CN111294123A - FM signal noise processing method and device, storage medium and FM receiver - Google Patents
FM signal noise processing method and device, storage medium and FM receiver Download PDFInfo
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Abstract
A frequency modulation signal noise processing method and device, a storage medium and a frequency modulation receiver are provided, wherein the frequency modulation signal noise processing method comprises the following steps: receiving a frequency modulation signal in the current unit time; detecting the signal quality of the frequency-modulated signal; and if the signal quality of the frequency modulation signal is less than a preset threshold, determining that the currently played audio signal is comfort noise with the amplitude less than the preset threshold, or the played signal in the last unit time. The technical scheme of the invention can eliminate the noise in the frequency modulation signal so as to improve the communication quality.
Description
Technical Field
The invention relates to the technical field of signal processing, in particular to a frequency modulation signal noise processing method and device, a storage medium and a frequency modulation receiver.
Background
The Frequency Modulation system includes a conventional analog Frequency Modulation (FM) system and a digital Frequency Shift Keying (FSK) system, and is generally used for short data or voice communication, and the Frequency Modulation system generally adopts a digital Frequency discrimination demodulation method.
At present, the receiver of the narrow-band frequency modulation mode is generally used for civil communication of free public frequency bands. For example, in China, most of the devices work in a 400MHz free public frequency band. For a free public frequency band, various interferences generally cause high background noise in the frequency band, and the interference level often fluctuates greatly.
However, due to sudden interference or sudden signal fluctuation, a speech signal demodulated by a current demodulation frame corresponding to an analog FM system or a digital FSK system may suddenly generate harsh "papa" noise, which may seriously affect the product experience of the user.
Disclosure of Invention
The invention solves the technical problem of how to eliminate the noise in the frequency modulation signal so as to improve the communication quality.
To solve the foregoing technical problem, an embodiment of the present invention provides a method for processing noise of a frequency modulated signal, where the method for processing noise of a frequency modulated signal includes: receiving a frequency modulation signal in the current unit time; detecting the signal quality of the frequency-modulated signal; and if the signal quality of the frequency modulation signal is less than a preset threshold, determining that the currently played audio signal is comfort noise with the amplitude less than the preset threshold, or the played signal in the last unit time.
Optionally, the frequency modulation signal noise processing method further includes: and if the signal quality of the frequency modulation signals in the unit time of the continuous preset number is less than the preset threshold, determining that the currently played audio signal is the comfortable noise.
Optionally, the frequency modulation signal noise processing method further includes: and if the signal quality of the frequency modulation signal reaches the preset threshold, determining that the currently played audio signal is the frequency modulation signal.
Optionally, the frequency modulation signal noise processing method further includes: and storing the frequency modulation signal for being modulated and used as a playing signal in the subsequent unit time.
Optionally, detecting the signal quality of the frequency-modulated signal includes: determining the maximum limit frequency offset of the frequency modulation signal, and determining a frequency offset peak value at least according to the maximum limit frequency offset; determining a digital frequency discrimination output result of the frequency modulation signal, wherein the digital frequency discrimination output result comprises an instantaneous frequency offset; comparing the digital frequency discrimination output result with the frequency deviation peak value to obtain a first quantity, and/or calculating the average frequency deviation in the current unit time according to the digital frequency discrimination output result, wherein the first quantity is the quantity of instant frequency deviations when the frequency deviation reaches the frequency deviation peak value; and determining the signal quality of the frequency modulation signal according to the first quantity and a preset mapping relation, and/or the average frequency offset and the preset mapping relation, wherein the preset mapping relation comprises the signal quality of each grade and the corresponding first quantity thereof, and/or the signal quality of each grade and the corresponding average frequency offset thereof.
Optionally, the preset mapping relationship includes signal qualities of various levels and first quantities corresponding to the signal qualities, and the determining the signal quality of the frequency modulation signal according to the first quantities includes: matching the first quantity with each first quantity in the preset mapping relation; and if the first number of matches exists, taking the signal quality corresponding to the first number of matches as the signal quality of the frequency modulation signal.
Optionally, the preset mapping relationship includes signal quality of each level and an average frequency offset corresponding to the signal quality, and the determining the signal quality of the frequency modulation signal according to the average frequency offset and the preset mapping relationship includes: matching the average frequency deviation with each average frequency deviation in the preset mapping relation; and if the matched average frequency offset exists, taking the signal quality corresponding to the matched average frequency offset as the signal quality of the frequency modulation signal.
Optionally, the determining the signal quality of the frequency modulation signal according to the first number, the preset mapping relationship, the average frequency offset and the preset mapping relationship includes: judging whether the average frequency deviation falls into a preset range or not; if the average frequency offset falls into the preset range, matching the first quantity with each first quantity in the preset mapping relation, and determining the signal quality corresponding to the matched first quantity as the signal quality of the frequency modulation signal;
if the average frequency deviation is lower than the lower limit value of the preset range, determining that the frequency modulation signal is an interference signal of other systems; and if the average frequency offset is higher than the upper limit value of the preset range, determining that the frequency modulation signal is noise or an interference signal of other systems.
Optionally, the modulation system of the frequency modulation signal is digital frequency shift keying, the preset range includes a numerical range between a minimum value of the average frequency offset and a maximum value of the first average frequency offset, and the determining whether the average frequency offset falls into the preset range includes: and judging whether the average frequency deviation is larger than the average frequency deviation minimum value and smaller than the first average frequency deviation maximum value.
Optionally, the modulation format of the frequency modulation signal is analog frequency modulation, the preset range includes a numerical range smaller than a second average frequency offset maximum value, and the determining whether the average frequency offset falls into the preset range includes: and judging whether the average frequency offset is smaller than the second average frequency offset maximum value or not.
In order to solve the above technical problem, an embodiment of the present invention further discloses a frequency modulation signal noise processing apparatus, including: the receiving module is suitable for receiving the frequency modulation signal in the current unit time; the signal quality detection module is suitable for detecting the signal quality of the frequency modulation signal; and the signal playing module is suitable for determining that the currently played audio signal is comfortable noise with amplitude smaller than a preset threshold value or a playing signal in the last unit time when the signal quality of the frequency modulation signal is smaller than the preset threshold value.
The embodiment of the invention also discloses a storage medium, wherein computer instructions are stored on the storage medium, and the steps of the frequency modulation signal noise processing method are executed when the computer instructions are operated.
The embodiment of the invention also discloses a frequency modulation receiver which comprises a memory and a processor, wherein the memory is stored with a computer instruction which can be operated on the processor, and the processor executes the steps of the frequency modulation signal noise processing method when operating the computer instruction.
Compared with the prior art, the technical scheme of the embodiment of the invention has the following beneficial effects:
according to the technical scheme, after receiving the frequency modulation signal in the current unit time, firstly, the signal quality of the frequency modulation signal is detected, and whether the frequency modulation signal generates noise or not can be determined through the signal quality; when the signal quality of the frequency modulation signal is smaller than a preset threshold, the frequency modulation signal is demodulated to generate noise, and under the condition, the currently played audio signal can be determined to be comfortable noise with the amplitude smaller than the preset threshold or the played signal in the last unit time, so that the noise generated by the mistaken playing noise is avoided, and the call quality is improved.
Further, if the signal quality of the frequency modulation signals in the unit time of the continuous preset number is less than the preset threshold, the currently played audio signal is determined to be the comfort noise. In the technical scheme of the invention, if the signal quality of the frequency modulation signal is poor within a continuous period of time, comfortable noise with the amplitude smaller than the preset threshold can be played, so that the same frequency modulation signal is prevented from being played repeatedly, the smoothness of signal playing of the frequency modulation receiver is ensured, and the user experience is improved.
Further, in the technical solution of the present invention, a preset mapping relationship may be preset, where the preset mapping relationship may represent a corresponding relationship between signal quality of each level and average frequency offset in unit time, or may also represent a corresponding relationship between signal quality of each level and the number of instantaneous frequency offsets at which frequency offsets reach a peak frequency offset. Therefore, the signal quality of the frequency modulation signal can be determined by determining the number of instantaneous frequency offsets when the frequency offset of the received frequency modulation signal reaches the peak frequency offset after digital frequency discrimination, or determining the average frequency offset in unit time, so that the situation that the signal and the background noise cannot be distinguished under the condition that an interference signal exists by adopting a signal receiving level judging mode is avoided, and the accuracy of detecting the frequency modulation signal quality is improved.
Drawings
Fig. 1 is a flow chart of a method for processing noise of a frequency modulated signal according to an embodiment of the present invention;
FIG. 2 is a flowchart of one embodiment of step S102 shown in FIG. 1;
FIG. 3 is a flowchart of one embodiment of step S204 shown in FIG. 2;
FIG. 4 is a flowchart of another embodiment of step S204 shown in FIG. 2;
FIG. 5 is a flowchart of yet another embodiment of step S204 shown in FIG. 2;
fig. 6 is a schematic structural diagram of a device for processing noise of a frequency modulated signal according to an embodiment of the present invention.
Detailed Description
As described in the background art, due to sudden interference or sudden signal fluctuation, a speech signal demodulated by a current demodulation frame corresponding to an analog FM system or a digital FSK system may generate a sudden harsh "snap" noise, which seriously affects the product experience of a user.
According to the technical scheme, after receiving the frequency modulation signal in the current unit time, firstly, the signal quality of the frequency modulation signal is detected, and whether the frequency modulation signal generates noise or not can be determined through the signal quality; when the signal quality of the frequency modulation signal is smaller than a preset threshold, the frequency modulation signal is demodulated to generate noise, and under the condition, the currently played audio signal can be determined to be comfortable noise with the amplitude smaller than the preset threshold or the played signal in the last unit time, so that the noise generated by the mistaken playing noise is avoided, and the call quality is improved.
In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below.
Fig. 1 is a flowchart of a method for processing noise of a frequency modulated signal according to an embodiment of the present invention.
The frequency modulation signal noise processing method can be used on the side of a frequency modulation receiver. That is, the various steps shown in fig. 1 may be performed by a fm receiver.
The method for processing the noise of the frequency modulation signal shown in fig. 1 may include the following steps:
step S101: receiving a frequency modulation signal in the current unit time;
step S102: detecting the signal quality of the frequency-modulated signal;
step S103: and if the signal quality of the frequency modulation signal is less than a preset threshold, determining that the currently played audio signal is comfort noise with the amplitude less than the preset threshold, or the played signal in the last unit time.
It should be noted that the sequence numbers of the steps in this embodiment do not represent a limitation on the execution sequence of the steps.
The embodiment of the invention receives and processes the frequency modulation signal according to the time length as unit time. The Frequency Modulation signal may be an analog Frequency Modulation (FM) signal or a digital Frequency-shift keying (FSK) signal.
It should be noted that the frequency modulation signal may also be a frequency modulation signal of any other implementable standard, which is not limited in this embodiment of the present invention. The length of the unit time may be set differently according to the actual application requirement, for example, 30 milliseconds (ms) or 20ms, which is not limited by the embodiment of the present invention.
In the specific implementation of step S101, the fm receiver may receive the fm signal in the current unit time, that is, may receive the fm signal with the time length being the unit time.
Further, in the implementation of step S102, the signal quality of the received fm signal in the current unit time may be detected.
In this embodiment, the Signal quality may be represented by a Signal to interference plus Noise Ratio (SINR). In other words, the signal quality of the frequency modulated signal can be detected by detecting the SINR of the frequency modulated signal. For example, when the frequency modulation signal is a 4FSK signal and SINR > is 9dB, the received FSK signal is considered to be good; when the SINR is between 3dB and 6dB, the quality of the received FSK signal is considered to be general and is near the sensitivity; when the SINR is between 0dB and 3dB, the received FSK signal is considered to be poor, and the demodulated voice signal has a large amount of noise or deformation and may not be understood; when the SINR is between-3 dB and 0dB, the received FSK signal is considered to be very poor and cannot be synchronously received; SINR < -3dB, the received FM signal is considered to be possibly completely noise or interference signal.
It can be understood by those skilled in the art that the criterion for determining the signal quality of the frequency modulated signal may refer to the prior art, for example, the higher the SINR, the higher the signal quality, and the embodiment of the present invention is not limited thereto.
It should be noted that the signal quality in the embodiment of the present invention may be expressed by a specific value, or may be expressed by a range of values, for example, the signal quality is 0dB, or the signal quality is 0-3 dB.
In the following embodiments, a technical solution of representing the signal quality by using the first number and the average frequency offset in the unit time is also described, for example, the lower the first number is, the higher the signal quality is; the average frequency offset is greater than the preset maximum average frequency offset value, and is considered as noise, which is not described herein again.
After the signal quality of the fm signal is determined, in a specific implementation of step S103, the signal quality of the fm signal being less than the preset threshold indicates that the signal quality of the fm signal is poor, in which case, it may be determined that the currently played audio signal is comfort noise with an amplitude less than the preset threshold, or a played signal in the last unit time.
Specifically, when the signal quality of the frequency modulation signal is good, it can be determined that the demodulation of the frequency modulation signal does not generate noise, and at this time, it can be determined that the currently played audio signal is the frequency modulation signal. When the signal quality of the frequency modulation signal is poor, the fact that more noise exists in the frequency modulation signal can be determined, noise can be generated by demodulating the frequency modulation signal, and the demodulated signal can not be played.
In order to ensure the call quality, the comfort noise with the amplitude less than the preset threshold value or the playing signal in the last unit time can be played without playing the demodulation signal.
In a specific embodiment, the playing signal in the previous unit time may be a frequency modulated signal received in the previous unit time, or may be comfort noise with an amplitude smaller than a preset threshold, or may be a frequency modulated signal received in the previous unit time.
In the embodiment of the invention, after receiving the frequency modulation signal in the current unit time, firstly, the signal quality of the frequency modulation signal is detected, and whether the frequency modulation signal generates noise or not can be determined through the signal quality; when the signal quality of the frequency modulation signal is smaller than a preset threshold, the frequency modulation signal is demodulated to generate noise, and under the condition, the currently played audio signal can be determined to be comfortable noise with the amplitude smaller than the preset threshold or the played signal in the last unit time, so that the noise generated by the mistaken playing noise is avoided, and the call quality is improved.
In one non-limiting embodiment, the method shown in FIG. 1 may further include the steps of: and if the signal quality of the frequency modulation signals in the unit time of the continuous preset number is less than the preset threshold, determining that the currently played audio signal is the comfortable noise.
In this embodiment, if the signal quality of the frequency modulation signals in the unit time of the continuous preset number is less than the preset threshold, it indicates that the signal quality of the frequency modulation signals in a continuous period of time is poor.
At the moment, the comfortable noise with the amplitude smaller than the preset threshold value can be played, so that the same frequency modulation signal is prevented from being played repeatedly, the smoothness of signal playing of the frequency modulation receiver is guaranteed, and the user experience is improved.
In one non-limiting embodiment, the method shown in FIG. 1 may further include the steps of: and if the signal quality of the frequency modulation signal reaches the preset threshold, determining that the currently played audio signal is the frequency modulation signal.
In the embodiments of the present invention, the term "to" may mean not less than that.
In this embodiment, if the signal quality of the frequency modulation signal reaches the preset threshold, it indicates that the received frequency modulation signal quality in the current unit time is better. At this point, the FM signal may be played.
Furthermore, the frequency modulation signal can be stored for being modulated and used as a playing signal in the subsequent unit time.
In this embodiment, the audio signal demodulated by the frequency modulation signal may be stored when the signal quality of the frequency modulation signal reaches the preset threshold. That is, in case the signal quality of the frequency modulated signal is good, the frequency modulated signal may be stored, for example in a memory. And when the quality of the received frequency modulation signal in the subsequent unit time is poor, the audio signal can be called from the memory so as to play the audio signal as the currently played audio signal.
In a specific application scenario, the unit time is a data frame, and the time length of the data frame is 20 milliseconds. And receiving the frequency modulation signal in the current data frame T, and detecting to obtain the signal quality of the frequency modulation signal. If the signal quality is still available, performing vocoder decoding on the data in the current data frame T and playing the data; otherwise, the signal quality is considered to be poor, and the audio signal demodulated by the data in the current data frame T is not decoded and played, but the audio signal in the data frame is repeatedly played or the comfort noise is played. The frequency modulated signal in the next data frame is received.
In a non-limiting embodiment, referring to fig. 2, step S102 shown in fig. 1 may include the following steps:
step S201: determining the maximum limit frequency offset of the frequency modulation signal, and determining a frequency offset peak value at least according to the maximum limit frequency offset;
step S202: determining a digital frequency discrimination output result of the frequency modulation signal, wherein the digital frequency discrimination output result comprises an instantaneous frequency offset;
step S203: comparing the digital frequency discrimination output result with the frequency deviation peak value to obtain a first quantity, and/or calculating the average frequency deviation in unit time according to the digital frequency discrimination output result, wherein the first quantity is the quantity of instant frequency deviations when the frequency deviation reaches the frequency deviation peak value;
step S204: and determining the signal quality of the frequency modulation signal according to the first quantity and a preset mapping relation, and/or the average frequency offset and the preset mapping relation, wherein the preset mapping relation comprises the signal quality of each grade and the corresponding first quantity thereof, and/or the signal quality of each grade and the corresponding average frequency offset thereof.
In an implementation of step S201, after receiving the frequency modulated signal, a maximum limit frequency offset of the frequency modulated signal may be determined. The frequency modulation method can be determined by parameters such as the frequency modulation system of the frequency modulation signal, the bandwidth of the transmission frequency modulation signal and the like.
In a specific example, taking an interphone as an example, according to the national standard GB12192, the signal bandwidth of the interphone can be divided into two types, 12.5kHz and 25kHz, the 12.5kHz signal must satisfy the narrow-band (8K5F3E) limit, the 25kHz signal must satisfy the wide-band (16K0F3E) limit, and the Adjacent Channel Power (Adjacent Channel Power) requirement of 60dBc is satisfied, so that the frequency offset of the interphone frequency modulated signal of the signal with the 12.5kHz bandwidth needs to be limited to be within 4kHz at maximum, and the frequency offset of the interphone frequency modulated signal of the signal with the 25kHz bandwidth needs to be limited to be within 8kHz at maximum. That is, the maximum frequency deviation limit of the frequency modulation signal with the signal bandwidth of 12.5kHz is 4kHz, and the maximum frequency deviation limit of the frequency modulation signal with the signal bandwidth of 25kHz is 8 kHz.
When determining the peak frequency offset, the peak frequency offset may be determined only according to the maximum limit frequency offset, and specifically, the frequency offset higher than the preset value of the maximum limit frequency offset may be determined as the peak frequency offset. If the maximum limited frequency offset is 8KHz, the peak frequency offset may be 9 KHz. Or, the peak frequency offset may be determined according to the maximum limit frequency offset and an SINR corresponding to a receiving sensitivity of the fm receiver, specifically, the setting of the peak frequency offset should be greater than the maximum limit frequency offset, and after the set peak frequency offset, the SINR and the first quantity corresponding relation can cover the SINR corresponding to the receiving sensitivity. For example, in table 1 below, if the maximum limited frequency offset is 3KHz and the receiving sensitivity is SINR 0dB, then the first amount corresponding to the sensitivity SINR is 15, and the peak frequency offset may be 10 KHz.
In one implementation of step S202, the frequency-modulated signal received in the current unit time may be digitally frequency-discriminated to obtain a digital frequency-discriminated output result. The digital frequency discrimination output result comprises instantaneous frequency deviation of the frequency modulation signal in unit time, and the number of the instantaneous frequency deviation in unit time is more than 0.
Further, in the implementation of step S203, the digital frequency discrimination output result may be compared with the peak frequency offset to obtain a first quantity. Specifically, by comparing the instantaneous frequency offset in the digital frequency discrimination output result with the peak frequency offset, the magnitude relationship between the instantaneous frequency offset and the peak frequency offset can be determined, so that the number of the instantaneous frequency offsets, that is, the first number, of which the frequency offsets reach the peak frequency offset can be calculated.
In the implementation of step S203, the average frequency offset per unit time may also be calculated according to the digital frequency discrimination output result. Specifically, an average value of all instantaneous frequency offsets in the digital frequency discrimination output result per unit time may be calculated as the average frequency offset.
In this embodiment, in an actual wireless receiving environment, due to interference and noise, a large number of spurs (or referred to as noise signals) far larger than a maximum frequency offset (also called a peak frequency offset) designed by a system may appear in a frequency modulation signal after digital frequency discrimination, or an average frequency offset value is far larger than a designed frequency average value, where the number of spurs and an SINR of the signal are in an inverse relationship, and since neither an FM signal nor an FSK signal before synchronization is achieved can measure an SINR, the reception quality of the signal may be estimated by counting the number of spurs and the average frequency offset value in a unit time.
Further, in the specific implementation of step S204, the signal quality of the frequency modulation signal is determined according to the first number and a preset mapping relationship, and/or the average frequency offset and a preset mapping relationship.
The preset mapping relationship may be preset, and the preset mapping relationship includes signal quality of each level and a first quantity corresponding to the signal quality, and/or signal quality of each level and an average frequency offset corresponding to the signal quality.
Table 1 may be referred to for specific preset mapping relationships. The signal quality is represented by SINR, the peak frequency offset is 10KHz, and the first quantity represents the quantity of instantaneous frequency offsets of which the frequency offsets are larger than 10KHz in unit time.
TABLE 1
| SINR(dB) | A first amount | Average frequency deviation (Hz) |
| 30 | 0 | 4517 |
| 9 | 0 | 4755 |
| 6 | 0 | 4906 |
| 3 | 4 | 5219 |
| 0 | 15 | 5800 |
| -3 | 27 | 6429 |
| White noise | 45 | 7610 |
As shown in table 1, when the SINR is 30dB, the corresponding first quantity is 0, and the corresponding average frequency offset is 4517 Hz; the SINR is 3dB, which corresponds to an average frequency offset of 5219 Hz.
In specific implementation, the preset mapping relationship may be obtained through algorithm simulation or actual measurement using an instrument. Specifically, for a digital FSK signal, since the frequency offset of each modulation symbol is fixed, the algorithm simulates or actually measures to obtain the first number and the average frequency offset at different SINRs in unit time.
It should be noted that the SINR range and the peak frequency offset to be measured may be determined as required. Taking digital modulation as an example, if the SINR range to be measured is greater than 9dB, 9dB to-3 dB and less than-3 dB, the peak frequency offset can be selected to be 4 kHz; if the SINR range to be measured is more than 3dB, 3dB to-3 dB and less than-3 dB, the peak frequency offset can be 10 kHz. Taking an analog interphone with a signal bandwidth of 25kHz as an example, the maximum limit frequency offset of transmission is 8kHz, the peak frequency offset can be 16kHz, and the SINR range to be measured can be more than 5dB, 5dB to-5 dB and less than-5 dB.
In a non-limiting embodiment of the present invention, referring to fig. 3, step S204 shown in fig. 2 may include the following steps:
step S301: matching the first quantity with each first quantity in the preset mapping relation;
step S302: and if the first number of matches exists, taking the signal quality corresponding to the first number of matches as the signal quality of the frequency modulation signal.
In a specific implementation, the first number of matches refers to a first number in a preset mapping relation equal to the first number corresponding to the frequency modulation signal, or a range defined by two first numbers in a preset mapping relation including the first number corresponding to the frequency modulation signal. For example, referring to Table 1, if the first number of FM signals is 10, the first number in Table 1 matching the first number 10 defines a range of 4-15, and the signal quality of the FM signals is 0-3 dB.
In this embodiment, the signal quality of the frequency modulation signal may be determined only according to the first quantity and the preset mapping relationship.
For example, referring to table 2, if the first number is equal to or less than 4, it may be determined that the SINR is equal to or greater than 9dB, and thus it may be determined that the received frequency modulated signal is better.
Furthermore, in the embodiment of step S103 shown in fig. 1, the currently played audio signal may be determined according to the first number.
Specifically, if the first number is greater than a first threshold, it may be determined that the currently played audio signal is comfort noise having an amplitude less than a preset threshold or a played signal in a last unit time.
In a non-limiting embodiment of the present invention, referring to fig. 4, step S204 shown in fig. 2 may include the following steps:
step S401: matching the average frequency deviation with each average frequency deviation in the preset mapping relation;
step S402: and if the matched average frequency offset exists, taking the signal quality corresponding to the matched average frequency offset as the signal quality of the frequency modulation signal.
In a specific implementation, the matched average frequency offset is an average frequency offset in a preset mapping relation equal to the average frequency offset corresponding to the frequency modulation signal, or a range defined by two average frequency offsets in a preset mapping relation including the average frequency offset corresponding to the frequency modulation signal. For example, referring to table 1, when the average frequency offset of the frequency modulated signal is 5500Hz, the range of the average frequency offset in table 1 matching with the average frequency offset 5500 is 5219-5800Hz, and the signal quality of the frequency modulated signal is 0-3 dB.
Different from the foregoing embodiment, the embodiment of the present invention may determine the signal quality of the frequency modulation signal only according to the average frequency offset and the preset mapping relationship.
For example, referring to table 2, if the average frequency offset is greater than 6500Hz, it may be determined that the frequency modulated signal is a noise signal, i.e., the frequency modulated signal has poor signal quality.
Furthermore, in the specific implementation of step S103 shown in fig. 1, the currently played audio signal may be determined according to the average frequency offset.
Specifically, if the average frequency offset is greater than the second threshold, it may be determined that the currently played audio signal is comfort noise with an amplitude less than a preset threshold or a played signal in the last unit time.
In a non-limiting embodiment of the present invention, referring to fig. 5, step S204 shown in fig. 2 may include the following steps:
step S501: judging whether the average frequency deviation falls into a preset range or not;
step S502: if the average frequency offset falls into the preset range, matching the first quantity with each first quantity in the preset mapping relation, and determining the signal quality corresponding to the matched first quantity as the signal quality of the frequency modulation signal;
step S503: if the average frequency deviation is lower than the lower limit value of the preset range, determining that the frequency modulation signal is an interference signal of other systems;
step S504: and if the average frequency offset is higher than the upper limit value of the preset range, determining that the frequency modulation signal is noise or an interference signal of other systems.
When the average frequency offset is lower than the lower limit value of the preset range, the interference signals of other systems can be frequency modulation signals or single-tone signals; when the average Frequency offset is higher than the upper limit value of the preset range, the interference signal of the other system may be an Orthogonal Frequency Division Multiplexing (OFDM) symbol or the like.
Different from the foregoing embodiment, in the embodiment of the present invention, the signal quality of the frequency modulation signal may be determined according to the average frequency offset and the preset mapping relationship between the first quantity and the preset value.
In a specific implementation, different preset ranges may be set for different frequency modulation signals, which is not limited in the embodiment of the present invention.
The embodiment of the invention combines the first quantity and the average frequency offset to determine the signal quality of the frequency modulation signal, thereby ensuring the reliability of signal quality determination.
Further, when the modulation system of the frequency modulation signal is digital frequency shift keying, the preset range includes a numerical range between the minimum average frequency offset and the maximum first average frequency offset. Step S401 shown in fig. 4 may include the steps of: and judging whether the average frequency deviation is larger than the average frequency deviation minimum value and smaller than the first average frequency deviation maximum value.
In this embodiment, the minimum value of the average frequency offset and the maximum value of the first average frequency offset may be set for the FSK signal.
In one particular application scenario, the peak frequency offset is 4K Hz. The minimum value of the average frequency offset may be 2000Hz and the first maximum value of the average frequency offset may be 6500 Hz. It is determined whether the average frequency offset freq _ AveOffset is greater than 2000Hz and less than 6500Hz, and if so, the frequency modulated signal may be determined to be a 4FSK signal, and the signal quality may be determined in combination with the first quantity. If not, and the average frequency offset freq _ AveOffset is less than 2000Hz, and the first number is less than or equal to 92, then it may be determined that the frequency modulated signal may be other non-4 FSK frequency modulated signals, and reception of the frequency modulated signal may be interrupted directly, otherwise it may be determined that the frequency modulated signal is a noise or interference signal, and reception of the frequency modulated signal may be interrupted directly.
Furthermore, in the specific implementation of step S103 shown in fig. 1, the currently played audio signal may be determined according to the first number and the average frequency offset.
Specifically, if the average frequency offset falls within the preset range and the first number is greater than a first threshold, it may be determined that the currently played audio signal is comfort noise with an amplitude less than a preset threshold or a played signal in a last unit time. If the average frequency offset is lower than the lower limit value of the preset range or the average frequency offset is higher than the upper limit value of the preset range, it may be determined that the currently played audio signal is a comfort noise with an amplitude smaller than a preset threshold or a played signal in a previous unit time.
Further, the modulation system of the frequency modulation signal is analog frequency modulation, the preset range includes a numerical range smaller than the second average frequency offset maximum value, and step S501 shown in fig. 5 may include the following steps: and judging whether the average frequency offset is smaller than the second average frequency offset maximum value or not.
In this embodiment, a second average frequency offset maximum value may be set for the FM signal.
In a specific application scenario, if the average frequency offset of the frequency modulation signal is smaller than the second average frequency offset maximum value, the frequency modulation signal may be determined to be an FM signal; otherwise, the frequency modulated signal may be determined to be a noise or interference signal, i.e., a signal of poor quality.
Referring to fig. 6, an embodiment of the invention further discloses a device 60 for processing noise of frequency modulated signals. The fm signal noise processing apparatus 60 may include a receiving module 601, a signal quality detecting module 602, and a signal playing module 603.
The receiving module 601 is adapted to receive a frequency modulation signal in a current unit time; the signal quality detection module 602 is adapted to detect the signal quality of the frequency modulated signal; the signal playing module 603 is adapted to determine that the currently played audio signal is comfort noise with an amplitude smaller than a preset threshold value, or a playing signal in the last unit time when the signal quality of the frequency modulation signal is smaller than the preset threshold value.
For more details of the operating principle and the operating mode of the frequency modulation signal noise processing apparatus 60, reference may be made to the relevant descriptions in fig. 1 to fig. 5, which are not described herein again.
The embodiment of the invention also discloses a storage medium, wherein computer instructions are stored on the storage medium, and when the computer instructions are operated, the steps of the method shown in the figures 1 to 5 can be executed. The storage medium may include ROM, RAM, magnetic or optical disks, etc. The storage medium may further include a non-volatile memory (non-volatile) or a non-transitory memory (non-transient), and the like.
The embodiment of the invention also discloses a frequency modulation receiver which can comprise a memory and a processor, wherein the memory stores computer instructions capable of running on the processor. The processor, when executing the computer instructions, may perform the steps of the methods shown in fig. 1-5. The fm receiver includes, but is not limited to, an intercom, a radio, and other terminal devices.
Although the present invention is disclosed above, the present invention is not limited thereto. Various changes and modifications may be effected therein by one skilled in the art without departing from the spirit and scope of the invention as defined in the appended claims.
Claims (13)
1. A method for processing noise of a frequency modulated signal, comprising:
receiving a frequency modulation signal in the current unit time;
detecting the signal quality of the frequency-modulated signal;
and if the signal quality of the frequency modulation signal is less than a preset threshold, determining that the currently played audio signal is comfort noise with the amplitude less than the preset threshold, or the played signal in the last unit time.
2. A method of processing a frequency modulated signal noise according to claim 1, further comprising:
and if the signal quality of the frequency modulation signals in the unit time of the continuous preset number is less than the preset threshold, determining that the currently played audio signal is the comfortable noise.
3. A method of processing a frequency modulated signal noise according to claim 1, further comprising:
and if the signal quality of the frequency modulation signal reaches the preset threshold, determining that the currently played audio signal is the frequency modulation signal.
4. A method of processing a frequency modulated signal noise according to claim 3, further comprising:
and storing the frequency modulation signal for being modulated and used as a playing signal in the subsequent unit time.
5. A method of processing a frequency modulated signal noise according to claim 1, wherein detecting the signal quality of the frequency modulated signal comprises:
determining the maximum limit frequency offset of the frequency modulation signal, and determining a frequency offset peak value at least according to the maximum limit frequency offset;
determining a digital frequency discrimination output result of the frequency modulation signal, wherein the digital frequency discrimination output result comprises an instantaneous frequency offset;
comparing the digital frequency discrimination output result with the frequency deviation peak value to obtain a first quantity, and/or calculating the average frequency deviation in the current unit time according to the digital frequency discrimination output result, wherein the first quantity is the quantity of instant frequency deviations when the frequency deviation reaches the frequency deviation peak value;
and determining the signal quality of the frequency modulation signal according to the first quantity and a preset mapping relation, and/or the average frequency offset and the preset mapping relation, wherein the preset mapping relation comprises the signal quality of each grade and the corresponding first quantity thereof, and/or the signal quality of each grade and the corresponding average frequency offset thereof.
6. A method as claimed in claim 5, wherein the predetermined mapping comprises signal qualities of respective levels and corresponding first quantities, and the determining the signal quality of the FM signal according to the first quantities comprises:
matching the first quantity with each first quantity in the preset mapping relation;
and if the first number of matches exists, taking the signal quality corresponding to the first number of matches as the signal quality of the frequency modulation signal.
7. The method of claim 5, wherein the predetermined mapping relationship comprises signal quality of each level and average frequency offset corresponding thereto, and the determining the signal quality of the FM signal according to the average frequency offset and the predetermined mapping relationship comprises:
matching the average frequency deviation with each average frequency deviation in the preset mapping relation;
and if the matched average frequency offset exists, taking the signal quality corresponding to the matched average frequency offset as the signal quality of the frequency modulation signal.
8. The method of claim 5, wherein the predetermined mapping relationship comprises signal quality of each level and average frequency offset corresponding thereto, and the determining the signal quality of the FM signal according to the first quantity and the predetermined mapping relationship and the average frequency offset and the predetermined mapping relationship comprises:
judging whether the average frequency deviation falls into a preset range or not;
if the average frequency offset falls into the preset range, matching the first quantity with each first quantity in the preset mapping relation, and determining the signal quality corresponding to the matched first quantity as the signal quality of the frequency modulation signal;
if the average frequency deviation is lower than the lower limit value of the preset range, determining that the frequency modulation signal is an interference signal of other systems;
and if the average frequency offset is higher than the upper limit value of the preset range, determining that the frequency modulation signal is noise or an interference signal of other systems.
9. A method as claimed in claim 8, wherein the modulation format of the frequency modulated signal is digital frequency shift keying, the predetermined range includes a range of values between a minimum average frequency offset and a maximum average frequency offset, and the determining whether the average frequency offset falls within the predetermined range includes:
and judging whether the average frequency deviation is larger than the average frequency deviation minimum value and smaller than the first average frequency deviation maximum value.
10. A method as claimed in claim 8, wherein the modulation format of the frequency modulated signal is analog frequency modulation, the predetermined range includes a range of values smaller than a second average frequency offset maximum, and the determining whether the average frequency offset falls within the predetermined range includes:
and judging whether the average frequency offset is smaller than the second average frequency offset maximum value or not.
11. A frequency modulated signal noise processing apparatus, comprising:
the receiving module is suitable for receiving the frequency modulation signal in the current unit time;
the signal quality detection module is suitable for detecting the signal quality of the frequency modulation signal;
and the signal playing module is suitable for determining that the currently played audio signal is comfortable noise with amplitude smaller than a preset threshold value or a playing signal in the last unit time when the signal quality of the frequency modulation signal is smaller than the preset threshold value.
12. A storage medium having stored thereon computer instructions, wherein said computer instructions are operable to perform the steps of the method of processing noise in a frequency modulated signal according to any one of claims 1 to 10.
13. A fm receiver comprising a memory and a processor, said memory having stored thereon computer instructions executable on said processor, wherein said processor when executing said computer instructions performs the steps of the method of processing noise in a fm signal according to any of claims 1 to 10.
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20060229751A1 (en) * | 2005-04-04 | 2006-10-12 | Barnhill Matthew S | Signal quality estimation and control system |
| CN102045117A (en) * | 2009-10-19 | 2011-05-04 | 创杰科技股份有限公司 | Apparatus and method for signal quality measurement on gfsk signals |
| CN108155913A (en) * | 2018-01-12 | 2018-06-12 | 福建飞通通讯科技股份有限公司 | FM signal squelch method, apparatus and system |
| CN108449153A (en) * | 2018-03-20 | 2018-08-24 | 深圳市中科汉天下电子有限公司 | A kind of broadcast channel search method and device |
| CN109510636A (en) * | 2018-10-31 | 2019-03-22 | 华勤通讯技术有限公司 | Receive test method, device, medium and the equipment of FM signal function |
-
2019
- 2019-04-12 CN CN201910295946.8A patent/CN111294123B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20060229751A1 (en) * | 2005-04-04 | 2006-10-12 | Barnhill Matthew S | Signal quality estimation and control system |
| CN102045117A (en) * | 2009-10-19 | 2011-05-04 | 创杰科技股份有限公司 | Apparatus and method for signal quality measurement on gfsk signals |
| CN108155913A (en) * | 2018-01-12 | 2018-06-12 | 福建飞通通讯科技股份有限公司 | FM signal squelch method, apparatus and system |
| CN108449153A (en) * | 2018-03-20 | 2018-08-24 | 深圳市中科汉天下电子有限公司 | A kind of broadcast channel search method and device |
| CN109510636A (en) * | 2018-10-31 | 2019-03-22 | 华勤通讯技术有限公司 | Receive test method, device, medium and the equipment of FM signal function |
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