CN108155913B - FM signal squelch method, apparatus and system - Google Patents
FM signal squelch method, apparatus and system Download PDFInfo
- Publication number
- CN108155913B CN108155913B CN201810033697.0A CN201810033697A CN108155913B CN 108155913 B CN108155913 B CN 108155913B CN 201810033697 A CN201810033697 A CN 201810033697A CN 108155913 B CN108155913 B CN 108155913B
- Authority
- CN
- China
- Prior art keywords
- signal
- noise elimination
- sampling
- threshold value
- noise
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Classifications
-
- 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
- H04B1/0003—Software-defined radio [SDR] systems, i.e. systems wherein components typically implemented in hardware, e.g. filters or modulators/demodulators, are implented using software, e.g. by involving an AD or DA conversion stage such that at least part of the signal processing is performed in the digital domain
- H04B1/0007—Software-defined radio [SDR] systems, i.e. systems wherein components typically implemented in hardware, e.g. filters or modulators/demodulators, are implented using software, e.g. by involving an AD or DA conversion stage such that at least part of the signal processing is performed in the digital domain wherein the AD/DA conversion occurs at radiofrequency or intermediate frequency stage
- H04B1/001—Channel filtering, i.e. selecting a frequency channel within the SDR system
-
- 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
- H04B1/0003—Software-defined radio [SDR] systems, i.e. systems wherein components typically implemented in hardware, e.g. filters or modulators/demodulators, are implented using software, e.g. by involving an AD or DA conversion stage such that at least part of the signal processing is performed in the digital domain
- H04B1/0007—Software-defined radio [SDR] systems, i.e. systems wherein components typically implemented in hardware, e.g. filters or modulators/demodulators, are implented using software, e.g. by involving an AD or DA conversion stage such that at least part of the signal processing is performed in the digital domain wherein the AD/DA conversion occurs at radiofrequency or intermediate frequency stage
-
- 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
- H04B1/0003—Software-defined radio [SDR] systems, i.e. systems wherein components typically implemented in hardware, e.g. filters or modulators/demodulators, are implented using software, e.g. by involving an AD or DA conversion stage such that at least part of the signal processing is performed in the digital domain
- H04B1/0007—Software-defined radio [SDR] systems, i.e. systems wherein components typically implemented in hardware, e.g. filters or modulators/demodulators, are implented using software, e.g. by involving an AD or DA conversion stage such that at least part of the signal processing is performed in the digital domain wherein the AD/DA conversion occurs at radiofrequency or intermediate frequency stage
- H04B1/0014—Software-defined radio [SDR] systems, i.e. systems wherein components typically implemented in hardware, e.g. filters or modulators/demodulators, are implented using software, e.g. by involving an AD or DA conversion stage such that at least part of the signal processing is performed in the digital domain wherein the AD/DA conversion occurs at radiofrequency or intermediate frequency stage using DSP [Digital Signal Processor] quadrature modulation and demodulation
-
- 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
- H04B1/0003—Software-defined radio [SDR] systems, i.e. systems wherein components typically implemented in hardware, e.g. filters or modulators/demodulators, are implented using software, e.g. by involving an AD or DA conversion stage such that at least part of the signal processing is performed in the digital domain
- H04B1/0007—Software-defined radio [SDR] systems, i.e. systems wherein components typically implemented in hardware, e.g. filters or modulators/demodulators, are implented using software, e.g. by involving an AD or DA conversion stage such that at least part of the signal processing is performed in the digital domain wherein the AD/DA conversion occurs at radiofrequency or intermediate frequency stage
- H04B1/0017—Digital filtering
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Noise Elimination (AREA)
Abstract
The present invention provides a kind of FM signal squelch methods, apparatus and system, are related to wireless communication technique field, and this method is applied to Digitization Software radio platforms, comprising: obtains the sample signal strength of the corresponding digital sampled signal of FM signal；Judge whether the sample signal strength is less than preset noise elimination threshold value；When the judgment result is yes, noise elimination operation is carried out to the FM signal, so that the FM signal enters noise-limited condition.FM signal squelch method provided by the invention, apparatus and system, improve the consistency of noise elimination effect, avoid during noise elimination and accidental burst noise occur, reduce DSP operation amount, to save DSP resource, improve the stability of system.
Description
Technical field
The present invention relates to wireless communication technique fields, more particularly, to a kind of FM signal squelch method, apparatus and system.
Background technique
Traditional simulation FM (Frequency Modulation, frequency modulation) radio station, FM signal (FM signal) it is weaker or
When noise is relatively low, the very big audio-frequency noise of frequency discriminator meeting output amplitude, significantly noise can enable listener not relax very much for these
Clothes, need to introduce squelch circuit thus, i.e., when (> 3000Hz) energy is excessive outside voiced band, it is believed that and it is that current output is invalid,
Thus audio output is closed, to prevent docking receipts person from causing unnecessary interference.
Traditional noise elimination scheme is the out-of-band noise (> 3000Hz) based on obtained audio signal after FM signal frequency discrimination
Energy size decides whether noise elimination, if out-of-band noise energy is greater than some threshold value fixed, then it is assumed that be noise energy
It is too big, need noise elimination, on the contrary it is then without noise elimination.Circuit of the traditional simulation radio station FM squelch algorithm dependent on simulation, need into
It filters outside row voiced band, the thresholding operation such as relatively, is suitable for traditional simulation frequency detection mode, noise elimination effect is dependent on related member
The precision of device has accidental since the discreteness of component causes the consistency of noise elimination effect poor, and during noise elimination
Burst noise.
In the wireless level of Digitization Software for being based on DSP (Digital Signal Processing, Digital Signal Processing)
On platform (platform realizes digital frequency discrimination, abbreviation DSP platform with software mode), although traditional noise elimination operating mode still can be with
Operation, but need to carry out the audio signal after frequency discrimination the series of computation such as filtering outside voiced band, it will increase the operation of DSP in this way
Amount, and then lead to system fluctuation of service.
Summary of the invention
In view of this, the purpose of the present invention is to provide a kind of FM signal squelch method, apparatus and system, it is quiet to improve
The consistency for effect of making an uproar avoids accidental burst noise occur during noise elimination, reduces DSP operation amount, to save DSP money
The stability of system is improved in source.
In a first aspect, it is wireless to be applied to Digitization Software the embodiment of the invention provides a kind of FM signal squelch method
Level platform, which comprises obtain the sample signal strength of the corresponding digital sampled signal of FM signal；Judge the sampling
Whether signal strength is less than preset noise elimination threshold value；When the judgment result is yes, noise elimination operation is carried out to the FM signal,
So that the FM signal enters noise-limited condition.
With reference to first aspect, the embodiment of the invention provides the first possible embodiments of first aspect, wherein institute
Stating digital sampled signal includes if sampling signal；The sampled signal for obtaining the corresponding digital sampled signal of FM signal is strong
Degree, comprising: obtain if sampling data of the corresponding if sampling signal of FM signal within the setting period, the if sampling
Data include the range value of multiple sample signals；The average letter of the if sampling signal is calculated according to the if sampling data
Number power, obtains the sample signal strength of the if sampling signal.
The possible embodiment of with reference to first aspect the first, the embodiment of the invention provides second of first aspect
Possible embodiment, wherein the method also includes: the intermediate frequency being calculated is adopted according to preset calibration calibration value
The sample signal strength of sample signal is calibrated, the sample signal strength after being calibrated.
The possible embodiment of second with reference to first aspect, the embodiment of the invention provides the third of first aspect
Possible embodiment, wherein the calibration calibration value determines by the following method: calculating separately in the defeated of the FM signal
Export the measuring signal intensity without modulated signal of multiple and different signal strengths of feed-in；According to each measuring signal intensity
With corresponding actual signal intensity, the calibration value of each no modulated signal is calculated；It averages to each calibration value,
Obtain the calibration calibration value.
With reference to first aspect, the embodiment of the invention provides the 4th kind of possible embodiments of first aspect, wherein institute
It states when the judgment result is yes, noise elimination operation is carried out to the FM signal, comprising: judge that the sample signal strength is less than institute
Whether the first read-around ratio for stating noise elimination threshold value is greater than the noise elimination frequency threshold value of setting；If first read-around ratio is greater than
The noise elimination frequency threshold value then carries out noise elimination operation to the FM signal.
With reference to first aspect, the embodiment of the invention provides the 5th kind of possible embodiments of first aspect, wherein institute
Stating noise elimination operation includes mute or output comfort noise.
With reference to first aspect, the embodiment of the invention provides the 6th kind of possible embodiments of first aspect, wherein when
When the FM signal is in noise-limited condition, the method also includes: it is preset to judge whether the sample signal strength is greater than
Exit threshold value；Wherein, the threshold value that exits is greater than the noise elimination threshold value；If so, judging the sample signal strength
Frequency threshold value is exited greater than what whether second read-around ratio for exiting threshold value was greater than setting；If described second continuous time
Number be greater than it is described exit frequency threshold value, then stop operating the noise elimination of the FM signal so that the FM signal exit it is quiet
It makes an uproar state.
Second aspect, the embodiment of the present invention also provide a kind of FM signal static limiter, and it is wireless to be applied to Digitization Software
Level platform, described device include: acquisition module, and the sampled signal for obtaining the corresponding digital sampled signal of FM signal is strong
Degree；Judgment module, for judging whether the sample signal strength is less than preset noise elimination threshold value；Noise elimination module, for working as
Judging result is noise elimination operation to be carried out to the FM signal, so that the FM signal enters noise-limited condition when being.
The third aspect, the embodiment of the present invention also provide a kind of FM signal squelch system, including Digitization Software radio
Platform；The Digitization Software radio platforms include memory, processor, and being stored in the memory can be in the processing
The computer program run on device, the processor realize above-mentioned first aspect and its any when executing the computer program
Method described in possible embodiment；The Digitization Software radio platforms are for exporting after noise elimination processing and frequency discrimination
Audio signal.
In conjunction with the third aspect, the embodiment of the invention provides the first possible embodiments of the third aspect, wherein institute
The system of stating further includes sequentially connected pre-amplifying module, mixing and filtering module and if sampling module；The preposition amplification mould
Block is connect with the delivery outlet of the FM signal；The if sampling module is connect with the Digitization Software radio platforms,
For exporting the corresponding if sampling data of the FM signal to the Digitization Software radio platforms.
The embodiment of the present invention bring it is following the utility model has the advantages that
FM signal squelch method provided in an embodiment of the present invention is applied to Digitization Software radio platforms, this method packet
It includes: obtaining the sample signal strength of the corresponding digital sampled signal of FM signal；It is pre- to judge whether the sample signal strength is less than
If noise elimination threshold value；When the judgment result is yes, to the FM signal carry out noise elimination operation so that the FM signal enter it is quiet
It makes an uproar state.Since the above process is totally digitilized process, do not need to increase relevant analog circuit component, therefore avoid member
The inconsistent situation of noise elimination effect caused by device discreteness, and noise elimination result is expectable, avoids even during noise elimination
The burst noise situation of hair；This method is suitable for Digitization Software radio platforms, does not need to carry out filtering etc. one outside voiced band
Series calculates and operation, namely without too many additional calculating and operation, therefore can save a large amount of DSP resources.Therefore, of the invention
FM signal squelch method, the apparatus and system of embodiment offer improve the consistency of noise elimination effect, avoid noise elimination process
It is middle accidental burst noise occur, DSP operation amount is reduced, to save DSP resource, improves the stability of system.
Other features and advantages of the present invention will illustrate in the following description, also, partly become from specification
It obtains it is clear that understand through the implementation of the invention.The objectives and other advantages of the invention are in specification, claims
And specifically noted structure is achieved and obtained in attached drawing.
To enable the above objects, features and advantages of the present invention to be clearer and more comprehensible, preferred embodiment is cited below particularly, and cooperate
Appended attached drawing, is described in detail below.
Detailed description of the invention
It, below will be to specific in order to illustrate more clearly of the specific embodiment of the invention or technical solution in the prior art
Embodiment or attached drawing needed to be used in the description of the prior art be briefly described, it should be apparent that, it is described below
Attached drawing is some embodiments of the present invention, for those of ordinary skill in the art, before not making the creative labor
It puts, is also possible to obtain other drawings based on these drawings.
Fig. 1 is a kind of flow diagram of FM signal squelch method provided in an embodiment of the present invention；
Fig. 2 is the flow diagram that a kind of calibration calibration value provided in an embodiment of the present invention determines method；
Fig. 3 is the flow diagram of another FM signal squelch method provided in an embodiment of the present invention；
Fig. 4 is a kind of structural schematic diagram of FM signal static limiter provided in an embodiment of the present invention；
Fig. 5 is a kind of structural schematic diagram of Digitization Software radio platforms provided in an embodiment of the present invention；
Fig. 6 is a kind of structural schematic diagram of FM signal squelch system provided in an embodiment of the present invention.
Specific embodiment
In order to make the object, technical scheme and advantages of the embodiment of the invention clearer, below in conjunction with attached drawing to the present invention
Technical solution be clearly and completely described, it is clear that described embodiments are some of the embodiments of the present invention, rather than
Whole embodiments.Based on the embodiments of the present invention, those of ordinary skill in the art are not making creative work premise
Under every other embodiment obtained, shall fall within the protection scope of the present invention.
Noise elimination scheme traditional at present is suitable for traditional simulation frequency detection mode, since the discreteness of component leads to noise elimination
The consistency of effect is poor, and accidental burst noise is had during noise elimination；It is not suitable for DSP platform, is applied to DSP platform
When, the operand of DSP leads to greatly system fluctuation of service.Based on this, a kind of FM signal noise elimination provided in an embodiment of the present invention
The consistency of noise elimination effect can be improved in method, apparatus and system, avoids accidental burst noise occur during noise elimination, drops
Low DSP operation amount improves the stability of system to save DSP resource.
FM signal squelch method provided in an embodiment of the present invention is applied to Digitization Software radio platforms.It is flat in DSP
On platform, realize that digital frequency discrimination needs to compensate parastic modulation during frequency discrimination with software mode, it is therefore desirable in real time
Calculate the signal strength of carrier wave, i.e. RSSI (Received Signal Strength Indication, received signal intensity
Instruction) value.RSSI value directly reflects signal strength.It is theoretical according to FM frequency discrimination, when the signal-to-noise ratio of FM signal is lower than some thresholding
When (generally take SNR (SIGNAL-NOISE RATIO, signal-to-noise ratio)=10dB), frequency discrimination quality of output signals can be deteriorated sharply, i.e.,
Noise component(s) can increase sharply, and lead to audio quality sharp fall, and intelligibility reduces, it is considered to be noise.In most of feelings
Under condition, the signal-to-noise ratio of FM signal depends on signal strength (signal power) and receives circuit internal thermal noise intensity ratio, generally
Think that receive circuit internal thermal noise remains constant substantially, therefore the signal-to-noise ratio of FM signal is in general, is dependent only on
The signal strength of FM signal, thus the embodiment of the present invention carries out noise elimination operation according to the signal strength of FM signal.
For convenient for understanding the present embodiment, first to a kind of FM signal noise elimination side disclosed in the embodiment of the present invention
Method describes in detail.
Embodiment one:
Fig. 1 is a kind of flow diagram of FM signal squelch method provided in an embodiment of the present invention, and this method is applied to
Digitization Software radio platforms, as shown in Figure 1, this method including the following steps:
Step S102 obtains the sample signal strength of the corresponding digital sampled signal of FM signal.
Since this method is applied to Digitization Software radio platforms, what is received is after FM signal digitizes
Digital sampled signal.By taking digital sampled signal is if sampling signal as an example, step S102 is specific as follows:
First obtain if sampling data of the corresponding if sampling signal of FM signal within the setting period, the if sampling
Data include the range value of multiple sample signals.The setting period can be arranged according to actual needs, here without limitation.Then root
The average signal power that the if sampling signal is calculated according to if sampling data, the sampled signal for obtaining if sampling signal are strong
Degree.Sample signal strength RSSI can be calculated according to following formula (1) and (2)dBm:
RSSIdBm=10logRSSIA(2),
Wherein, N indicates a calculating cycle (setting period) sample number calculated, and theoretically, the sample number is bigger, then
Calculating error is smaller, and emulation shows: when sample number is greater than 1200, calculating error less than 0.5%, not will cause to subsequent calculating
It significantly affects；siIndicate the range value (numerical value after removal direct current) of i-th of sample signal.
In actual use, each specific radio circuit can be re-scaled, i.e., formula (2) is modified, is added
Upper amendment number.If such as amendment number is 10log (1mw), formula (2) amendment are as follows: RSSIdBm=10log (RSSIA/
1mW)。
In view of since FM signal output to during being converted to digital sampled signal, because it is at different levels it is preposition amplification, in
Putting equal circuits, there are inconsistencies, and the signal strength being calculated can be made with actual value, and there is a certain error, the above method
Further include: the sample signal strength for the if sampling signal being calculated is calibrated according to preset calibration calibration value and (is mended
Repay), the sample signal strength after being calibrated.Calibration calibration value is that the actual value of the port RF feed-in is calculated with according to formula (2)
The obtained difference between value, for the preset parameter of preservation；For different RF plates, it is not identical to calibrate calibration value.Through school
Quasi- sample signal strength is more true and reliable.
Sample signal strength RSSI after being calibrated according to following formula (3)dBm_real:
RSSIdBm_real=RSSIdBm_measured+RSSIoffset(3),
Wherein, RSSIdBm_measuredIndicate the above-mentioned sample signal strength being calculated, RSSIoffsetIndicate calibration calibration
Value.
Step S104, judges whether above-mentioned sample signal strength is less than preset noise elimination threshold value.
Wherein, noise elimination threshold value can be arranged according to actual needs, not limit this.Such as noise elimination threshold value can be with
For -115dBm.When sample signal strength is less than noise elimination threshold value, i.e., judging result is when being, to execute step S106；Conversely,
It is when sample signal strength is more than or equal to noise elimination threshold value, i.e., normal to export when judging result is no, and re-execute step
Rapid S102.
Step S106 carries out noise elimination operation to above-mentioned FM signal when above-mentioned judging result, which is, is, so that the frequency modulation is believed
Number enter noise-limited condition.
Above-mentioned noise elimination operation includes mute or output comfort noise.It is mute to refer to as needed, close the sound of loudspeaker
Output, or only export a direct current signal.Comfort noise is a kind of special noise, refers to that, by specific sound, playing makes
The effect that people loosens or arouses vigilance.Full 0 (completely mute) can have both been exported in noise elimination, can also export specific noise
Or audio-frequency information, it allows user clearly to perceive this etching system and is in noise-limited condition.
Due to inherently needing to calculate the energy of input signal during digital frequency discrimination, that is, calculateSo this process will not increase due to squelch algorithm and additionally, the above method is without too
Mostly additional calculating and operation can save a large amount of DSP resources, to improve the stability of system.
FM signal squelch method provided in an embodiment of the present invention is applied to Digitization Software radio platforms, this method packet
It includes: obtaining the sample signal strength of the corresponding digital sampled signal of FM signal；It is pre- to judge whether the sample signal strength is less than
If noise elimination threshold value；When the judgment result is yes, to the FM signal carry out noise elimination operation so that the FM signal enter it is quiet
It makes an uproar state.Since the above process is totally digitilized process, do not need to increase relevant analog circuit component, therefore avoid member
The inconsistent situation of noise elimination effect caused by device discreteness, and noise elimination result is expectable, avoids even during noise elimination
The burst noise situation of hair；This method is suitable for Digitization Software radio platforms, does not need to carry out filtering etc. one outside voiced band
Series calculates and operation, namely without too many additional calculating and operation, therefore can save a large amount of DSP resources.Therefore, of the invention
The FM signal squelch method that embodiment provides improves the consistency of noise elimination effect, avoid during noise elimination occur it is accidental
Burst noise reduces DSP operation amount, to save DSP resource, improves the stability of system.
Fig. 2 is the flow diagram that a kind of calibration calibration value provided in an embodiment of the present invention determines method, as shown in Fig. 2,
Above-mentioned calibration calibration value is determined by following steps:
Step S202, calculate separately the delivery outlet feed-in of FM signal multiple and different signal strengths without modulated signal
Measuring signal intensity.
Step S204 calculates each no modulated signal according to each measuring signal intensity and corresponding actual signal intensity
Calibration value.
Step S206 averages to each calibration value, obtains calibration calibration value.
Below by respectively the delivery outlet feed-in -80dBm of RF signal, -100dBm without modulated signal for carry out it is specific
Explanation.Firstly, RF signal delivery outlet with comprehensive test instrument feed-in one without modulated signal, signal strength is -80dBm, is denoted as
RSSIdBm_-80dBm, the signal strength of feed-in is calculated according to formula (2) at this time, is denoted as RSSIdBm_-80dBm_measured, thus to obtain-
The calibration value without modulated signal of 80dBm are as follows: RSSIoffset_-80dBm=RSSIdBm_-80dBm-RSSIdBm_-80dBm_measured.According to
Same step, in the signal of the delivery outlet feed-in -100dBm of RF signal, the school without modulated signal of available -100dBm
Quasi- value RSSIoffset_-100dBm.Finally geometric average is asked to can be obtained calibration calibration value the calibration value obtained twice.
Fig. 3 is the flow diagram of another FM signal squelch method provided in an embodiment of the present invention.In view of working as
When RSSI value is in close proximity to some threshold value, it may appear that noise elimination operates oscillatory occurences, as shown in figure 3, this method includes following
Several steps:
Step S302 obtains if sampling data.
Step S304 calculates sample signal strength RSSI value.
Step S306 compensates (calibration) to above-mentioned RSSI value.
Step S308, judges whether compensated RSSI value is less than noise elimination threshold value.If so, executing step S310；Such as
Fruit is no, executes step S314.
Step S310, judges whether above-mentioned RSSI value is greater than the noise elimination of setting less than the first read-around ratio of noise elimination threshold value
Frequency threshold value.If so, executing step S312；If not, directly exporting, and it re-execute the steps S302.
Noise elimination frequency threshold value can be arranged according to actual needs, not limit this.For example, noise elimination frequency threshold value is 2, if
First read-around ratio be 3, i.e., RSSI value continuous 3 times be less than noise elimination threshold value, then follow the steps S312.
Step S312 carries out noise elimination operation to above-mentioned FM signal.Then it re-execute the steps S302.
Step S314 judges whether above-mentioned RSSI value is greater than and preset exits threshold value.If so, executing step S316；
If not, re-executeing the steps S302.
Wherein, threshold value is exited greater than above-mentioned noise elimination threshold value.When RSSI value is in close proximity to some threshold value, due to
The variation of signal, may last moment be greater than threshold value, subsequent time be less than threshold value, if merely rely on RSSI value with
The size of threshold value compares, and will cause a little while has sound output, does not have sound output a little while, and such phenomenon is referred to as to vibrate.
To prevent noise elimination from operating oscillatory occurences, when from noise-limited condition to when non-quiet state transition, needing to increase in noise elimination threshold value
One rollback variable delta, delta perseverance is positive, namely exits threshold value=noise elimination threshold value+delta, therefore exit threshold value
Greater than noise elimination threshold value.Such as delta=3dB, when noise elimination threshold value is -115dBm, only when signal increases to -112dBm
When be likely to that noise elimination function can be closed.
Step S316, judges whether above-mentioned RSSI value is greater than exiting for setting greater than the second read-around ratio for exiting threshold value
Frequency threshold value.If so, executing step S318；If not, re-executeing the steps S302.
The above-mentioned frequency threshold value that exits can be arranged according to actual needs, not limit this.For example, exiting frequency threshold value and being
2, then only working as RSSI value continuous 3 times greater than threshold value is exited is to execute step S318.
Step S318 stops noise elimination operation, exits noise-limited condition.
Stop operating the noise elimination of above-mentioned FM signal, so that the FM signal exits noise-limited condition.Then it re-executes
Step S302.
For example, current noise elimination threshold value is -115dBm, delta=3dB, noise elimination frequency threshold value and to exit frequency threshold value equal
Be 2, if continuously calculated signal collected, be continuously available three signal strengths, such as -116dBm, -115.8dBm, -
116.2dBm, then system thinks that current input signal is too weak, will lead to noise and becomes larger, therefore system enters noise-limited condition, i.e., defeated
The comfort noise that full 0 or system give out.Conversely, when system is continuously available three signal strengths both greater than -112dBm (as -
111dBm, -110dBm, -111.5dBm), system will be considered that signal enhancing, closes noise elimination, frequency discrimination signal is exported.
The detailed process of the above-mentioned steps of the present embodiment can refer to foregoing teachings, and which is not described herein again.
The characteristics of combination software radio of the embodiment of the present invention, the signal strength by calculating FM signal carry out noise elimination, and
It is not according to traditional out-of-band noise method.Through practical proof, above-mentioned noise elimination scheme is feasible in DSP platform, achieve compared with
Good desired effect, shows the following aspects: 1, totally digitilized process, avoid as component discreteness and caused by
The inconsistent situation of noise elimination effect；2, as a result expectable (full 0 or comfort noise) during noise elimination, avoid accidental dash forward
Send out noise situations；3, it is suitable for Digitization Software radio platforms, without too many additional calculating and operation, can saves a large amount of
DSP resource.
Embodiment two:
Fig. 4 is a kind of structural schematic diagram of FM signal static limiter provided in an embodiment of the present invention, as shown in figure 4, should
Device is applied to Digitization Software radio platforms, which includes:
Module 42 is obtained, for obtaining the sample signal strength of the corresponding digital sampled signal of FM signal；
Judgment module 44, for judging whether above-mentioned sample signal strength is less than preset noise elimination threshold value；
Noise elimination module 46, for when the judgment result is yes, noise elimination operation being carried out to above-mentioned FM signal, so that the frequency modulation
Signal enters noise-limited condition.
FM signal static limiter provided in an embodiment of the present invention is applied to Digitization Software radio platforms, and the device is logical
It crosses and obtains the sample signal strength that module 42 obtains the corresponding digital sampled signal of FM signal；Judgment module 44 judges the sampling
Whether signal strength is less than preset noise elimination threshold value；When the judgment result is yes, noise elimination module 46 carries out the FM signal
Noise elimination operation, so that the FM signal enters noise-limited condition.Since the above process is totally digitilized process, do not need to increase related
Analog circuit component, therefore avoid the situation that noise elimination effect is inconsistent caused by component discreteness, and noise elimination knot
Fruit is expectable, avoids accidental burst noise situation during noise elimination；This method is suitable for the wireless level of Digitization Software
Platform does not need to carry out series of computation and the operation such as filtering outside voiced band, namely without too many additional calculating and operation, therefore
A large amount of DSP resources can be saved.Therefore, FM signal static limiter provided in an embodiment of the present invention improves the consistent of noise elimination effect
Property, avoiding noise elimination there is accidental burst noise in the process, reduces DSP operation amount, to save DSP resource, improves
The stability of system.
Embodiment three:
The embodiment of the invention provides a kind of FM signal squelch system, including Digitization Software radio platforms, the numbers
Word Software Radio platform is used to export the audio signal after noise elimination processing and frequency discrimination.Fig. 5 provides for the embodiment of the present invention
A kind of Digitization Software radio platforms structural schematic diagram, referring to Fig. 5, the embodiment of the present invention also provides a kind of digital soft
Part radio platforms 500, comprising: processor 50, memory 51, bus 52 and communication interface 53, the processor 50, communication connect
Mouth 53 and memory 51 are connected by bus 52；Processor 50 is used to execute the executable module stored in memory 51, such as
Computer program.
Wherein, memory 51 may include high-speed random access memory (RAM, Random Access Memory),
It may further include nonvolatile memory (non-volatile memory), for example, at least a magnetic disk storage.By at least
One communication interface 53 (can be wired or wireless) realizes the communication between the system network element and at least one other network element
Connection, can be used internet, wide area network, local network, Metropolitan Area Network (MAN) etc..
Bus 52 can be isa bus, pci bus or eisa bus etc..The bus can be divided into address bus, data
Bus, control bus etc..Only to be indicated with a four-headed arrow convenient for indicating, in Fig. 5, it is not intended that an only bus or
A type of bus.
Wherein, memory 51 is for storing program, and the processor 50 executes the journey after receiving and executing instruction
Sequence, method performed by the device that the stream process that aforementioned any embodiment of the embodiment of the present invention discloses defines can be applied to handle
In device 50, or realized by processor 50.
Processor 50 may be a kind of IC chip, the processing capacity with signal.During realization, above-mentioned side
Each step of method can be completed by the integrated logic circuit of the hardware in processor 50 or the instruction of software form.Above-mentioned
Processor 50 can be general processor, including central processing unit (Central Processing Unit, abbreviation CPU), network
Processor (Network Processor, abbreviation NP) etc.；It can also be digital signal processor (Digital Signal
Processing, abbreviation DSP), specific integrated circuit (Application Specific Integrated Circuit, referred to as
ASIC), ready-made programmable gate array (Field-Programmable Gate Array, abbreviation FPGA) or other are programmable
Logical device, discrete gate or transistor logic, discrete hardware components.It may be implemented or execute in the embodiment of the present invention
Disclosed each method, step and logic diagram.General processor can be microprocessor or the processor is also possible to appoint
What conventional processor etc..The step of method in conjunction with disclosed in the embodiment of the present invention, can be embodied directly in hardware decoding processing
Device executes completion, or in decoding processor hardware and software module combination execute completion.Software module can be located at
Machine memory, flash memory, read-only memory, programmable read only memory or electrically erasable programmable memory, register etc. are originally
In the storage medium of field maturation.The storage medium is located at memory 51, and processor 50 reads the information in memory 51, in conjunction with
Its hardware completes the step of above method.
Fig. 6 is a kind of structural schematic diagram of FM signal squelch system provided in an embodiment of the present invention, as shown in fig. 6, on
The system of stating further includes sequentially connected pre-amplifying module 601, mixing and filtering module 602 and if sampling module 603.
Specifically, pre-amplifying module 601 is connect with the delivery outlet of FM signal；If sampling module 603 and digitlization
Software Radio platform 500 connects, and for carrying out ADC under intermediate frequency, (Analog-to-Digital Converter, refers to analog/digital
Converter) sampling, the corresponding if sampling data of FM signal are exported to Digitization Software radio platforms 500.Preposition amplification
Module 601 can be, but not limited to as LNA (Low Noise Amplifier, low-noise amplifier).Above-mentioned mixing and filtering module
602 can be one or more, as shown in fig. 6, being mixed twice using two mixing and filtering modules 602.
As shown in fig. 6, RF signal is output to pre-amplifying module 601, through 601, two mixing and filterings of pre-amplifying module
Module 602 and if sampling module 603 become if sampling signal, are output in Digitization Software radio platforms 500, number
Change Software Radio platform 500 and noise elimination processing and frequency discrimination are carried out according to the if sampling signal, after the processing of output noise elimination and frequency discrimination
AF (audio frequency, audio) signal, while pass through AGC (Automatic Gain Control, automatic gain control
System) feed back to pre-amplifying module 601.
It is apparent to those skilled in the art that for convenience and simplicity of description, the system of foregoing description
It with the specific work process of device, can refer to corresponding processes in the foregoing method embodiment, details are not described herein.
FM signal static limiter provided in an embodiment of the present invention and system, it is quiet with FM signal provided by the above embodiment
Method for de-noising technical characteristic having the same reaches identical technical effect so also can solve identical technical problem.
Unless specifically stated otherwise, the opposite step of the component and step that otherwise illustrate in these embodiments, digital table
It is not limit the scope of the invention up to formula and numerical value.
In all examples being illustrated and described herein, any occurrence should be construed as merely illustratively, without
It is as limitation, therefore, other examples of exemplary embodiment can have different values.
The flow chart and block diagram in the drawings show the system of multiple embodiments according to the present invention, method and computer journeys
The architecture, function and operation in the cards of sequence product.In this regard, each box in flowchart or block diagram can generation
A part of one module, section or code of table, a part of the module, section or code include one or more use
The executable instruction of the logic function as defined in realizing.It should also be noted that in some implementations as replacements, being marked in box
The function of note can also occur in a different order than that indicated in the drawings.For example, two continuous boxes can actually base
Originally it is performed in parallel, they can also be executed in the opposite order sometimes, and this depends on the function involved.It is also noted that
It is the combination of each box in block diagram and or flow chart and the box in block diagram and or flow chart, can uses and execute rule
The dedicated hardware based system of fixed function or movement is realized, or can use the group of specialized hardware and computer instruction
It closes to realize.
The computer program product of FM signal squelch method is carried out provided by the embodiment of the present invention, including stores place
The computer readable storage medium of the executable non-volatile program code of device is managed, the instruction that said program code includes can be used for
Previous methods method as described in the examples is executed, specific implementation can be found in embodiment of the method, and details are not described herein.
In several embodiments provided herein, it should be understood that disclosed systems, devices and methods, it can be with
It realizes by another way.The apparatus embodiments described above are merely exemplary, for example, the division of the unit,
Only a kind of logical function partition, there may be another division manner in actual implementation, in another example, multiple units or components can
To combine or be desirably integrated into another system, or some features can be ignored or not executed.Another point, it is shown or beg for
The mutual coupling, direct-coupling or communication connection of opinion can be through some communication interfaces, device or unit it is indirect
Coupling or communication connection can be electrical property, mechanical or other forms.
The unit as illustrated by the separation member may or may not be physically separated, aobvious as unit
The component shown may or may not be physical unit, it can and it is in one place, or may be distributed over multiple
In network unit.It can select some or all of unit therein according to the actual needs to realize the mesh of this embodiment scheme
's.
It, can also be in addition, the functional units in various embodiments of the present invention may be integrated into one processing unit
It is that each unit physically exists alone, can also be integrated in one unit with two or more units.
It, can be with if the function is realized in the form of SFU software functional unit and when sold or used as an independent product
It is stored in the executable non-volatile computer-readable storage medium of a processor.Based on this understanding, of the invention
Technical solution substantially the part of the part that contributes to existing technology or the technical solution can be with software in other words
The form of product embodies, which is stored in a storage medium, including some instructions use so that
One computer equipment (can be personal computer, server or the network equipment etc.) executes each embodiment institute of the present invention
State all or part of the steps of method.And storage medium above-mentioned includes: USB flash disk, mobile hard disk, read-only memory (ROM, Read-
Only Memory), random access memory (RAM, Random Access Memory), magnetic or disk etc. are various can be with
Store the medium of program code.
Finally, it should be noted that embodiment described above, only a specific embodiment of the invention, to illustrate the present invention
Technical solution, rather than its limitations, scope of protection of the present invention is not limited thereto, although with reference to the foregoing embodiments to this hair
It is bright to be described in detail, those skilled in the art should understand that: anyone skilled in the art
In the technical scope disclosed by the present invention, it can still modify to technical solution documented by previous embodiment or can be light
It is readily conceivable that variation or equivalent replacement of some of the technical features；And these modifications, variation or replacement, do not make
The essence of corresponding technical solution is detached from the spirit and scope of technical solution of the embodiment of the present invention, should all cover in protection of the invention
Within the scope of.Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.
Claims (9)
1. a kind of FM signal squelch method, which is characterized in that be applied to Digitization Software radio platforms, the method packet
It includes:
Obtain the sample signal strength of the corresponding digital sampled signal of FM signal；
Judge whether the sample signal strength is less than preset noise elimination threshold value；
When the judgment result is yes, noise elimination operation is carried out to the FM signal, so that the FM signal enters noise-limited condition；
The digital sampled signal includes if sampling signal；The sampling for obtaining the corresponding digital sampled signal of FM signal
Signal strength, comprising:
Obtain if sampling data of the corresponding if sampling signal of FM signal within the setting period, the if sampling data
Range value including multiple sample signals；
The average signal power that the if sampling signal is calculated according to the if sampling data obtains the if sampling letter
Number sample signal strength.
2. the method according to claim 1, wherein the method also includes:
The sample signal strength for the if sampling signal being calculated is calibrated according to preset calibration calibration value, is obtained
Sample signal strength after to calibration.
3. according to the method described in claim 2, it is characterized in that, the calibration calibration value determines by the following method:
Calculate separately the measurement letter without modulated signal in multiple and different signal strengths of the delivery outlet feed-in of the FM signal
Number intensity；
According to each measuring signal intensity and corresponding actual signal intensity, the calibration of each no modulated signal is calculated
Value；
It averages to each calibration value, obtains the calibration calibration value.
4. the method according to claim 1, wherein it is described when the judgment result is yes, to the FM signal
Carry out noise elimination operation, comprising:
Judge whether the sample signal strength is greater than the noise elimination of setting less than the first read-around ratio of the noise elimination threshold value
Number threshold value；
If first read-around ratio is greater than the noise elimination frequency threshold value, noise elimination operation is carried out to the FM signal.
5. the method according to claim 1, wherein noise elimination operation includes mute or output is comfortably made an uproar
Sound.
6. the method according to claim 1, wherein when the FM signal is in noise-limited condition, the side
Method further include:
Judge whether the sample signal strength is greater than and preset exits threshold value；Wherein, the threshold value that exits is greater than described
Noise elimination threshold value；
If so, judging that the sample signal strength is greater than whether second read-around ratio for exiting threshold value is greater than setting
Exit frequency threshold value；
If second read-around ratio is greater than the noise elimination operation exited frequency threshold value, stop to the FM signal,
So that the FM signal exits noise-limited condition.
7. a kind of FM signal static limiter, which is characterized in that be applied to Digitization Software radio platforms, described device packet
It includes:
Module is obtained, for obtaining the sample signal strength of the corresponding digital sampled signal of FM signal；
Judgment module, for judging whether the sample signal strength is less than preset noise elimination threshold value；
Noise elimination module, for when the judgment result is yes, noise elimination operation being carried out to the FM signal, so that the FM signal
Into noise-limited condition；
The digital sampled signal includes if sampling signal；The acquisition module is specifically used for:
Obtain if sampling data of the corresponding if sampling signal of FM signal within the setting period, the if sampling data
Range value including multiple sample signals；
The average signal power that the if sampling signal is calculated according to the if sampling data obtains the if sampling letter
Number sample signal strength.
8. a kind of FM signal squelch system, which is characterized in that including Digitization Software radio platforms；
The Digitization Software radio platforms include memory, processor, and being stored in the memory can be in the processing
The computer program run on device, the processor are realized any in the claims 1 to 6 when executing the computer program
Method described in；
The Digitization Software radio platforms are used to export the audio signal after noise elimination processing and frequency discrimination.
9. system according to claim 8, which is characterized in that the system also includes sequentially connected preposition amplification moulds
Block, mixing and filtering module and if sampling module；
The pre-amplifying module is connect with the delivery outlet of the FM signal；The if sampling module and the digital soft
Part radio platforms connection, for exporting the corresponding if sampling of the FM signal to the Digitization Software radio platforms
Data.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810033697.0A CN108155913B (en) | 2018-01-12 | 2018-01-12 | FM signal squelch method, apparatus and system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810033697.0A CN108155913B (en) | 2018-01-12 | 2018-01-12 | FM signal squelch method, apparatus and system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN108155913A CN108155913A (en) | 2018-06-12 |
| CN108155913B true CN108155913B (en) | 2019-11-15 |
Family
ID=62461265
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201810033697.0A Active CN108155913B (en) | 2018-01-12 | 2018-01-12 | FM signal squelch method, apparatus and system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN108155913B (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111294123B (en) * | 2019-04-12 | 2022-03-29 | 展讯通信（上海）有限公司 | FM signal noise processing method and device, storage medium and FM receiver |
| CN111294304B (en) * | 2019-04-12 | 2022-06-14 | 展讯通信（上海）有限公司 | Frequency modulation signal processing method and device, storage medium and frequency modulation receiver |
| CN111294124B (en) * | 2019-04-12 | 2022-06-14 | 展讯通信（上海）有限公司 | Method and device for detecting quality of frequency modulation signal, storage medium and frequency modulation receiver |
| CN110932750A (en) * | 2019-11-04 | 2020-03-27 | 西安极蜂天下信息科技有限公司 | Squelch grade switching method and device |
| CN114520988B (en) * | 2021-12-21 | 2024-01-12 | 海能达通信股份有限公司 | Squelch control method, device, equipment and readable storage medium |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4236335B2 (en) * | 1999-06-03 | 2009-03-11 | 株式会社オーディオテクニカ | Wireless microphone receiver |
| JP4349865B2 (en) * | 2003-08-29 | 2009-10-21 | 三洋電機株式会社 | AM receiver circuit |
| CN102868369B (en) * | 2011-07-05 | 2015-05-13 | 杭州中科微电子有限公司 | Radio frequency automatic gain control amplifier |
| CN202918303U (en) * | 2012-11-02 | 2013-05-01 | 丽水市广播电视总台 | Frequency modulation broadcasting signal receiving and measuring system |
| CN103023852B (en) * | 2012-12-26 | 2015-02-18 | 东南大学 | Fast digital automatic gain control method for orthogonal frequency division multiplexing receiver |
| CN105429656B (en) * | 2015-10-20 | 2018-11-20 | 广州海格通信集团股份有限公司 | The signal processing apparatus of demodulation front end is received based on short wave bandwidth |
-
2018
- 2018-01-12 CN CN201810033697.0A patent/CN108155913B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN108155913A (en) | 2018-06-12 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN108155913B (en) | FM signal squelch method, apparatus and system | |
| CN107645283A (en) | A kind of auto gain control method and device | |
| CN110365302B (en) | Automatic gain control method and device for communication system | |
| CN109756240B (en) | Wireless communication receiver with gain control device and gain control method | |
| US20180048405A1 (en) | Semiconductor device, radio communication device, and control method for radio communication device | |
| JP2004523147A (en) | Wireless receiver | |
| JP5765120B2 (en) | Wireless communication terminal and automatic gain control method | |
| US7187915B2 (en) | Automatic gain control for a WLAN system | |
| CN101730210A (en) | Method and device for calibrating downlink radio frequency | |
| KR101082632B1 (en) | Methods and apparatus for power measurement in a communication system | |
| CN102111194B (en) | Method and device for realizing simulated automatic gain control | |
| JP2005210261A (en) | Wireless communication system and high frequency ic | |
| US11405813B2 (en) | Radio link monitoring (RLM) procedures in new radio unlicensed bands (NR-U) | |
| CN103684496A (en) | Receiver of digital interphone and signal processing method of receiver | |
| CN110855305B (en) | Intermediate frequency digital automatic gain control method and system | |
| CN100440741C (en) | Automatic gain control device and method for mobile communication terminal | |
| CN102082750B (en) | Method and device for eliminating direct current bias | |
| CN113497633B (en) | Method for improving IP2 index of zero intermediate frequency and low intermediate frequency architecture receiver and architecture thereof | |
| US11140636B1 (en) | Roaming method based on MESH WIFI, electronic device and computer program product | |
| US11115072B2 (en) | Interference processing method and apparatus | |
| CN114465681A (en) | Multi-node cooperative spectrum sensing method and device for power Internet of things | |
| KR20160100790A (en) | Method and system for automatic gain control in wireless receiver | |
| US12015438B2 (en) | Smart antenna switching method, electronic device and computer readable storage medium | |
| CN115001603A (en) | Sensitivity detection method, device, medium, circuit, equipment and system | |
| CN114785434B (en) | Method, device, equipment, system and medium for detecting availability of S-band channel |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |