CN116778697A - Digital analog signal mixed transmission method - Google Patents
Digital analog signal mixed transmission method Download PDFInfo
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- CN116778697A CN116778697A CN202310013608.7A CN202310013608A CN116778697A CN 116778697 A CN116778697 A CN 116778697A CN 202310013608 A CN202310013608 A CN 202310013608A CN 116778697 A CN116778697 A CN 116778697A
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Classifications
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- G—PHYSICS
- G08—SIGNALLING
- G08C—TRANSMISSION SYSTEMS FOR MEASURED VALUES, CONTROL OR SIMILAR SIGNALS
- G08C17/00—Arrangements for transmitting signals characterised by the use of a wireless electrical link
- G08C17/02—Arrangements for transmitting signals characterised by the use of a wireless electrical link using a radio link
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- G—PHYSICS
- G08—SIGNALLING
- G08C—TRANSMISSION SYSTEMS FOR MEASURED VALUES, CONTROL OR SIMILAR SIGNALS
- G08C15/00—Arrangements characterised by the use of multiplexing for the transmission of a plurality of signals over a common path
- G08C15/02—Arrangements characterised by the use of multiplexing for the transmission of a plurality of signals over a common path simultaneously, i.e. using frequency division
- G08C15/04—Arrangements characterised by the use of multiplexing for the transmission of a plurality of signals over a common path simultaneously, i.e. using frequency division the signals being modulated on carrier frequencies
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
- H04B1/38—Transceivers, i.e. devices in which transmitter and receiver form a structural unit and in which at least one part is used for functions of transmitting and receiving
- H04B1/40—Circuits
Abstract
The application provides a digital analog signal mixed transmission method, which comprises the following steps that S1, a digital signal and an analog signal are respectively transmitted to a frequency mixing module, and the frequency mixing module combines the digital signal and the analog signal into a modulation signal; s2, amplifying the modulated signal to a preset intensity and then sending the amplified modulated signal to a receiving end; s3, the receiving end receives the modulation signal, and then sends the modulation signal to a tuning amplifier to amplify a high-frequency signal and sends the high-frequency signal to an envelope detector; s4, demodulating the signals by an envelope detector, limiting and obtaining envelope contents to be processed in the demodulation process, wherein the signals carried by the envelope contents are analog signals in the step S1, and filtering the signals by the envelope detector according to preset amplitude to identify digital signals. Compared with the prior art, the application adopts the principles of simultaneous transmission of digital signals and voice signals, analog modulation and demodulation and digital modulation and demodulation to realize the first modulation and then mixed transmission.
Description
Technical Field
The application relates to the field of communication methods, in particular to a digital-analog signal mixed transmission method.
Background
Radio communication technology has evolved as a communication technology from the end of the 19 th century to today, which has evolved quite well. FM transceiver devices are widely used in civilian and military applications as a product of this technology. Although the popularization of the devices such as the internet, mobile phones and televisions is in the market of FM transceiver devices such as FM radios and interphones, a plurality of development spaces still exist in the fields such as aviation communication and natural disasters.
With the development and progress of society, human activities are increasingly dependent on services provided by wireless communication technology, so that the wireless communication technology is rapid and convenient, and can move, wherein wireless transmission of voice signals is a basic requirement, and is receiving high attention of people, and rapid development is achieved.
Disclosure of Invention
The application aims to overcome the defects of the prior art and provides a digital-analog signal mixed transmission method. The wireless receiving and transmitting system has a long transmission distance, can perform wireless receiving and transmitting on voice signals with high quality, and has a high frequency spectrum utilization rate.
The technical proposal provided is a digital analog signal mixed transmission method, which is characterized by comprising the following steps,
s1, respectively transmitting a digital signal and an analog signal to a frequency mixing module, wherein the frequency mixing module combines the digital signal and the analog signal into a modulation signal, and two different frequency heights are respectively set for different physical quantities of the digital signal;
s2, amplifying the modulated signal to a preset intensity and then sending the amplified modulated signal to a receiving end;
s3, the receiving end receives the modulation signal, and then sends the modulation signal to a tuning amplifier to amplify a high-frequency signal and sends the high-frequency signal to an envelope detector;
s4, demodulating the signals by an envelope detector, limiting and obtaining envelope contents to be processed in the demodulation process, wherein the signals carried by the envelope contents are analog signals in the step S1, the analog signals are output to a first follower, the first follower outputs the envelope contents, namely, the analog signals in the step S1 are obtained at a receiving end, the envelope detector simultaneously inputs the signals into a high-frequency band-pass filter and a low-frequency high-pass filter, and the high-frequency band-pass filter and the low-frequency high-pass filter respectively pick up different frequencies and convert the different frequencies into corresponding physical quantities and then output digital signals again according to a preset sequence combination.
Further, the voice signal is recorded and then is a first analog signal in a carrier wave form, the digital signal is modulated into a second analog signal through binary digital frequency, and the first analog signal and the second analog signal are combined through an adder and amplified and output through a multiplier;
the binary digit frequency expression is:
further, in the step S3, a local oscillation signal is further provided, and the local oscillation signal and the received modulated signal are mixed to output an amplitude-modulated wave with a preset specification, and the amplitude-modulated wave is input into the intermediate frequency amplifier module for amplification.
Further, in the step S4, the method further includes a low-pass filter, wherein an envelope detector is cascaded with the low-pass filter, and the envelope detector outputs a signal and then filters the signal through the low-pass filter, wherein the detected envelope is allowed to pass through the first follower and is recovered as an analog signal, and wherein the detected waveform is picked up and outputted by the high-frequency band-pass filter and the low-frequency high-pass filter of the second follower.
Further, in the step S1, the analog signal is output after being subjected to amplitude modulation.
Has the advantages compared with the prior art that,
currently, conventional transceiving devices are usually single-way transceiving and only transmit and receive a single signal. The application provides a novel design idea, which is to carry out mixed transmission on a digital signal and an analog signal.
The modulation and demodulation process uses an envelope detector and a band-pass filter, and can use a digital modulation method, and the band-pass filter is used for demodulation during demodulation to demodulate 0 and 1 represented by the signals.
The existing receiving and transmitting technology only considers that one voice signal is transmitted under the same frequency band, and the original audio signal is directly used for modulating and generating the FM modulation signal. Compared with the prior art, the application adopts the principles of simultaneous transmission of digital signals and voice signals, analog modulation and demodulation and digital modulation and demodulation to realize the first modulation and then mixed transmission.
The application adopts the principle of analog modulation and demodulation and digital modulation and demodulation to realize the mixed transmission after modulation. The main form is that a signal generator generates a periodic low-frequency signal, a voice signal is subjected to AM modulation, and then an envelope detector is used for filtering an envelope, wherein the envelope is the voice signal needed by people.
Drawings
Fig. 1 is a schematic diagram of a digital-analog signal hybrid transmission method.
Fig. 2 is a schematic diagram of a receiving portion of a digital-analog signal hybrid transmission method.
Fig. 3 is a flow chart of a mixing module of the digital analog signal mixing transmission method.
Fig. 4 is a schematic diagram of a further disclosure of the mixing portion of the digital-to-analog signal mixing transmission method.
Fig. 5 is a schematic diagram of a further disclosure of the receiving portion of the digital-to-analog signal hybrid transmission method.
Detailed Description
In the following description, for purposes of explanation and not limitation, specific details are set forth such as the particular system architecture, techniques, etc., in order to provide a thorough understanding of the embodiments of the present application. It will be apparent, however, to one skilled in the art that the present application may be practiced in other embodiments that depart from these specific details. In other instances, detailed descriptions of well-known systems, devices, circuits, and methods are omitted so as not to obscure the description of the present application with unnecessary detail.
It should be understood that the terms "comprises" and/or "comprising," when used in this specification and the appended claims, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.
It should also be understood that the term "and/or" as used in the present specification and the appended claims refers to any and all possible combinations of one or more of the associated listed items, and includes such combinations.
As used in the present description and the appended claims, the term "if" may be interpreted as "when..once" or "in response to a determination" or "in response to detection" depending on the context. Similarly, the phrase "if a determination" or "if a [ described condition or event ] is detected" may be interpreted in the context of meaning "upon determination" or "in response to determination" or "upon detection of a [ described condition or event ]" or "in response to detection of a [ described condition or event ]".
Furthermore, the terms "first," "second," "third," and the like in the description of the present specification and in the appended claims, are used for distinguishing between descriptions and not necessarily for indicating or implying a relative importance.
Reference in the specification to "one embodiment" or "some embodiments" or the like means that a particular feature, structure, or characteristic described in connection with the embodiment is included in one or more embodiments of the application. Thus, appearances of the phrases "in one embodiment," "in some embodiments," "in other embodiments," and the like in the specification are not necessarily all referring to the same embodiment, but mean "one or more but not all embodiments" unless expressly specified otherwise. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless expressly specified otherwise.
Embodiment 1 as shown in fig. 1, there is provided a digital-analog signal hybrid transmission method comprising a preamble stage,
first, there is an analog modulation stage, which adopts an amplitude modulation method to capture noise or discrete electromagnetic waves in daily life, and an analog signal is sent to an adder.
The simultaneous digital modulation phase and the digital alignment adopts a frequency modulation mode. The digital signal is changed into a binary signal, the number "0" is defined as 100Hz, the number "1" is defined as 3000Hz, and the emitted wave has a waveform of two frequencies.
It follows the equation that,
let the symbol "1" correspond to the carrier frequency f 1 (ω 1 ) "0" corresponds to carrier frequency f 2 (ω 2 ) Then at a duration of one symbol T B In this, the 2FSK signal generated by the transmitting end can be expressed as
The analog signal and the digital signal are simultaneously input into an adder for combining processing, and the voice signal can be a sine wave between 50Hz and 10KHz or music. The digital signal is any four-bit 0-9 digit keyed in by a screen, the signal generator generates a periodic low-frequency signal, the DDS generates a carrier signal of 20MHz to 30MHz, the low-frequency signal is multiplied by the carrier signal to obtain an amplitude modulation signal, the multiplier outputs the combined signal and the carrier signal, the power amplifier amplifies the power of the signal, and the antenna sends out a modulation part for mixed transmission to finish;
the amplitude modulation method comprises the following steps:
amplitude modulation is a process of controlling the amplitude of a high frequency carrier by a modulation signal so as to linearly change with the modulation signal.
Let sine carrier wave be
Wherein: a is carrier amplitude; omega c Is the carrier angular frequency;is the initial phase of the carrier.
The amplitude modulated signal can be generally expressed as, according to a modulation definition
s m (t)＝Am(t)cosω c t
(2)
Wherein: m (t) is baseband modulation signal
Assuming that the spectrum of the modulated signal M (t) is M (ω), it is not difficult to obtain the modulated signal s from equation (2) m Spectrum of (t):
as can be seen from the above formula, on the waveform, the amplitude of the amplitude modulated signal varies in proportion to the law of the baseband signal; in terms of spectral structure, its spectrum is simply a shift (accurate to a constant factor) of the spectrum of the baseband signal in the frequency domain. Since this shifting is linear, amplitude modulation is often also referred to as linear modulation.
Standard amplitude modulation is conventional double sideband modulation, abbreviated as Amplitude Modulation (AM). Assuming that the average value of the modulated signal m (t) is 0, it is superimposed by a DC offset A 0 And multiplying the signal with the carrier wave to form an amplitude modulation signal. The time domain expression is that
s AM (t)＝[A 0 +m(t)]cosω c t＝A 0 cosω c t+m(t)cosω c t
(4)
Wherein: a is that 0 Is an externally added direct current component; m (t) may be a deterministic signal or a random signal.
If m (t) is a deterministic signal, the spectrum of the AM signal is
As shown in fig. 5, the demodulation process is started, the signal sent by the transmitting end received by the antenna is sent to the small signal tuning amplifier, the frequency of the small signal tuning amplifier is consistent with the frequency of the transmitting party, the received signal is amplified and sent to the frequency mixing module, the frequency mixing module is adopted by the frequency mixer, the local oscillation signal sent to the frequency mixing module can use the LC oscillator or the crystal oscillator, the amplitude modulation wave of about 30MHz is output after frequency mixing, the intermediate amplification is the intermediate frequency amplifier module, and the detection, the low amplification and the AGC are the same module in the figure, namely the diode detection and the AGC module. The signal is restored by the low-pass filter through the envelope detector, then the signal is divided into two paths by the first follower and the second follower, one path of the demodulated voice signal is the output signal of the envelope detector, wherein the detected envelope is allowed to pass through the first follower and is restored into an analog signal, the envelope detector is used for filtering the envelope, and the envelope is the voice signal needed by people.
The other path passes through a high-frequency band-pass filter and a low-frequency high-pass filter, wherein the detected waveform is picked up and output by the high-frequency band-pass filter and the low-frequency high-pass filter of the second follower, the center frequencies of the two band-pass filters are respectively 100Hz and 3000Hz, the output is 0 when the 100Hz band-pass filter detects the wave, the output is 1 when the 3000Hz band-pass filter detects the wave, and the 0 and the 1 are demodulated and combined according to the original waveform time sequence mode.
The equipment for realizing the method comprises the following steps:
the digital-analog signal mixed transmission transceiver uses a high-frequency signal source as a carrier wave at the transmitting side, the frequency of the high-frequency signal source is set to be 20-30MHz, and the audio signal source can be speech, music or fixed single audio. The high-frequency signal and the audio signal are amplitude modulated and then become amplitude modulated waves, and then are sent to a high-frequency power amplifier, amplified by the high-frequency power amplifier and then transmitted out through an antenna; and at the receiving side, the signal sent by the sending side and received by the antenna is sent to a small signal tuning amplifier, the frequency of the small signal tuning amplifier is consistent with the frequency of the sending side, the received signal is amplified and sent to a mixer, the mixer adopts an AD835 multiplier mixing module, the local oscillator signal sent to the mixer can use an LC oscillator or a crystal oscillator, amplitude modulation waves of about 30MHz are output after mixing, the middle amplification is an intermediate frequency amplifier module, the waveform consistent with the audio signal source at the sending side is output after detection, and the signal output by the low amplification is sent to the power amplification input end of the low-frequency signal source part of the bottom plate to emit sound.
It will be apparent to those skilled in the art that, for convenience and brevity of description, only the above-described division of the functional units and modules is illustrated, and in practical application, the above-described functional distribution may be performed by different functional units and modules according to needs, i.e. the internal structure of the apparatus is divided into different functional units or modules to perform all or part of the above-described functions. The functional units and modules in the embodiment may be integrated in one processing unit, or each unit may exist alone physically, or two or more units may be integrated in one unit, where the integrated units may be implemented in a form of hardware or a form of a software functional unit. In addition, the specific names of the functional units and modules are only for distinguishing from each other, and are not used for limiting the protection scope of the present application. The specific working process of the units and modules in the above system may refer to the corresponding process in the foregoing method embodiment, which is not described herein again.
In the foregoing embodiments, the descriptions of the embodiments are emphasized, and in part, not described or illustrated in any particular embodiment, reference is made to the related descriptions of other embodiments.
Those of ordinary skill in the art will appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the solution. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.
In the embodiments provided in the present application, it should be understood that the disclosed apparatus/terminal device and method may be implemented in other manners. For example, the apparatus/terminal device embodiments described above are merely illustrative, e.g., the division of the modules or units described above is merely a logical function division, and there may be additional divisions in actual implementation, e.g., multiple units or plug-ins may be combined or integrated into another system, or some features may be omitted or not performed. Alternatively, the coupling or direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection via interfaces, devices or units, which may be in electrical, mechanical or other forms.
The units described above as separate components may or may not be physically separate, and components shown as units may or may not be physical units, may be located in one place, or may be distributed over a plurality of 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 the embodiments of the present application may be integrated in one processing unit, or each unit may exist alone physically, or two or more units may be integrated in one unit. The integrated units may be implemented in hardware or in software functional units.
The integrated modules/units described above, if implemented in the form of software functional units and sold or used as stand-alone products, may be stored in a computer readable storage medium. Based on such understanding, the present application may implement all or part of the flow of the above-described method embodiments, or may be implemented by a computer program to instruct related hardware, where the above-described computer program may be stored in a computer readable storage medium, where the computer program, when executed by a processor, may implement the steps of the above-described method embodiments. The computer program comprises computer program code, and the computer program code can be in a source code form, an object code form, an executable file or some intermediate form and the like. The computer readable medium may include: any entity or device capable of carrying the computer program code described above, a recording medium, a U disk, a removable hard disk, a magnetic disk, an optical disk, a computer Memory, a Read-Only Memory (ROM), a random access Memory (RAM, random Access Memory), an electrical carrier signal, a telecommunications signal, a software distribution medium, and so forth. It should be noted that the content of the computer readable medium described above can be appropriately increased or decreased according to the requirements of the jurisdiction's legislation and the patent practice, for example, in some jurisdictions, the computer readable medium does not include electrical carrier signals and telecommunication signals according to the legislation and the patent practice.
The above embodiments are only for illustrating the technical solution of the present application, and not for limiting the same; although the application has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present application, and are intended to be included in the scope of the present application.
Claims (5)
1. A digital-analog signal mixed transmission method is characterized by comprising the following steps,
s1, respectively transmitting a digital signal and an analog signal to a frequency mixing module, wherein the frequency mixing module combines the digital signal and the analog signal into a modulation signal, and two different frequency heights are respectively set for different physical quantities of the digital signal;
s2, amplifying the modulated signal to a preset intensity and then sending the amplified modulated signal to a receiving end;
s3, the receiving end receives the modulation signal, and then sends the modulation signal to a tuning amplifier to amplify a high-frequency signal and sends the high-frequency signal to an envelope detector;
s4, demodulating the signals by an envelope detector, limiting and obtaining envelope contents to be processed in the demodulation process, wherein the signals carried by the envelope contents are analog signals in the step S1, the analog signals are output to a first follower, the first follower outputs the envelope contents, namely, the analog signals in the step S1 are obtained at a receiving end, the envelope detector simultaneously inputs the signals into a high-frequency band-pass filter and a low-frequency high-pass filter, and the high-frequency band-pass filter and the low-frequency high-pass filter respectively pick up different frequencies and convert the different frequencies into corresponding physical quantities and then output digital signals again according to a preset sequence combination.
2. The method for mixed transmission of digital and analog signals according to claim 1, wherein the voice signal is a first analog signal in the form of a carrier wave after being recorded, the digital signal is modulated into a second analog signal by binary digital frequency, and the first analog signal and the second analog signal are combined by an adder and amplified and output by a multiplier;
the binary digit frequency expression is:
3. the method according to claim 1, wherein in the step S3, a local oscillation signal is further provided, and the local oscillation signal and the received modulated signal are mixed to output an amplitude-modulated wave with a preset specification, and the amplitude-modulated wave is amplified by the intermediate frequency amplifier module.
4. The method according to claim 1, further comprising a low-pass filter, wherein the envelope detector is cascaded with the low-pass filter, and wherein the envelope detector outputs a signal that is filtered by the low-pass filter, wherein the detected envelope is allowed to pass through the first follower and is recovered as an analog signal, and wherein the detected waveform is picked up and outputted by the high-band-pass filter and the low-frequency high-pass filter of the second follower.
5. The method of claim 2, wherein the step S1 modulates the signal in an amplitude modulation manner during the combining process.
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