuit.

In the eleventh aspect, an embodiment of the present application provides a processor for executing the methods provided in the above aspects.

For the operations such as sending and acquiring/receiving involved in the processor, unless otherwise specified, or unless they conflict with their actual function or internal logic in the relevant description, they can be understood as operations such as processor output, reception, input, etc., or as sending and receiving operations performed by the radio frequency circuit and antenna, and this application does not limit this.

In a twelfth aspect, an embodiment of the present application provides a computer-readable storage medium. The computer-readable storage medium stores a program code for execution by a device, and the program code includes a method for executing the fourth aspect, the fifth aspect, or the sixth aspect and any one of the implementations of the fourth aspect, the fifth aspect, or the sixth aspect.

In a thirteenth aspect, the present application embodiment provides a computer program product comprising instructions. When the computer program product is executed on a computer When the computer is running on the computer, the computer executes the method provided by the fourth aspect, the fifth aspect, or the sixth aspect and any one of the implementations of the fourth aspect, the fifth aspect, or the sixth aspect.

In the fourteenth aspect, an embodiment of the present application provides a chip, which includes a processor and a communication interface. The processor reads instructions stored in a memory through the communication interface to execute the method provided by the fourth aspect, the fifth aspect, or the sixth aspect and any one of the implementation methods of the fourth aspect, the fifth aspect, or the sixth aspect.

Optionally, as an implementation method, the chip also includes a memory, in which a computer program or instructions are stored, and the processor is used to execute the computer program or instructions stored in the memory. When the computer program or instructions are executed, the processor is used to execute the method provided by the above-mentioned fourth aspect, fifth aspect, or sixth aspect and any one of the implementation methods of the fourth aspect, fifth aspect, or sixth aspect.

The beneficial effects brought about by the above-mentioned second to fourteenth aspects can be specifically referred to the description of the beneficial effects in the first aspect, and will not be repeated here.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a schematic diagram of an SSB modulator that generates an SSB signal using a filtering method.

FIG2 shows the amplitude-frequency response of the upper sideband filter and the lower sideband filter.

FIG. 3 shows a lower sideband SSB signal generated by a lower sideband filter and an upper sideband SSB signal generated by an upper sideband filter.

FIG. 4 shows a schematic diagram of an SSB modulator that generates an SSB signal using a phase shift method.

FIG5 shows a schematic flowchart of a method 500 for demodulating a signal provided in the present application.

FIG6 shows a schematic structural diagram of a first signal demodulation device 600 provided in an embodiment of the present application.

FIG. 7 shows a schematic diagram of a first signal spectrum provided in an embodiment of the present application.

FIG8 shows a schematic diagram of a second signal spectrum provided in an embodiment of the present application.

FIG. 9 shows a schematic diagram of a third signal spectrum provided in an embodiment of the present application.

FIG10 shows a schematic structural diagram of a second signal demodulation device 1000 provided in an embodiment of the present application.

FIG. 11 is a schematic diagram showing a fourth signal spectrum provided in an embodiment of the present application.

FIG. 12 shows a performance simulation schematic diagram provided in an embodiment of the present application.

FIG13 shows a schematic diagram of a fifth signal spectrum provided in an embodiment of the present application.

FIG. 14 shows a schematic structural diagram of a third signal demodulation device 1400 provided in an embodiment of the present application.

FIG. 15 shows a schematic structural diagram of a fourth signal demodulation device 1500 provided in an embodiment of the present application.

FIG. 16 shows a schematic structural diagram of a fifth signal demodulation device 1600 provided in an embodiment of the present application.

FIG. 17 shows a schematic structural diagram of a signal demodulation device 1700 provided in an embodiment of the present application.

Detailed ways

The technical solution in this application will be described below in conjunction with the accompanying drawings.

The technical solution of the present application can be applied to various optical communication systems, such as: plesiochronous digital hierarchy (PDH) optical communication system, synchronous digital hierarchy (SDH) optical communication system, dense wavelength division multiplexing (DWDM) optical communication system, all-optical network optical communication system, and other optical communication systems to be developed in the future. The embodiments of the present application are mainly explained by taking the short-distance optical communication system as an example. A short-distance optical communication system refers to an optical communication system with a total optical fiber length of less than 80 km.

The technical solution of the present application can also be applied to various communication systems, such as: long term evolution (LTE) system, LTE frequency division duplex (FDD) system, LTE time division duplex (TDD), universal mobile telecommunication system (UMTS), worldwide interoperability for microwave access (WiMAX) communication system, fifth generation (5G) system, new radio (NR) system, wireless-fidelity (WiFi) system, third generation partnership project (3GPP) related communication systems, and other communication systems (such as 6G system) or multiple communication fusion systems that may appear in the future.

To facilitate understanding of the embodiments of the present application, several terms involved in the present application are first briefly explained.

1. SSB technology: SSB technology is an important technology in analog modulation. When the signal is amplitude modulated, the signal spectrum will contain upper sideband and lower sideband, each of which contains all the information of the modulated signal. Therefore, only one sideband is needed to transmit all the information. Compared with amplitude modulation, double sideband modulation and residual sideband modulation, the SSB transmission bandwidth is only the modulation signal bandwidth, which effectively saves bandwidth. It not only saves resources, but also saves carrier transmission power. Therefore, it is widely used in shortwave radio broadcasting, carrier communication, data transmission and other fields. For example, carrier telephone, microwave multiplexing and ground-to-air telephone communication, and has been used in satellite-to-ground channels and mobile communication systems.

2. SSB signal: The SSB signal is a signal that only retains one sideband in the double-sideband signal. The current methods for generating SSB signals include filtering and phase shifting. Among them, the filtering method uses a sideband filter to filter out unwanted sidebands to generate an SSB signal. This method is based on the spectral characteristics of the signal, and removes the upper or lower sideband frequency components from the double-sideband signal to generate an SSB signal. FIG1 shows a schematic diagram of an SSB modulator that generates an SSB signal by filtering. Among them, the modulator 110 generates a double-sideband signal using an input signal and a carrier signal, and the double-sideband signal becomes an SSB signal after passing through the sideband filter hSSB 120. When the sideband filter hSSB is a lower sideband filter, FIG2 (a) shows the amplitude-frequency response of the lower sideband filter. When the sideband filter hSSB is an upper sideband filter, FIG2 (b) shows the amplitude-frequency response of the upper sideband filter. Corresponding to the lower sideband filter shown in FIG2 (a), FIG3 (a) shows the lower sideband SSB signal generated under the lower sideband filter. Corresponding to the upper sideband filter shown in (b) of Figure 2, (b) of Figure 3 shows the upper sideband SSB signal generated under the upper sideband filter. The essence of the phase shift method to generate SSB signals is to use the transfer function characteristics of the Hilbert filter to filter out one sideband. Figure 4 shows a schematic diagram of the principle of the phase shift method to generate SSB signals. Specifically, the service signal is first multiplied by the cosine carrier in the time domain to obtain the first double-variable sideband signal, and at the same time, each frequency component in the service signal is phase-shifted 90° through the Hilbert transform to obtain the transformed signal, and then the transformed signal is multiplied by the sine carrier in the time domain to obtain the second double-variable sideband signal. Then, adding the first double-wait signals will obtain the lower sideband SSB signal, and subtracting the first double-wait signals will obtain the upper sideband SSB signal.

Service signal 3. Coherent demodulation: Coherent demodulation is also called synchronous detection. The essence of demodulation is the same as modulation, both of which are spectrum shifting. Modulation is to shift the spectrum of the amplitude modulated signal to the position of the carrier spectrum, which can be achieved by multiplying it with the carrier through a multiplier. Demodulation is the reverse process of modulation, that is, to shift the spectrum of the modulated signal at the carrier position back to the original baseband position, which can also be achieved by multiplying it with the carrier through a multiplier.

In order to facilitate understanding of the embodiments of the present application, the following explanations are made.

First, the terms "first", "second", etc. and various numbers in the text descriptions or drawings of the embodiments of the present application shown below are only used for the convenience of description, and are not necessarily used to describe a specific order or sequence, and are not used to limit the scope of the embodiments of the present application. For example, in the embodiments of the present application, they are used to distinguish different signals.

Second, the terms "including" and "having" and any variations thereof in the embodiments of the present application shown below are intended to cover non-exclusive inclusions. For example, a process, method, system, product or apparatus comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or apparatuses.

Third, in the embodiments of the present application, words such as "exemplary" or "for example" are used to indicate examples, illustrations or descriptions, and the embodiments or designs described as "exemplary" or "for example" should not be interpreted as being more preferred or more advantageous than other embodiments or designs. The use of words such as "exemplary" or "for example" is intended to present related concepts in a specific way for easy understanding.

Fourth, in the embodiment of the present application, the carrier signal is also called a local oscillator signal.

In communication systems, the spectrum resources of channels are limited, so it is very important to improve spectrum efficiency. Compared with ordinary amplitude modulation and double-sideband modulation, the spectrum width occupied by SSB is half of the former, which improves the spectrum efficiency, so it is widely used in communication systems. At present, the method for the receiving end to realize SSB signal demodulation is mainly to adopt coherent demodulation or self-mixing demodulation with carrier. Among them, when the receiving end demodulates using coherent demodulation technology, the single-sideband signal sent by the transmitting end is first multiplied by a carrier with the same frequency and phase as the transmitting end, and then the signal is restored through a low-pass filter. This method introduces local oscillator signals at both ends of the system, which not only increases the cost of the system, but also increases the power consumption of the system. At the same time, it requires the synchronization of the local oscillators at both ends of the transmitting and receiving ends to obtain better communication performance. For self-mixing demodulation technology, since the DC signal is added when the transmitting end generates the single-sideband signal, the RF signal sent by the transmitting end carries the carrier signal. When the receiving end realizes demodulation through self-mixing, a self-mixing interference signal will be introduced, and there will be a phenomenon of overlapping of the interference signal and the target signal, thereby affecting the system performance.

In view of this, the present application provides a method for demodulating signals, so that the receiving device can avoid the spectrum aliasing phenomenon caused by self-mixing without having to introduce additional local oscillator signals, thereby achieving the purpose of saving costs and system power consumption while ensuring system performance.

The method for demodulating signals provided by the present application is described in detail below with reference to the accompanying drawings.

FIG5 shows a schematic flowchart of a method 500 for demodulating a signal provided by the present application. The method may be performed by a device for demodulating a signal provided by an embodiment of the present application or by a component (such as a chip or a chip system, etc.) of a device for demodulating a signal provided by an embodiment of the present application, and the present application does not limit this. The method 500 may include S510 and S520. The steps in the method 500 are described in detail below.

S510, process the service signal based on the single tone signal to generate a first SSB signal superimposed with the single tone signal.

Specifically, in the process of generating an SSB signal using a service signal, the transmitting end superimposes a single tone signal to generate a first SSB signal.

It should be understood that in the embodiment of the present application, the single-tone signal is a signal of a single frequency. The first SSB signal is an SSB signal superimposed with the frequency of the single-tone signal. The service signal is a signal carrying service data at a frequency of zero frequency, that is, in the embodiment of the present application, the frequency of the service signal is at zero frequency as an example for explanation.

When generating the first SSB signal, the transmitting end may first generate the SSB signal based on the service signal, and then superimpose the single tone signal to generate the first SSB signal. Alternatively, in the process of generating the SSB signal based on the service signal, the single tone signal is superimposed, so that the generated SSB signal is the first SSB signal, and the present application is applicable.

In addition, in an embodiment of the present application, the first SSB signal may be generated by a filtering method or a phase shift method, which is not limited in the present application. The process may refer to the relevant descriptions in the above-mentioned Figures 1 to 4 and will not be repeated here.

S520, process the first SSB signal to generate a service signal.

Specifically, after receiving the first SSB signal output by the transmitting end, the receiving end processes the first SSB signal accordingly and demodulates and recovers the baseband service signal.

Next, the demodulation method 500 provided in the present application is described in detail in conjunction with the device for demodulating a signal provided in an embodiment of the present application.

FIG6 shows a schematic diagram of the structure of the first signal demodulation device 600 provided in an embodiment of the present application, and the signal demodulation device 600 may also be referred to as a signal demodulation system 600. As shown in FIG6, the signal demodulation device 600 includes a transmitting end 610 and a receiving end 620, and the signal transmission between the transmitting end 610 and the receiving end 620 is transmitted through a channel. Among them, the transmitting end 610 includes an amplitude modulation module 611, a mixing module 612, an SSB signal generating module 613 and a superposition module 614. The receiving end 620 includes a self-mixing module 621, a filtering module 622, a sampling module 623 and a demodulation module 624.

Specifically, at the transmitting end, the amplitude modulation module 611 receives the service signal s0, modulates the amplitude of the service signal s0, generates an amplitude modulation signal s1, and outputs the generated amplitude modulation signal s1 to the mixing module 612, wherein the amplitude modulation signal is a double-sideband baseband signal with a center frequency of 0. The mixing module 612 mixes the amplitude modulation signal s1 with the carrier signal to generate a first mixing signal s2. This process can be regarded as moving the spectrum of the amplitude modulation signal s1 to the frequency of the carrier signal. The mixing module 612 outputs the generated first mixing signal s2 to the SSB signal generating module 613. The SSB signal generating module 613 uses sideband filtering or phase shifting method to implement single sideband modulation of the signal based on the received first mixing signal s2, generates an SSB signal s3, and outputs the SSB signal s3 to the superposition module 614. The superposition module 614 superimposes a single tone signal on the SSB signal s3 to generate a first SSB signal s4, and transmits the first SSB signal s4 to the channel for transmission. At the receiving end, after the self-mixing module 621 receives the first SSB signal y1 transmitted by the channel, it obtains the self-mixing signal y2 through self-mixing, that is, y ₂ =y ₁ ·y ₁ . At the same time, the self-mixing module 621 outputs the self-mixing signal y2 to the filtering module 622. After filtering out the interference signal in the self-mixing signal y2, the filtering module 622 outputs the second SSB signal y3 to the sampling module 623. The sampling module 623 samples the second SSB signal y3 to generate the sampling signal y4, that is, to achieve the frequency conversion of the second SSB signal y3, so that the generated sampling signal y4 contains the baseband signal of the 0 frequency. At the same time, the sampling module 623 outputs the sampling signal y4 to the demodulation module 624. The demodulation module 624 demodulates the sampling signal y4, and obtains the service signal y0 by demodulating the baseband signal in y4.

It should be noted that in actual scenarios, when the first SSB signal s4 sent by the transmitter reaches the receiving end through channel transmission, it is inevitable that power loss and the like will occur due to environmental and other factors, but such loss and the like will not affect the protection scope of this application. It should be understood that the first SSB signal s4 generated by the superposition module 614 and the first SSB signal y1 that reaches the self-mixing module 621 after channel transmission are not distinguished when performing principle analysis in the embodiment of this application, only to distinguish whether the signal is a transmitter signal or a receiver signal. In other words, the solution of this application is that the transmitter generates a first SSB signal, and the receiving end performs corresponding processing based on the first SSB signal.

Specifically, the principle of the method for modulating the signal provided by the present application is specifically described in conjunction with FIG. 7. As shown in FIG. 7, at the transmitting end, after the amplitude modulation signal s1 is mixed with the carrier signal, a first mixing signal s2 is generated. The mixing can be understood as the process of moving the spectrum of the amplitude modulation signal to the carrier frequency. The first mixing signal s2 generates an SSB signal s3 by filtering or phase shifting, and the first SSB signal spectrum generated after superimposing the single-tone signal is the s4 spectrum. The first SSB signal s4 is transmitted to the receiving end through the channel. For the receiving end, the receiving end first performs self-mixing on the received first SSB signal y1 to obtain a self-mixing signal y2. Among them, the self-mixing signal y2 contains a DC signal, a low-frequency interference signal, a target signal and a high-frequency interference signal. After filtering, the high-frequency interference signal, the low-frequency interference signal and the DC signal can be filtered out by the self-mixing signal y2 to generate a second SSB signal y3. Subsequently, after sampling, the SSB signal is moved to the baseband to obtain the spectrum y4. Finally, the service signal is obtained after demodulation and recovery.

Optionally, the filtering module 622 uses bandpass filtering to implement the filtering process of the spectrum y2, for example, the filtering module 622 can be a bandpass filter. Or the filtering can be a combination of high-pass filtering and low-pass filtering, that is, the filtering module 622 uses a combination of a low-pass filter and a high-pass filter to implement the filtering of the spectrum y2.

In addition, the sampling module 623 can adopt bandpass sampling to sample the spectrum y3 to generate the sampling signal y4.

For example, FIG8 and FIG9 show that the frequency of the single tone signal is f _c -Δf, the filtering module 622 is a bandpass filter, and the sampling module 623 is a spectrum diagram of bandpass sampling. Wherein, f _c is the frequency of the carrier signal, Δf ≥ B, or Δf ≤ -3B/2, and B is the bandwidth of the amplitude modulation signal s1. Specifically, FIG8 shows a spectrum diagram of the transmitting end and the receiving end when Δf ≥ B. As shown in FIG8, the frequency of the target signal contained in the self-mixing signal y2 is in the range of Δf to Δf + B/2. Therefore, a bandpass filter with a passband range satisfying Δf to Δf + B/2 can be used to filter the self-mixing signal y2. When Δf ≤ -3B/2, the spectrum diagram of the transmitting end and the receiving end is shown in FIG9, where the frequency of the mirror signal of the target signal contained in the self-mixing signal y2 is in the range of -Δf-B/2 to -Δf. At this time, the passband range of the bandpass filter satisfies -Δf-B/2 to -Δf. In addition, FIG8 and FIG9 both show the signal spectra of bandpass sampling with bandpass sampling rates _fs of |Δf| and |Δf/n|, where _fs satisfies _fs≥B , and _nfs ＝|Δf|, and n is an integer ≥1.

It should be noted that the frequency of the single-tone signal shown in Figures 8 and 9 and the sampling rate of the bandpass sampling are exemplary descriptions and do not limit the scope of protection of the present application. For example, Δf may be less than B, or Δf is greater than -3B/2, that is, Δf does not meet the requirement Δf≥B, or Δf≤-3B/2. At this time, the spectrum of the target signal and the low-frequency interference signal will be aliased, resulting in a decrease in system performance. It should be understood that in practical applications, Δf can be less than B, or Δf is greater than -3B/2, within the allowed range, depending on the application scenario. It should also be understood that the closer Δf is to 0, the more serious the aliasing of the spectrum of the target signal and the low-frequency interference signal.

Next, according to the different forms of the filter module 622, the device 600 for demodulating signals provided in the present application is specifically described. When the filter module 622 is a bandpass filter, FIG. 10 shows a schematic diagram of the structure of the device 1000 for demodulating signals provided in an embodiment of the present application, and the device 1000 for demodulating signals may also be referred to as a system 1000 for demodulating signals. Among them, the device 1000 includes a transmitting end 1010 and a receiving end 1020, wherein the transmitting end 1010 includes an amplitude modulation module 1011, a mixer 1012, a sideband filter or a phase shift SSB modulator 1013, and a superposition module 1014. The receiving end 1020 includes a self-mixing module 1021, a bandpass filter 1022, a bandpass sampling module 1023, and a demodulation module 1024. Specifically, the amplitude modulated signal s1 is mixed with the carrier signal through the mixer, the signal is modulated to the carrier, and the mixed signal s2 is output. The mixing signal s2 is modulated by a sideband filter or a phase-shift SSB modulator to obtain an SSB signal s3. A single-tone signal is introduced into the SSB signal s3 to obtain the first SSB signal s4. The self-mixing module performs self-mixing on the first SSB signal y1 received from the channel and outputs a self-mixing signal y2. The bandpass filter removes the high-frequency interference signal, low-frequency interference signal and direct current in the self-mixing signal y2, and outputs the second SSB signal y3. The second SSB signal y3 is bandpass sampled to output a sampling signal y4. After obtaining the baseband signal in the sampling signal y4, it is demodulated and restored to the service signal y0.

In an achievable manner, when the frequency of the single-tone signal is f _c -B, that is, Δf=B, FIG. 11 shows a signal spectrum diagram output by each module, wherein f _c is the carrier frequency and B is the bandwidth of the amplitude modulation signal. Since the first SSB signal y1 carries a single-tone signal with a frequency of f _c -B, the self-mixing signal y2 contains a target signal, a high-frequency interference signal, a direct current, and a low-frequency interference signal with a frequency of B to 3B/2, and therefore, the passband range of the bandpass filter 1022 needs to satisfy B to 3B/2. At this time, the bandpass sampling module 1023 performs bandpass sampling on the second SSB signal y3 with a frequency of B to 3B/2, and the sampling rate f _s =B. FIG. 12 shows a schematic diagram of system performance simulation when the frequency of the single-tone signal is f _c -B. As shown in FIG. 12, when the coherent demodulation method is used for signal demodulation, if the local oscillators of the receiving end and the transmitting end are not synchronized, the performance of the system will be sharply degraded. That is, the performance of the system is closely related to the degree of synchronization of the local oscillators of the receiving end and the transmitting end. Therefore, this method has high requirements for the synchronization of the local oscillators of the receiving end and the transmitting end. In addition, the performance of the system using the demodulation method provided by the present application is better than that of the self-mixing demodulation method.

In another achievable manner, when the frequency of the single-tone signal is f _c +3B/2, that is, Δf = -3B/2, FIG13 shows the signal spectrum diagram output by each module, and similarly, f _c is the carrier frequency, and B is the bandwidth of the amplitude modulation signal. Since the first SSB signal y1 carries a single-tone signal with a frequency of f _c +3B/2, the self-mixing signal y2 contains the image of the target signal with a frequency of B to 3B/2, a high-frequency interference signal, a direct current, and a low-frequency interference signal, therefore, the passband range of the bandpass filter 1022 needs to satisfy B to 3B/2. At this time, the bandpass sampling module 1023 performs bandpass sampling on the second SSB signal y3 with a frequency of B to 3B/2, and the sampling rate f _s = 3B/2.

When the filter module 622 is a low-pass filter and a high-pass filter, FIG14 shows a schematic diagram of the structure of a demodulation signal device 1400 provided in an embodiment of the present application, and the demodulation signal device 1400 may also be referred to as a demodulation signal system 1400. Among them, the device 1000 includes a transmitting end 1410 and a receiving end 1420. Among them, the transmitting end 1410 includes an amplitude modulation module 1411, a mixer 1412, a sideband filter or a phase shift SSB modulator 1413 and a superposition module 1414. The receiving end 1420 includes a self-mixing module 1421, a low-pass filter 1422, a high-pass filter 1423, a bandpass sampling module 1424 and a demodulation module 1425. Specifically, the amplitude modulated signal s1 is mixed with the carrier signal through the mixer, the signal is modulated to the carrier, and the mixed signal s2 is output. The mixed signal s2 is modulated by a single sideband of a sideband filter or a phase shift SSB modulator to obtain an SSB signal s3. A single tone signal is introduced into the SSB signal s3 to obtain the first SSB signal s4. The self-mixing module performs self-mixing on the first SSB signal y1 received from the channel and outputs a self-mixing signal y2. The low-pass filter 1422 filters out the high-frequency interference signal in the self-mixing signal y2 and outputs a low-pass filter signal y5. The low-pass filter signal y5 then passes through the high-pass filter 1423, and the low-frequency interference signal and direct current in the low-pass filter signal y5 are filtered out to output the second SSB signal y3. The second SSB signal y3 is band-pass sampled to output a sampling signal y4. After the baseband signal is obtained in the sampling signal y4, it is demodulated and restored to the service signal.

In an achievable manner, when the frequency of the single-tone signal is _fc -Δf, and Δf≥B ( _fc is the carrier frequency, and B is the bandwidth of the amplitude modulation signal), since the first SSB signal y1 carries a single-tone signal with a frequency of _fc -Δf, the self-mixing signal y2 includes a target signal, a high-frequency interference signal, a direct current, and a low-frequency interference signal with a frequency between Δf and Δf+B/2. If the passband range of the low-pass filter 1422 satisfies 0 to Δf+B/2, the output low-pass filtered signal y5 includes a target signal, a direct current signal, and a low-frequency interference signal with a frequency between Δf and Δf+B/2. Subsequently, a high-pass filter with a passband range of Δf to ∞ is used to filter out the direct current signal and the low-frequency interference signal in the low-pass filtered signal y5 to obtain a second SSB signal y3. The bandpass sampling module 1424 performs bandpass sampling on the second SSB signal y3 at a frequency between Δf and Δf+B/2. It should be understood that the bandpass sampling rate _fs needs to satisfy the requirements of _fs≥B , and _nfs ＝|Δf|, where n is an integer≥1.

In another achievable manner, when the frequency of the single-tone signal is f _c -Δf, and Δf ≤ -3B/2 (f _c is the carrier frequency, and B is the bandwidth of the amplitude modulation signal), since the first SSB signal y1 carries a single-tone signal with a frequency of f _c -Δf, the self-mixing signal y2 contains the image of the target signal with a frequency between -Δf-B/2 and -Δf, a high-frequency interference signal, a direct current, and a low-frequency interference signal. Therefore, the passband range of the bandpass filter 1022 needs to satisfy B to 3B/2. If the passband range of the low-pass filter 1422 satisfies 0 to -Δf, the output low-pass filter signal y5 contains the image of the target signal with a frequency between -Δf-B/2 and -Δf, a direct current signal, and a low-frequency interference signal. Subsequently, a high-pass filter with a passband range of -Δf-B/2 to ∞ is used to filter out the direct current signal and the low-frequency interference signal in the low-pass filter signal y5 to obtain a second SSB signal y3. The bandpass sampling module 1424 performs bandpass sampling on the second SSB signal y3 at a frequency of -Δf-B/2 to -Δf. It should be understood that the bandpass sampling rate _fs needs to satisfy the requirements of _fs≥B , and _nfs ＝|Δf|, where n is an integer≥1.

When the filter module 622 is a low-pass filter and a high-pass filter, FIG15 shows a schematic diagram of the structure of a demodulation signal device 1500 provided in an embodiment of the present application, and the demodulation signal device 1500 may also be referred to as a demodulation signal system 1500. The device 1000 includes an amplitude modulation module 1511, a mixer 1512, a sideband filter or a phase shift SSB modulator 1513, a superposition module 1514, a self-mixing module 1521, a high-pass filter 1522, a low-pass filter 1523, a bandpass sampling module 1524, and a demodulation module 1525. Compared with the signal demodulation device 1400, the signal demodulation device 1500 generates a high-pass filter signal y6 by passing the self-mixing signal y2 output by the self-mixing module 1521 through the high-pass filter 1522, and then generates a second SSB signal y3 by passing the high-pass filter signal y6 through the low-pass filter 1523, which can be regarded as exchanging the order of the low-pass filter 1422 and the high-pass filter 1423 in the signal demodulation device 1400. It should be understood that the functions of other modules in FIG. 15 can refer to the description of the corresponding modules in FIG. 14 above, and will not be repeated here.

FIG16 shows a schematic diagram of the structure of a demodulation signal device 1600 provided in an embodiment of the present application, and the demodulation signal device 1600 may also be referred to as a demodulation signal system 1600. As shown in FIG16, the demodulation signal device 1600 includes a transmitting end 1610 and a receiving end 1620, and the signal transmission between the transmitting end 1610 and the receiving end 1620 is transmitted through a channel. Among them, the transmitting end 1610 includes an amplitude modulation module 1611, a superposition module 1612, a mixing module 1613, and an SSB signal generating module 1614. The receiving end 1620 includes a self-mixing module 1621, a filtering module 1622, a sampling module 1623, and a demodulation module 1624.

Specifically, at the transmitting end, the amplitude modulation module 1611 receives the service signal s0, modulates the amplitude of the service signal s0, generates an amplitude modulation signal s1, and outputs the generated amplitude modulation signal s1 to the superposition module 1612. The superposition module 1612 superimposes a single-tone signal on the amplitude modulation signal s1 to generate a superposition signal s5, and outputs the superposition signal s5 to the mixing module 1613. The mixing module 1613 moves the spectrum of the superposition signal s5 to the frequency of the carrier signal to generate a second mixing signal s6. The mixing module 1613 outputs the generated second mixing signal s6 to the SSB signal generating module 1614. The SSB signal generating module 1614 uses sideband filtering or phase shifting method to implement single sideband modulation of the signal based on the received second mixing signal s6, generates a first SSB signal s4, and transmits the first SSB signal s4 to the channel for transmission. At the receiving end, after the self-mixing module 1621 receives the first SSB signal y1 transmitted by the channel, it obtains the self-mixing signal y2 through self-mixing, that is, y ₂ =y ₁ ·y ₁ . At the same time, the self-mixing module 1621 outputs the self-mixing signal y2 to the filtering module 1622. After filtering out the interference signal in the self-mixing signal y2, the filtering module 1622 outputs the second SSB signal y3 to the sampling module 1623. The sampling module 1623 samples the second SSB signal y3 to generate the sampling signal y4, that is, to achieve the frequency conversion of the second SSB signal y3. At the same time, the sampling module 1623 outputs the sampling signal y4 to the demodulation module 1624. The demodulation module 1624 demodulates the sampling signal y4 to obtain the service signal y0.

Similarly, the first SSB signal s4 generated by the superposition module 1614 and the first SSB signal y1 reaching the self-mixing module 1621 after channel transmission are not distinguished in the embodiment of the present application, only to distinguish whether the signal is a transmitting end signal or a receiving end signal.

Compared with the apparatus 600 for demodulating a signal shown in FIG6 , the apparatus 1600 for demodulating a signal can be regarded as changing the order of modules in the transmitting end 610 of the apparatus 600 for demodulating a signal. It should be understood that the condition that the superposition module 1612 can be placed before the SSB signal generating module 1614 is that the frequency of the single tone signal superimposed by the superposition module 1612 should be greater than the center frequency of the first SSB signal s4. In other words, the frequency of the single tone signal superimposed by the superposition module 1612 will not be removed in the SSB signal generating module 1614.

In addition, the device 1600 for demodulating signals can also have different variations according to different forms of the filtering module 1622 (i.e., a bandpass filter or a combination of a high-pass filter and a low-pass filter). Please refer to the relevant descriptions in Figure 10, Figure 14 and Figure 15 above, and no further details will be given here.

FIG17 is a schematic block diagram of a signal demodulation device 1700 provided in an embodiment of the present application. The signal demodulation device 1700 may also be referred to as a signal demodulation system 1700. The device 1700 includes a receiving module 1701, which may be used to implement the corresponding receiving function of the transmitting end or the receiving end in the above embodiment. The receiving module 1701 may also be referred to as a receiving unit.

The device 1700 also includes a processing module 1702, which can be used to implement the corresponding processing functions of the sending end or the receiving end in the above embodiments.

The device 1700 further includes a sending module 1703 , which can be used to implement the corresponding sending function of the sending end or the receiving end in the above embodiments. The sending module 1703 can also be called a sending unit.

Optionally, the device 1700 also includes a storage unit, which can be used to store instructions and/or data, and the processing unit 1702 can read the instructions and/or data in the storage unit so that the device implements the actions of the sending end or the receiving end in the aforementioned method embodiment.

The terms "component", "module", "system", etc. used in this specification are used to represent computer-related entities, hardware, firmware, a combination of hardware and software, software, or software in execution. For example, a component can be, but is not limited to, a process running on a processor, a processor, an object, an executable file, an execution thread, a program and/or a computer. By way of illustration, both applications running on a computing device and a computing device can be components. One or more components may reside in a process and/or an execution thread, and a component may be located on a computer and/or distributed between two or more computers. In addition, these components may be executed from various computer-readable media having various data structures stored thereon. Components may, for example, communicate through local and/or remote processes according to signals having one or more data packets (e.g., data from two components interacting with another component between a local system, a distributed system and/or a network, such as the Internet interacting with other systems through signals).

Those of ordinary skill in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different devices to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned equipment embodiments and will not be repeated here.

In the several embodiments provided in the present application, it should be understood that the disclosed systems, devices and equipment can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application can be essentially or partly embodied in the form of a software product that contributes to the prior art. The computer software product is stored in a storage medium and includes several instructions for a computer device (which can be a personal computer, server, or network device, etc.) to execute all or part of the steps of the device described in each embodiment of the present application. The aforementioned storage media include: U disk, mobile hard disk, read-only memory (ROM), random access memory (RAM), disk or optical disk, and other media that can store program codes.

The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims (15)

A system for demodulating signals, characterized in that the system comprises: a transmitting end and a receiving end, The transmitting end processes the service signal based on the single-tone signal to generate a first single-sideband modulated SSB signal superimposed with the single-tone signal; The receiving end processes the first SSB signal to generate the service signal. The system according to claim 1, characterized in that the transmitting end comprises: an amplitude modulation module, a mixing module, an SSB signal generating module and a superposition module, The amplitude modulation module generates an amplitude modulation signal based on the service signal; The mixing module is used to mix the amplitude modulated signal with a carrier signal to generate a mixed signal; The SSB signal generating module generates an SSB signal based on the mixing signal; The superposition module is used to superimpose the SSB signal with a single-tone signal to generate the first SSB signal. The system according to claim 1, characterized in that the transmitting end comprises: an amplitude modulation module, a mixing module, an SSB signal generating module and a superposition module, The amplitude modulation module generates an amplitude modulation signal based on the service signal; The superposition module is used to superimpose the amplitude modulation signal and the single tone signal to generate a superposition signal; The mixing module is used to mix the superimposed signal with a carrier signal to generate a mixed signal; The SSB signal generating module generates the first SSB signal based on the mixing signal. The system according to any one of claims 1 to 3, characterized in that the receiving end comprises: a self-mixing module, a filtering module, a sampling module and a demodulation module, The self-mixing module generates a self-mixing signal based on the first SSB signal; The filtering module is used to filter out the interference signal in the self-mixing signal to generate a second SSB signal; The sampling module is used to sample the second SSB signal to generate a sampling signal; The demodulation module demodulates the sampled signal to obtain the service signal. The system according to claim 4, characterized in that the filtering module is a bandpass filter. The system according to claim 4, characterized in that the filtering module includes a low-pass filter and a high-pass filter. A method for demodulating a signal, comprising: Processing the service signal based on the single-tone signal to generate a first single-sideband modulated SSB signal superimposed with the single-tone signal; The first SSB signal is processed to generate the service signal. The method according to claim 7 is characterized in that the processing of the service signal based on the single-tone signal to generate a first single-sideband modulated SSB signal superimposed with the single-tone signal comprises: generating an amplitude modulated signal based on the service signal; Mixing the amplitude modulated signal with a carrier signal to generate a mixed signal; generating an SSB signal based on the mixing signal; The SSB signal is superimposed on a single tone signal to generate the first SSB signal. The method according to claim 7 is characterized in that the processing of the service signal based on the single-tone signal to generate a first single-sideband modulated SSB signal superimposed with the single-tone signal comprises: generating an amplitude modulated signal based on the service signal; Superimposing the amplitude modulated signal and the single tone signal to generate a superimposed signal; Mixing the superimposed signal with a carrier signal to generate a mixed signal; The first SSB signal is generated based on the mixing signal. The method according to any one of claims 7 to 9, characterized in that the processing of the first SSB signal to generate the service signal comprises: generating a self-mixing signal based on the first SSB signal; Filtering out interference signals in the self-mixing signal to generate a second SSB signal; Sampling the second SSB signal to generate a sampling signal; The sampled signal is demodulated to obtain the service signal. The method according to claim 10 is characterized in that filtering out the interference signal in the self-mixing signal to generate the second SSB signal comprises: filtering out the interference signal in the self-mixing signal by a bandpass filter to generate the second SSB signal. The method according to claim 10 is characterized in that filtering out the interference signal in the self-mixing signal to generate the second SSB signal includes: filtering out the interference signal in the self-mixing signal by a low-pass filter and a high-pass filter to generate the second SSB signal. A device for demodulating a signal, comprising: The device comprises a processor, wherein the processor is configured to execute a computer program or instruction stored in a memory, so that the device performs the method according to any one of claims 7 to 12. The device according to claim 13, characterized in that the device further comprises the memory and/or the communication interface, wherein the communication interface is coupled to the processor, The communication interface is used to input and/or output signals. A computer-readable storage medium, characterized in that a computer program is stored on the computer-readable storage medium, and when the computer program is run on a computer, the computer is caused to execute the method as described in any one of claims 7 to 12.