CN113783819A - Signal modulation method, device and storage medium - Google Patents
Signal modulation method, device and storage medium Download PDFInfo
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Abstract
The invention discloses a signal modulation method, a device and a storage medium, wherein the method comprises the following steps: acquiring a digital signal to be modulated, and dividing the digital signal into a baseband signal and a non-baseband signal; modulating the baseband signal and the non-baseband signal by adopting different modulation methods respectively to obtain a first modulation signal corresponding to the baseband signal and a second modulation signal corresponding to the non-baseband signal; and superposing the first modulation signal and the second modulation signal to obtain a target modulation signal. The invention divides the multi-frequency digital signal into the baseband signal and the non-baseband signal to be modulated respectively, thereby realizing the modulation of the multi-frequency signal without carrying out Fourier transform on the digital signal. The problem that in the prior art, a multi-frequency signal modulation method (DMT) needs to perform Fourier transform on signals, so that the calculation cost is overlarge is effectively solved.
Description
Technical Field
The present invention relates to the field of signal processing, and in particular, to a signal modulation method, device and storage medium.
Background
In an optical fiber channel, since there is a problem of high frequency fading, which easily causes signal damage, in order to ensure effective transmission of signals, signals to be transmitted are modulated and then transmitted. At present, DMT modulation method is generally adopted for the modulation method of signals in multiple frequency bands, and has the best dispersion robustness and the best Bit Error Rate (BER) performance in a dispersion channel. However, since DMT implements frequency-domain modulation by fourier transform pairs, it requires storage, processing, and matrix operation of Digital signals, and relies heavily on Digital Signal Processing (DSP) circuitry. Since DMT relies heavily on DSP circuit implementation due to the fourier transform required, it is currently not suitable for use in optical interconnection scenarios within data centers and supercomputers. Therefore, there is a need to propose a new modulation technique of low complexity for optical interconnection scenarios within data centers and supercomputers, supporting optical fiber transmission of the order of 10 km.
In short, the modulation method (DMT) of the multi-frequency signal in the prior art needs fourier transform of the signal, and thus has a problem of excessive calculation overhead.
Thus, there is still a need for improvement and development of the prior art.
Disclosure of Invention
The present invention is directed to provide a signal modulation method, a signal modulation apparatus, and a storage medium, which are used to solve the problem of excessive computation overhead due to the fourier transform of the signal required in the multi-frequency signal modulation method (DMT) in the prior art.
The technical scheme adopted by the invention for solving the problems is as follows:
in a first aspect, an embodiment of the present invention provides a signal modulation method, where the method includes:
acquiring a digital signal to be modulated, and dividing the digital signal into a baseband signal and a non-baseband signal;
obtaining a first modulation signal according to the baseband signal, and obtaining a second modulation signal according to the non-baseband signal;
and superposing the first modulation signal and the second modulation signal to obtain a target modulation signal.
In one embodiment, the dividing the digital signal into a baseband signal and a non-baseband signal includes:
acquiring channel frequency response data corresponding to a target channel, wherein the target channel is a channel for transmitting the digital signal;
the digital signal is divided into a baseband signal and a non-baseband signal according to the channel frequency response data.
In one embodiment, the obtaining of the channel frequency response data corresponding to the target channel includes:
acquiring a test signal, and inputting the test signal into the target channel to obtain a response output signal;
determining channel impulse response data corresponding to the target channel according to the response output signal;
carrying out Fourier transform on the channel impulse response data to obtain the relation information of the amplitude of the digital signal changed by frequency;
and generating the channel frequency response data according to the relation information.
In one embodiment, said dividing said digital signal into a baseband signal and a non-baseband signal according to said channel frequency response data comprises:
determining a recessed point according to the channel frequency response data, wherein amplitude values corresponding to data points adjacent to the recessed point are all larger than amplitude values corresponding to the recessed point;
and dividing the digital signal into a baseband signal and a non-baseband signal according to the notch point.
In one embodiment, the pit points include sub-pit points, and the dividing the digital signal into a baseband signal and a non-baseband signal according to the pit points includes:
acquiring the frequencies corresponding to the plurality of sub-recessed points respectively, and taking the sub-recessed point with the minimum frequency as a target recessed point;
taking the frequency corresponding to the target depression point as a target frequency, taking a frequency band starting from 0 frequency to the target frequency in the digital signal as a first frequency band, and taking a frequency band larger than the target frequency in the digital signal as a second frequency band;
the baseband signal is generated from the first frequency band and the non-baseband signal is generated from the second frequency band.
In one embodiment, the obtaining a first modulation signal from the baseband signal and a second modulation signal from the non-baseband signal includes;
performing pulse amplitude modulation on the baseband signal to obtain the first modulation signal;
and carrying out non-carrier amplitude-phase modulation on the non-baseband signal to obtain the second modulation signal.
In one embodiment, the second modulation signal includes a plurality of sub-modulation signals, and the non-baseband signal is modulated without carrier amplitude and phase to obtain the second modulation signal, including:
dividing the non-baseband signal into a plurality of local signals according to the plurality of sub-pit points, wherein each local signal corresponds to a pair of adjacent sub-pit points in the plurality of sub-pit points;
determining a filtering center frequency corresponding to each local signal, wherein the filtering center frequency is a middle frequency of a pair of adjacent sub-pit points corresponding to each local signal;
and filtering each local signal according to the filtering center frequency corresponding to each local signal to obtain a plurality of sub-modulation signals.
In one embodiment, the superimposing the first modulation signal and the second modulation signal to obtain the target modulation signal includes:
and inputting the second modulation signal and the first modulation signal into an adder to obtain the target modulation signal.
In a second aspect, an embodiment of the present invention further provides a signal modulation apparatus, where the apparatus includes:
the device comprises a classification module, a modulation module and a demodulation module, wherein the classification module is used for acquiring a digital signal to be modulated and dividing the digital signal into a baseband signal and a non-baseband signal;
the modulation module is used for modulating the baseband signal and the non-baseband signal by adopting different modulation methods to obtain a first modulation signal corresponding to the baseband signal and a second modulation signal corresponding to the non-baseband signal;
and the superposition module is used for superposing the first modulation signal and the second modulation signal to obtain a target modulation signal.
In a third aspect, an embodiment of the present invention further provides a computer-readable storage medium, on which a plurality of instructions are stored, where the instructions are adapted to be loaded and executed by a processor to implement any of the steps of the signal modulation method described above.
The invention has the beneficial effects that: the embodiment of the invention divides a digital signal to be modulated into a baseband signal and a non-baseband signal by acquiring the digital signal; modulating the baseband signal and the non-baseband signal by adopting different modulation methods respectively to obtain a first modulation signal corresponding to the baseband signal and a second modulation signal corresponding to the non-baseband signal; and superposing the first modulation signal and the second modulation signal to obtain a target modulation signal. The invention divides the multi-frequency digital signal into the baseband signal and the non-baseband signal to be modulated respectively, thereby realizing the modulation of the multi-frequency signal without carrying out Fourier transform on the digital signal. The problem that in the prior art, a multi-frequency signal modulation method (DMT) needs to perform Fourier transform on signals, so that the calculation cost is overlarge is effectively solved.
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In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments described in the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.
Fig. 1 is a schematic flowchart of a signal modulation method according to an embodiment of the present invention.
Figure 2 is a diagram of channel impulse response data for a 5km transmission on the left side provided by an embodiment of the present invention.
Figure 3 is a graph of channel frequency response data for a 5km transmission on the left side provided by an embodiment of the present invention.
Fig. 4 is a schematic diagram of a joint modulation technique for PAM and CAP according to an embodiment of the present invention.
Fig. 5 is a frequency spectrum diagram of a signal that has been jointly modulated by PAM and CAP according to an embodiment of the present invention.
Fig. 6 is an eye diagram of a successfully demodulated signal provided by an embodiment of the present invention.
Fig. 7 is a connection diagram of internal modules of the signal modulation apparatus according to the embodiment of the present invention.
Fig. 8 is a functional block diagram of a terminal according to an embodiment of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention clearer and clearer, the present invention is further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
It should be noted that, if directional indications (such as up, down, left, right, front, and back … …) are involved in the embodiment of the present invention, the directional indications are only used to explain the relative positional relationship between the components, the movement situation, and the like in a specific posture (as shown in the drawing), and if the specific posture is changed, the directional indications are changed accordingly.
Data centers and supercomputer communication applications require short-range optical interconnect technology as support. Currently, the Intensity Modulation and Direct Detection (IMDD) technology is a key technology for short-distance optical interconnection due to its advantages of low cost, low power consumption, etc. In recent years, Pulse Amplitude Modulation (PAM) technology has been increasingly used in IMDD optical interconnection systems.
In an optical fiber channel, since there is a problem of high frequency fading, which easily causes signal damage, in order to ensure effective transmission of signals, signals to be transmitted are modulated and then transmitted. At present, DMT modulation method is generally adopted for the modulation method of signals in multiple frequency bands, and has the best dispersion robustness and the best Bit Error Rate (BER) performance in a dispersion channel. However, since DMT implements frequency-domain modulation by fourier transform pairs, it requires storage, processing, and matrix operation of Digital signals, and relies heavily on Digital Signal Processing (DSP) circuitry. Since DMT relies heavily on DSP circuit implementation due to the fourier transform required, it is currently not suitable for use in optical interconnection scenarios within data centers and supercomputers. Therefore, there is a need to propose a new modulation technique of low complexity for optical interconnection scenarios within data centers and supercomputers, supporting optical fiber transmission of the order of 10 km.
In short, the modulation method (DMT) of the multi-frequency signal in the prior art needs fourier transform of the signal, and thus has a problem of excessive calculation overhead.
In view of the above-mentioned drawbacks of the prior art, the present invention provides a signal modulation method, including: acquiring a digital signal to be modulated, and dividing the digital signal into a baseband signal and a non-baseband signal; modulating the baseband signal and the non-baseband signal by adopting different modulation methods respectively to obtain a first modulation signal corresponding to the baseband signal and a second modulation signal corresponding to the non-baseband signal; and superposing the first modulation signal and the second modulation signal to obtain a target modulation signal. The invention divides the multi-frequency digital signal into the baseband signal and the non-baseband signal to be modulated respectively, thereby realizing the modulation of the multi-frequency signal without carrying out Fourier transform on the digital signal. The problem that in the prior art, a multi-frequency signal modulation method (DMT) needs to perform Fourier transform on signals, so that the calculation cost is overlarge is effectively solved.
As shown in fig. 1, the method comprises the steps of:
step S100, obtaining a digital signal to be modulated, and dividing the digital signal into a baseband signal and a non-baseband signal.
Specifically, because the digital signals include signals of a low frequency band and signals of a high frequency band, and the signals of different frequency bands are difficult to modulate by using a uniform modulation method with low computation overhead, in order to implement modulation of such multi-frequency digital signals and reduce computation overhead required for modulation, in this embodiment, the digital signals need to be classified first, and then divided into baseband signals and non-baseband signals, and then the baseband signals and the non-baseband signals are modulated respectively, so as to complete the modulation process of the multi-frequency digital signals.
In one implementation, the dividing the digital signal into a baseband signal and a non-baseband signal specifically includes the following steps:
step S101, obtaining channel frequency response data corresponding to a target channel, wherein the target channel is a channel for transmitting the digital signal;
and step S102, dividing the digital signal into a baseband signal and a non-baseband signal according to the channel frequency response data.
Specifically, the channel may act on the passing signal (for example, weaken, change the frequency, and the like), the frequency band corresponding to the baseband signal in this embodiment is a low frequency band, and the low frequency band generally has no frequency attenuation; the frequency band corresponding to the non-baseband signal is a high frequency band, and the high frequency band may have frequency attenuation. Since different channel effects are different, in order to determine which part of the digital signal is the baseband signal and which part is the non-baseband signal, this embodiment needs to first acquire channel frequency response data of a target channel for transmitting the digital signal, where the channel frequency response data can reflect which part of the passed signal will be frequency attenuated by the target channel, and thus the digital signal can be divided into the baseband signal and the non-baseband signal according to the channel frequency response data.
In one implementation, the step S101 specifically includes the following steps:
step S1011, obtaining a test signal, inputting the test signal into the target channel, and obtaining a response output signal;
step S1012, determining channel impulse response data corresponding to the target channel according to the response output signal;
step S1013, Fourier transform is carried out on the channel impulse response data to obtain the relation information of the amplitude of the digital signal changed by frequency;
and step S1014, generating the channel frequency response data according to the relation information.
Specifically, the channel impulse response data is a response output signal at the output end of the channel when a unit impulse signal is input, and thus the channel impulse response may reflect a change occurring after the signal passes through the channel. In order to more intuitively see the change of the frequency of the signal after passing through the channel, the embodiment needs to perform fourier transform on the channel impulse response data, and because the fourier transform can convert the channel impulse response based on time domain description into frequency domain description, the relationship information of the amplitude of the digital signal subjected to frequency change can be obtained after the fourier transform, and the channel frequency response data can be obtained based on the relationship information.
For example, around a wavelength of 1550nm, transmitted using 5km of standard single mode fibre SSMF (typical dispersion value is 16ps/nm/km), the channel impulse response data is shown in figure 2 and the channel frequency response data is shown in figure 3. It can be seen that when a unit pulse is input, the pulse is severely distorted after 5km of SSMF transmission.
In one implementation, the step S102 specifically includes the following steps:
step S1021, determining a recessed point according to the channel frequency response data, wherein amplitude values corresponding to data points adjacent to the recessed point are all larger than amplitude values corresponding to the recessed point;
step S1022, dividing the digital signal into a baseband signal and a non-baseband signal according to the notch point.
Specifically, the notch points in this embodiment may reflect specific positions of frequency attenuation in the frequency band after the test signal passes through the target channel, and the notch points are represented as "valley bottom" positions in the channel frequency response data, so that the amplitude values of the notch points are all lower than the amplitude values corresponding to their adjacent data points. Since the notch point can reflect the specific position of the frequency attenuation in the frequency band after the test signal passes through the target channel, the baseband signal corresponds to the frequency band without frequency attenuation, and the non-baseband signal corresponds to the frequency band with frequency attenuation, the digital signal can be divided into the baseband signal and the non-baseband signal based on the notch point.
In one implementation manner, the recessed points include a plurality of sub-recessed points, and the step S1022 specifically includes the following steps:
step S10221, obtaining the frequencies corresponding to the sub-depression points respectively, and taking the sub-depression point with the minimum frequency as a target depression point;
step S10222, regarding a frequency corresponding to the target notch point as a target frequency, regarding a frequency band starting from 0 frequency to the target frequency in the digital signal as a first frequency band, and regarding a frequency band greater than the target frequency in the digital signal as a second frequency band;
step S10223 is to generate the baseband signal according to the first frequency band and generate the non-baseband signal according to the second frequency band.
Specifically, when a pit point includes several sub-pit points, it indicates that there are positions where a plurality of frequencies are attenuated. Because the first frequency attenuation position is the position where the frequency attenuation does not occur before the target notch point, the present embodiment obtains the baseband signal according to the frequency band before the target notch point, i.e. the first frequency band; and obtaining a non-baseband signal according to the frequency band positioned after the target concave point, namely the second frequency band.
For example, as shown in FIG. 3, in the range of 0GHz to 70GHz, there are 3 frequency notches exceeding 20dB, and three points are three sub-notch points.
In one implementation, the generating the non-baseband signal according to the second frequency band includes: taking a frequency band in a preset range with each sub-indentation point as the center in the second frequency band as an invalid frequency band; and generating the non-baseband signal according to the frequency bands except the invalid frequency band in the second frequency band.
Specifically, since the frequency attenuation corresponding to the frequency band within the preset range centered on each sub-pit point is severe, and signal transmission cannot be performed, the frequency bands are screened out, and then signal transmission is performed by using the remaining frequency bands.
For example, as shown in FIG. 3, in the range of 0GHz to 70GHz, there are 3 frequency notches exceeding 20dB, and three points are three sub-notch points. Since the three sub-pit points cannot perform effective transmission of signals, the three sub-pit points need to be avoided.
As shown in fig. 1, the method further comprises the steps of:
and step S200, obtaining a first modulation signal according to the baseband signal, and obtaining a second modulation signal according to the non-baseband signal.
Specifically, since there is no frequency fading in the baseband signal, but there is selective frequency fading in the non-baseband signal, it is necessary to separately perform signal modulation on the baseband signal and the non-baseband signal. In this embodiment, a modulation signal obtained by modulating a baseband signal is defined as a first modulation signal, and a modulation signal obtained by modulating a non-baseband signal is defined as a second modulation signal.
In one implementation, the step S200 specifically includes the following steps:
step S201, performing pulse amplitude modulation on the baseband signal to obtain the first modulation signal;
step S202, the non-baseband signal is modulated in a carrier-free amplitude-phase mode to obtain the second modulation signal.
In summary, since there is no frequency fading in the baseband signal, but there is selective frequency fading in the non-baseband signal, the present embodiment respectively modulates the baseband signal and the non-baseband signal by different modulation methods. Specifically, since Pulse Amplitude Modulation (PAM) has the advantage of low complexity, in order to ensure the transmission quality of the baseband signal, the present embodiment employs a method of pulse amplitude modulation to modulate the baseband signal to obtain the first modulation signal. Since the carrierless amplitude-phase modulation (CAP) can alleviate the signal damage caused by the optical fiber dispersion, in order to enable the non-baseband signal to be effectively transmitted in the target channel, the embodiment modulates the non-baseband signal by using the carrierless amplitude-phase modulation method to obtain the second modulation signal.
In one implementation, the second modulation signal includes a plurality of sub-modulation signals, and the step S202 specifically includes the following steps:
step S2021, dividing the non-baseband signal into a plurality of local signals according to the plurality of sub-pit points, wherein each local signal corresponds to a pair of adjacent sub-pit points in the plurality of sub-pit points;
step S2022, determining a filtering center frequency corresponding to each local signal, where the filtering center frequency is a middle frequency of a pair of adjacent sub-pit points corresponding to each local signal;
step S2023, filtering each local signal according to a filtering center frequency corresponding to each local signal, to obtain a plurality of sub-modulation signals.
Specifically, since the conventional carrierless amplitude-phase modulation technique cannot realize adaptive modulation of chromatic dispersion, the present embodiment improves the carrierless amplitude-phase modulation technique. First, it is required that the present embodiment divides the second frequency band into a plurality of sub-bands according to the determined plurality of sub-pit points, and then generates a local signal according to each sub-band, where each sub-band is a frequency band between a pair of adjacent sub-pit points, and thus each local signal corresponds to a pair of adjacent sub-pit points. Then, the intermediate frequency of a pair of adjacent sub-notch points is used as the filtering center frequency of the local signal corresponding to the pair of sub-notch points, and the local signal is filtered through the filtering center frequency to obtain the sub-modulation signal corresponding to the local signal. And after the filtering operation is finished on all local signals, a plurality of sub-modulation signals are obtained, so that the dispersion self-adaptive modulation is realized.
In short, PAM modulation of the baseband signal does not require filtering. And CAP modulation is performed on the non-baseband signal, which needs to be filtered by a filter to realize quadrature modulation. In the present embodiment, different filters are used for different local signals in the non-baseband signal, wherein the filtering center frequency of each filter is determined by the middle frequency of the local signal corresponding to the filter, so as to implement the band shifting of the signal and implement the self-adaptation of the dispersion channel. In one implementation, the filter employed in the present embodiment is an FIR filter.
As shown in fig. 1, the method further comprises the steps of:
and step S300, superposing the first modulation signal and the second modulation signal to obtain a target modulation signal.
In order to obtain a target modulation signal corresponding to the digital signal, the embodiment further needs to superimpose the first modulation signal and the second modulation signal, that is, aliasing the first modulation signal and the second modulation signal in the time domain.
In one implementation, the step S300 specifically includes the following steps:
step S301, inputting the second modulation signal and the first modulation signal into an adder to obtain the target modulation signal.
Specifically, the present embodiment is provided with an adder in advance, and by inputting the first modulation signal and the second modulation signal into the adder, a superimposed signal output by the adder based on the first modulation signal and the second modulation signal can be obtained, where the superimposed signal is the target modulation signal.
In one implementation, the method further comprises: and performing digital-to-analog conversion and electro-optical modulation on the target modulation signal and inputting the target modulation signal into the target channel.
In one implementation manner, this embodiment further provides a signal demodulation method, which is used to demodulate the target modulation signal:
step S1, receiving the target modulation signal, and dividing the target modulation signal into a first signal to be demodulated and a second signal to be demodulated, where the first signal to be demodulated corresponds to the baseband signal, and the second signal to be demodulated corresponds to the non-baseband signal;
step S2, inputting the first signal to be demodulated into a baseband filter to obtain a first demodulated signal;
step S3, dividing the second signal to be demodulated into a plurality of sub-signals to be demodulated, where the plurality of sub-signals to be demodulated correspond to the plurality of local signals one to one;
step S4, respectively inputting the sub-signals to be demodulated into different matched filters to obtain a plurality of second demodulated signals;
and step S5, determining information corresponding to the digital signal according to the first demodulation signal and a plurality of second demodulation signals.
Specifically, as shown in fig. 4, at a receiving end of a target channel, since a first modulation signal and a second modulation signal forming a target modulation signal are aliased in a time domain, in order to demodulate the target modulation signal, in this embodiment, the target modulation signal needs to be split into a first signal to be demodulated and a second signal to be demodulated, where the first signal to be demodulated corresponds to the baseband signal, and the second signal to be demodulated corresponds to the non-baseband signal, and then the first signal to be demodulated is demodulated by using a baseband filter. For the second signal to be demodulated, it needs to be split into sub-signals to be demodulated corresponding to each local signal. Then, for each sub-signal to be demodulated, a matched filter corresponding to the sub-signal to be demodulated is determined, and the demodulated sub-signal is demodulated according to the matched filter.
In order to verify the technical effect of the invention, the inventor makes the following tests: the frequency response degradation caused by dispersion is shown in fig. 3 for a 5km SSMF transmission scenario. And adjusting the bandwidth of the baseband PAM signal and the center frequency of the CAP signal according to the recessed frequency caused by dispersion, thereby realizing self-adaptive frequency modulation. The frequency spectrum diagram of the realized PAM and CAP combined modulation signal is shown in FIG. 5, and it can be seen that the signal spectrum presents a separation characteristic and perfectly avoids frequency depression caused by dispersion. By demodulating the CAP signal in the third frequency band, fig. 6 shows. It can be seen that the signal was successfully demodulated.
The invention has the advantages that:
1. a novel frequency domain modulation technology with low complexity is provided for an IMDD (inertial measurement data division multiple access) dispersion channel, can be applied to optical communication scenes of a data center and a super computer, and is used as a basic modulation technology.
2. One of the major characteristics of data center and beyond optical interconnects is high interconnect density, which places high demands on the cost and power consumption of the optical interconnects. The novel modulation technology provided perfectly conforms to the IMDD optical interconnection system framework, has better robustness on optical fiber dispersion, and can support optical interconnection of 10km level.
3. Compared with DMT, the method has lower complexity and is more suitable for optical communication scenes of data centers and super computers.
Based on the above embodiment, the present invention further provides a signal modulation apparatus, as shown in fig. 7, the apparatus includes:
the device comprises a classification module 01, a modulation module and a demodulation module, wherein the classification module is used for acquiring a digital signal to be modulated and dividing the digital signal into a baseband signal and a non-baseband signal;
a modulation module 02, configured to modulate the baseband signal and the non-baseband signal by using different modulation methods, respectively, to obtain a first modulation signal corresponding to the baseband signal and a second modulation signal corresponding to the non-baseband signal;
the superposition module 03 is configured to superpose the first modulation signal and the second modulation signal to obtain a target modulation signal.
Based on the above embodiments, the present invention further provides a terminal, and a schematic block diagram thereof may be as shown in fig. 8. The terminal comprises a processor, a memory, a network interface and a display screen which are connected through a system bus. Wherein the processor of the terminal is configured to provide computing and control capabilities. The memory of the terminal comprises a nonvolatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of an operating system and computer programs in the non-volatile storage medium. The network interface of the terminal is used for connecting and communicating with an external terminal through a network. The computer program is executed by a processor to implement a signal modulation method. The display screen of the terminal can be a liquid crystal display screen or an electronic ink display screen.
It will be understood by those skilled in the art that the block diagram of fig. 8 is a block diagram of only a portion of the structure associated with the inventive arrangements and is not intended to limit the terminals to which the inventive arrangements may be applied, and that a particular terminal may include more or less components than those shown, or may have some components combined, or may have a different arrangement of components.
In one implementation, one or more programs are stored in a memory of the terminal and configured to be executed by one or more processors include instructions for performing a signal modulation method.
It will be understood by those skilled in the art that all or part of the processes of the methods of the embodiments described above can be implemented by hardware instructions of a computer program, which can be stored in a non-volatile computer-readable storage medium, and when executed, can include the processes of the embodiments of the methods described above. Any reference to memory, storage, databases, or other media used in embodiments provided herein may include non-volatile and/or volatile memory. Non-volatile memory can include read-only memory (ROM), Programmable ROM (PROM), Electrically Programmable ROM (EPROM), Electrically Erasable Programmable ROM (EEPROM), or flash memory. Volatile memory can include Random Access Memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in a variety of forms such as Static RAM (SRAM), Dynamic RAM (DRAM), Synchronous DRAM (SDRAM), Double Data Rate SDRAM (DDRSDRAM), Enhanced SDRAM (ESDRAM), Synchronous Link DRAM (SLDRAM), Rambus Direct RAM (RDRAM), direct bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM).
In summary, the present invention discloses a signal modulation method, a signal modulation apparatus and a storage medium, wherein the method comprises: acquiring a digital signal to be modulated, and dividing the digital signal into a baseband signal and a non-baseband signal; modulating the baseband signal and the non-baseband signal by adopting different modulation methods respectively to obtain a first modulation signal corresponding to the baseband signal and a second modulation signal corresponding to the non-baseband signal; and superposing the first modulation signal and the second modulation signal to obtain a target modulation signal. The invention divides the multi-frequency digital signal into the baseband signal and the non-baseband signal to be modulated respectively, thereby realizing the modulation of the multi-frequency signal without carrying out Fourier transform on the digital signal. The problem that in the prior art, a multi-frequency signal modulation method (DMT) needs to perform Fourier transform on signals, so that the calculation cost is overlarge is effectively solved.
It is to be understood that the invention is not limited to the examples described above, but that modifications and variations may be effected thereto by those of ordinary skill in the art in light of the foregoing description, and that all such modifications and variations are intended to be within the scope of the invention as defined by the appended claims.
Claims (10)
1. A method of signal modulation, the method comprising:
acquiring a digital signal to be modulated, and dividing the digital signal into a baseband signal and a non-baseband signal;
obtaining a first modulation signal according to the baseband signal, and obtaining a second modulation signal according to the non-baseband signal;
and superposing the first modulation signal and the second modulation signal to obtain a target modulation signal.
2. The signal modulation method of claim 1, wherein the dividing the digital signal into a baseband signal and a non-baseband signal comprises:
acquiring channel frequency response data corresponding to a target channel, wherein the target channel is a channel for transmitting the digital signal;
the digital signal is divided into a baseband signal and a non-baseband signal according to the channel frequency response data.
3. The signal modulation method according to claim 2, wherein the obtaining of the channel frequency response data corresponding to the target channel comprises:
acquiring a test signal, and inputting the test signal into the target channel to obtain a response output signal;
determining channel impulse response data corresponding to the target channel according to the response output signal;
carrying out Fourier transform on the channel impulse response data to obtain the relation information of the amplitude of the digital signal changed by frequency;
and generating the channel frequency response data according to the relation information.
4. The signal modulation method of claim 2, wherein said dividing the digital signal into a baseband signal and a non-baseband signal according to the channel frequency response data comprises:
determining a recessed point according to the channel frequency response data, wherein amplitude values corresponding to data points adjacent to the recessed point are all larger than amplitude values corresponding to the recessed point;
and dividing the digital signal into a baseband signal and a non-baseband signal according to the notch point.
5. The signal modulation method of claim 4, wherein the notch points comprise sub-notch points, and wherein the dividing the digital signal into a baseband signal and a non-baseband signal according to the notch points comprises:
acquiring the frequencies corresponding to the plurality of sub-recessed points respectively, and taking the sub-recessed point with the minimum frequency as a target recessed point;
taking the frequency corresponding to the target depression point as a target frequency, taking a frequency band starting from 0 frequency to the target frequency in the digital signal as a first frequency band, and taking a frequency band larger than the target frequency in the digital signal as a second frequency band;
the baseband signal is generated from the first frequency band and the non-baseband signal is generated from the second frequency band.
6. The signal modulation method according to claim 5, wherein the obtaining a first modulation signal according to the baseband signal and a second modulation signal according to the non-baseband signal comprises;
performing pulse amplitude modulation on the baseband signal to obtain the first modulation signal;
and carrying out non-carrier amplitude-phase modulation on the non-baseband signal to obtain the second modulation signal.
7. The signal modulation method according to claim 6, wherein the second modulation signal comprises a plurality of sub-modulation signals, and the performing carrierless amplitude-phase modulation on the non-baseband signal to obtain the second modulation signal comprises:
dividing the non-baseband signal into a plurality of local signals according to the plurality of sub-pit points, wherein each local signal corresponds to a pair of adjacent sub-pit points in the plurality of sub-pit points;
determining a filtering center frequency corresponding to each local signal, wherein the filtering center frequency is a middle frequency of a pair of adjacent sub-pit points corresponding to each local signal;
and filtering each local signal according to the filtering center frequency corresponding to each local signal to obtain a plurality of sub-modulation signals.
8. The signal modulation method according to claim 1, wherein the superimposing the first modulation signal and the second modulation signal to obtain a target modulation signal comprises:
and inputting the second modulation signal and the first modulation signal into an adder to obtain the target modulation signal.
9. A signal modulation apparatus, characterized in that the apparatus comprises:
the device comprises a classification module, a modulation module and a demodulation module, wherein the classification module is used for acquiring a digital signal to be modulated and dividing the digital signal into a baseband signal and a non-baseband signal;
the modulation module is used for modulating the baseband signal and the non-baseband signal by adopting different modulation methods to obtain a first modulation signal corresponding to the baseband signal and a second modulation signal corresponding to the non-baseband signal;
and the superposition module is used for superposing the first modulation signal and the second modulation signal to obtain a target modulation signal.
10. A computer readable storage medium having stored thereon a plurality of instructions adapted to be loaded and executed by a processor to perform the steps of the signal modulation method according to any one of claims 1 to 8.
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