JP2011234292A - Radio device, and operating clock frequency control method for the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To avoid a situation where a beat interference is mistaken for a valid radio signal.SOLUTION: A radio device 100 comprises: a detection part 118 detecting a reception signal in any frequency to generate detection signals; a noise HPF 132 extracting a squelch noise not less than a prescribed frequency in the detection signals; a noise determination part 140 determining whether a voltage of the squelch noise is not less than a prescribed threshold value; a switch 142 suppressing the detection signal if the voltage of the squelch noise is determined to be not less than the prescribed threshold value; and a CPU 200a changing the operating clock frequency of the radio device if the voltage of the squelch noise is determined to be less than the prescribed threshold value, wherein the noise determination part determines whether the voltage of the squelch noise extracted newly by a noise extraction part is not less than the prescribed threshold value, when a frequency control part changes the operation clock frequency.

Description

  The present invention relates to a radio used for radio communication and a method for controlling an operation clock frequency of the radio.

  In a radio using a frequency modulation (FM) system, the internal clock signal of the radio itself wraps around an electrical signal and causes reception interference due to a beat that detects an erroneous signal ( Hereinafter, this is simply referred to as beat interference). For example, when reception is attempted at an arbitrary frequency, beat interference is mistakenly recognized as reception of a radio signal even though a valid radio signal (RF signal) is not received, and squelch (SQL: Squelch) may open. Therefore, the user has to judge himself / herself by listening to the sound output from the speaker whether he / she is receiving a valid radio signal or simply causing a beat disturbance.

  Therefore, at the time of manufacturing, a RSSI (Received Signal Strength Indicator) for each frequency at which a signal is received is detected, and if the RSSI exceeds a predetermined value, it is considered that beat interference has occurred and the clock frequency is shifted. Has been proposed (for example, Patent Document 1).

JP 2006-25049 A

  When attempting to receive a signal using the wireless communication device described in Patent Document 1, since the clock frequency is changed at a frequency at which beat interference occurs, the user determines whether there is an effective wireless signal without being confused by beat interference. can do. However, since the influence of beat interference is confirmed using RSSI, if the signal due to beat interference is at a low level, it is buried in other noise signals and cannot be detected. In this case, when using a radio device, the clock frequency may not be changed appropriately, and the user must also listen to the sound output from the speaker with his / her ear to confirm the presence of a valid radio signal. There wasn't.

  SUMMARY OF THE INVENTION In view of such problems, the present invention has an object to provide a radio and an operation clock frequency control method for the radio that can avoid a situation in which a signal due to beat interference is mistaken as an effective radio signal. Yes.

  In order to solve the above-described problem, the radio of the present invention includes a detection unit that detects a reception signal at an arbitrary frequency to generate a detection signal, and noise extraction that extracts squelch noise of a predetermined frequency or more from the detection signal. A noise determination unit that determines whether or not the squelch noise voltage is greater than or equal to a predetermined threshold, a squelch unit that suppresses the detection signal when the squelch noise voltage is determined to be greater than or equal to the predetermined threshold, A frequency control unit that changes an operation clock frequency of the wireless device when the noise voltage is determined to be less than a predetermined threshold, and the noise determination unit extracts a noise when the frequency control unit changes the operation clock frequency. It is characterized by determining whether the voltage of the squelch noise newly extracted by the unit is equal to or higher than a predetermined threshold value.

  The operation clock frequency may be set independently in the plurality of clock circuits, and the frequency control unit may change the operation clock frequencies of the plurality of clock circuits, respectively.

  When the noise determination unit determines that the voltage of the squelch noise newly extracted by the noise extraction unit is equal to or higher than a predetermined threshold, the wireless device associates the state of the operation clock frequency with an arbitrary frequency. You may further provide the memory | storage part which memorize | stores information.

  In order to solve the above-mentioned problem, the radio operating clock frequency control method of the present invention detects a received signal at an arbitrary frequency to generate a detected signal, and extracts a squelch noise of a predetermined frequency or higher from the detected signal. Then, it is determined whether or not the squelch noise voltage is equal to or higher than a predetermined threshold, and if it is determined that the squelch noise voltage is equal to or higher than the predetermined threshold, the detection signal is suppressed and the squelch noise voltage is lower than the predetermined threshold. When the determination is made, the operation clock frequency of the wireless device is changed, and it is further determined whether or not the voltage of the newly extracted squelch noise is equal to or higher than a predetermined threshold value.

  The wireless device of the present invention can avoid a situation in which beat interference is mistaken as an effective wireless signal. Thus, the user can confirm that a valid radio signal is received without being confused by beat disturbance, or that the frequency can be used for transmission.

It is a functional block diagram showing an electrical configuration of a wireless device in the first embodiment. It is explanatory drawing for demonstrating the detailed structure of a central control part. It is explanatory drawing for demonstrating the detection of the beat disturbance using each of squelch noise and RSSI. It is explanatory drawing which shows the experiment example of the detection of the target signal using each of squelch noise and RSSI. It is explanatory drawing for demonstrating the other structure for switching the operation clock frequency in a central control part. It is a flowchart which shows the flow of a process of the operation clock frequency control method of the radio | wireless machine in 1st Embodiment. It is the functional block diagram which showed the electric constitution of the radio | wireless machine in 2nd Embodiment. 6 is a flowchart illustrating a processing flow of a radio device operation clock frequency control method according to the second embodiment.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The dimensions, materials, and other specific numerical values shown in the embodiments are merely examples for facilitating understanding of the invention, and do not limit the present invention unless otherwise specified. In the present specification and drawings, elements having substantially the same function and configuration are denoted by the same reference numerals, and redundant description is omitted, and elements not directly related to the present invention are not illustrated. To do.

  In an FM radio device, beat interference may occur due to the influence of a clock signal that operates the radio device itself. For this reason, a signal due to beat interference (hereinafter referred to as a beat signal) may be mistaken as an effective radio signal and a squelch may be opened even though an effective radio signal is not received. The user had to determine by listening to the sound output from the speaker with his / her ear whether the signal is being received or whether beat disturbance has just occurred.

  In view of this, a radio device is proposed that can automatically determine the influence of beat interference without the troublesome task of the user confirming with the ear. Hereinafter, the radio device 100 and the radio device 400 will be described in detail by dividing them into the first embodiment and the second embodiment.

(First embodiment: radio device 100)
FIG. 1 is a functional block diagram illustrating an electrical configuration of the wireless device 100. The radio 100 includes an antenna 110, an RF circuit 112, an operation unit 114, a central control unit 116, a detection unit 118, an output amplifier 120, an audio output unit 122, an audio input unit 126, and an input amplifier 128. A noise HPF 132, a noise amplifier 134, a rectifier circuit 136, a smoothing circuit 138, a noise determination unit 140, and a switch 142.

  When a wireless signal such as wireless communication or FM broadcast is received through the antenna 110, the RF circuit 112 receives the received signal at an arbitrary frequency indicated by the central control unit 116 in accordance with a user operation input through the operation unit 114. The signal is extracted, and the detection unit 118 detects (demodulates) the extracted reception signal to generate a detection signal. In the present embodiment, the received signal is a radio signal received through the antenna 110. However, in the RF circuit 112, a radio signal and a signal due to beat interference described later cannot be distinguished from each other, so that a signal due to beat interference is included in the received signal.

  The central control unit 116 includes a plurality of CPUs to be described later and a plurality of clock circuits attached to the respective CPUs, and controls the entire radio device 100 with a control signal calculated based on the clock signal.

  The detection signal generated by the detection unit 118 is amplified by the output amplifier 120 and output to the audio output unit 122 such as a speaker or headphones. The sound output unit 122 outputs sound by vibrating the air in accordance with the detection signal.

  The audio input unit 126 includes a microphone or the like, converts air vibration such as audio into an audio signal, and outputs the audio signal to the RF circuit 112 through the input amplifier 128. The RF circuit 112 modulates a carrier wave corresponding to an arbitrary frequency indicated by the central control unit 116 based on the audio signal amplified and output by the input amplifier 128, generates a transmission signal, and outputs the transmission signal to the antenna 110. The antenna 110 transmits the transmission signal as a radio signal to another radio device or the like.

  The noise HPF 132 functions as a noise extraction unit, and among the detection signals generated by the detection unit 118, a band component (hereinafter simply referred to as squelch noise) that can be regarded as noise having a predetermined frequency (for example, 3 kHz) or higher. .) Is extracted. The squelch noise extracted by the noise HPF 132 is amplified through the noise amplifier 134, rectified by the rectifier circuit 136, and then smoothed by the smoothing circuit 138.

  The noise determination unit 140 determines whether the voltage of the squelch noise smoothed by the smoothing circuit 138 is equal to or higher than a predetermined threshold. The switch 142 functions as a suppression unit. When the voltage of the squelch noise is equal to or higher than a predetermined threshold, the switch 142 determines that a valid radio signal is not received by the radio device 100, and detects the detection signal according to the control signal of the noise determination unit 140. Is suppressed in the present embodiment. Therefore, if the voltage of the squelch noise is equal to or higher than the predetermined threshold, the switch 142 is opened, and the detection signal amplified by the output amplifier 120 is not output to the audio output unit 122. Therefore, the user does not hear unnecessary noise. That's it. Here, the noise determination unit 140 expresses that the switch 142 is in the open state as “close the squelch” and that the switch 142 is in the closed state is expressed as “open the squelch”.

  By the way, as described above, beat interference may occur in the FM radio apparatus 100, so that the beat signal is misidentified as an effective radio signal even though the effective radio signal is not received, and the squelch. Sometimes opened. Therefore, the wireless device 100 according to the present embodiment has a function of avoiding erroneous determination due to beat interference. Hereinafter, the central control unit 116 having such a function will be described.

  FIG. 2 is an explanatory diagram for explaining the central control unit 116. 2A shows an example of connection between the central control unit 116, particularly the CPUs 200a to 200c, and the clock circuits 202a to 202c. FIG. 2B shows ON / OFF of the clock circuits 202a to 202c by the central control unit 116. A control pattern is shown.

  The central control unit 116 includes CPUs 200a to 200c and clock circuits 202a to 202c. The clock circuits 202a to 202c include crystal resonators 204a to 204c, switching transistors 206a to 206c, capacitors 208a to 208c, capacitors 210a to 210c, and capacitors 212a to 212c, respectively. Taking the clock circuit 202a as an example, the base of the switching transistor 206a is connected to the CPU 200a, the collector is connected to the capacitor 212a, and the emitter is grounded. One end of the crystal unit 204a is connected to the capacitors 210a and 212a and the CPU 200a, and the other end is connected to the CPU 200a and the capacitor 208a. The other ends of the capacitors 208a and 210a are grounded.

  The CPU 200a turns on / off the voltage applied to the base of the switching transistor 206a to turn on / off the current between the collector and emitter of the switching transistor 206a, and switches whether to connect the capacitor 212a to the capacitor 210a in parallel. .

  With such a configuration, the CPU 200a can change the operation clock frequency of the clock signal generated by the clock circuit 202a. Similarly, the CPU 200a can change the operation clock frequency of the clock signal generated by the clock circuits 202b and 202c by controlling whether or not to apply a voltage to the bases of the switching transistors 206b and 206c.

  As described above, the CPU 200 (the CPU 200a in the present embodiment) functions as a frequency control unit. When the noise determination unit 140 determines that the squelch noise voltage is less than a predetermined threshold, the CPU 200 sets the operation clock frequency of the radio device 100. change.

  The operation clock frequency of each of the CPUs 200a to 200c varies depending on whether or not a voltage is applied to the bases of the switching transistors 206a to 206c, and the combination is, for example, a pattern number 220 of 0 as shown in FIG. Eight patterns which are ˜7. In FIG. 2B, ON indicates a state in which a voltage is applied to the bases of the switching transistors 206a to 206c, and OFF indicates a state in which no voltage is applied to the bases.

  When the CPU 200a changes the operation clock frequency from any pattern to another pattern, the noise determination unit 140 determines whether the voltage of the squelch noise newly extracted by the noise HPF 132 is equal to or higher than a predetermined threshold. When the noise determination unit 140 determines that the squelch noise voltage is less than the predetermined threshold, the CPU 200a further changes the operation clock frequency of the wireless device 100 to another pattern, and the noise determination unit 140 causes the squelch noise to be reduced. CPU 200a determines that the received signal is a beat signal, and stops changing the operation clock. At this time, the noise determination unit 140 opens the switch 142 (closes the squelch) and blocks the detection signal. In this way, the CPU 200a controls the voltage application state to the bases of the switching transistors 206a to 206c until the squelch noise voltage is determined to be equal to or higher than the predetermined threshold, and sequentially changes the operation clock frequency along the eight patterns. To do. If the squelch noise voltage is less than the predetermined threshold value even after repeating the eight patterns twice, it is assumed that a valid radio signal has been received or beat interference cannot be avoided, and the CPU 200a The number 220 is set to 0, and the change of the operation clock frequency is completed.

  In addition, here, when the noise determination unit 140 determines that the voltage of the squelch noise is equal to or higher than the predetermined threshold, the CPU 200a immediately stops the change of the operation clock to shorten the beat disturbance avoidance process. Even if the squelch noise voltage exceeds a predetermined threshold value, the squelch noise voltage is measured for all the operation clock frequencies of the eight patterns, and the pattern with the highest voltage is selected as the operation clock frequency to avoid beat interference. May be terminated. In this way, the influence of beat disturbance can be minimized.

  Furthermore, here, when the eight patterns are repeated twice, and all the squelch noise voltages are less than the predetermined threshold, it is assumed that there is a valid radio signal, and the change of the operating clock frequency is terminated. The present invention is not limited to this, and beat disturbance avoidance processing may be executed continuously or periodically while staying at the same frequency.

  For example, when the wireless device 100 is receiving a sufficiently strong and effective wireless signal, the squelch noise voltage is equal to or higher than a predetermined threshold even if the above eight patterns are repeated twice (even if the beat interference avoiding process is performed). Therefore, the CPU 200a sets the pattern number 220 to 0 and once ends the change of the operation clock frequency. However, the noise determination unit 140 is executed at the timing when the sufficiently strong and effective radio signal is reduced or lost by continuously or periodically executing the beat disturbance avoidance process thereafter. Can search for a pattern in which the squelch noise voltage is equal to or greater than a predetermined threshold. In this way, beat disturbance buried in a strong received signal can be avoided afterwards.

  As described above, the operation clock frequency is set independently by the plurality of clock circuits 202a to 202c, and the CPU 200a changes the operation clock frequency of the clock signal generated by the plurality of clock circuits 202a to 202c, respectively. Even if each of the radio devices 100 includes a plurality of clock circuits 202a to 202c capable of independently changing the operation clock frequency, the operation clock frequency can be changed only between two values, the clock circuits 202a to 202c A combination pattern of powers of 2 with the number of 202c as an index can be selected, and the probability that the influence of beat disturbance can be avoided can be dramatically increased.

  As described above, the configuration in which the CPU 200a changes the operation clock frequency can automatically determine whether the detection signal at an arbitrary frequency is a valid radio signal or a beat signal. When trying to transmit a radio signal and searching for an available frequency and tuning to an arbitrary frequency, the beat signal was mistakenly recognized as a valid radio signal, or a scan was performed to receive a broadcast FM broadcast, etc. In such a case, it is possible to avoid a situation in which the beat signal is mistaken as a valid radio signal and the scan is stopped.

  By the way, a means for avoiding the influence of beat interference using RSSI can be considered regardless of the squelch noise voltage. However, when the beat signal is at a low level, even if RSSI is used, it may be buried in other noise signals and beat interference may not be detected. Since radio apparatus 100 uses the voltage of squelch noise for confirming the influence of beat disturbance, radio apparatus 100 can reliably detect a smaller signal due to beat disturbance compared to the case of using RSSI. The reason will be described with reference to FIGS.

  FIG. 3 is an explanatory diagram for explaining detection of beat interference using squelch noise and RSSI. In FIG. 3, the horizontal axis represents the signal level, the left vertical axis represents the noise suppression ratio (Noise Rate), and the right vertical axis represents the RSSI.

  The squelch noise (SQL in FIG. 3) is a noise component having a frequency equal to or higher than a predetermined frequency after detection, and this noise component is generated by a noise component before detection. Therefore, the noise component before detection matches the change in the noise suppression ratio. Here, the squelch noise is expressed as a noise suppression ratio, the level of disturbance noise, which is noise caused by beat disturbance and all other disturbances, is N, and a target signal that is a signal to be detected (in this embodiment, a beat signal) ), The squelch noise is expressed by N / (S + N).

  In addition, (S + N) / N is used for RSSI (S / N ratio), and since the range of the signal level is wide, it is usually detected as a logarithmic value and represented by Log ((S + N) / N).

  In FIG. 3, when the noise level is normalized as 1 (N = 1), the change in squelch noise and RSSI when the signal level is changed from 0 to 10,000 can be compared. Since the disturbance noise level is normalized, the relative relationship between the squelch noise and RSSI is as shown in FIG. 3 regardless of the disturbance noise level.

  In squelch noise, for example, when the level of the target signal increases from 0.01 to 0.1, the value of squelch noise changes from 1.0 to 0.9, and the range (approximately 0 to 1.0) Of these, about 10% changed. On the other hand, in RSSI, for example, when the level of the target signal increases from 0.01 to 0.1, the RSSI value does not change from almost 0 and falls within the range (generally 0 to 4.0). On the other hand, it is difficult to set a threshold for grasping such a change.

  In addition, when the target signal is focused on other levels 0.1 to 1, the squelch noise is about 0.5 to 0.9, which is about 40% of the range, and RSSI. There is only a change of less than about 10% of the range, approximately 0.04 to 0.3. From this, it can be seen that if squelch noise is used, the amount of change is large, so that the target signal can be detected with high accuracy. In addition, when the level of the target signal is in the range of about 0.1 to 1, the RSSI is a value near 0 and may be affected by a measurement error or the like, but the squelch noise is relatively high in the range. Since it is detected numerically, the presence / absence of the target signal can be determined with higher accuracy.

  Thus, even if the level of the target signal does not change the RSSI, there is a significant change if it is squelch noise, and it is easy to detect the change. In other words, squelch noise is superior in detecting beat disturbance as compared to RSSI.

  FIG. 4 is an explanatory diagram illustrating an experiment example of target signal detection using squelch noise and RSSI. For example, two VHF (Very High Frequency) bands and two UHF (Ultra High Frequency) bands, each using a radio capable of receiving two waves simultaneously by a combination of VHF and VHF, VHF and UHF, UHF and UHF, are used. The squelch noise (noise suppression ratio) and RSSI were measured while changing the level of the target signal (here, the radio signal). As shown in FIG. 4, when the target signal is at a lower level (for example, −136 dBm to −128 dBm), the measurement result of the squelch noise indicated by the solid line is measured compared to the measurement result of RSSI indicated by the broken line. It can be seen that the voltage value and its change are large and the change can be easily detected.

  As described above, radio apparatus 100 according to the present embodiment uses squelch noise to determine the occurrence of beat disturbance. Therefore, even when the level of the beat signal is low, the beat signal is not easily buried in other disturbance noise, and beats are accurately performed. Misidentification due to interference can be avoided.

  FIG. 5 is an explanatory diagram for explaining another configuration for switching the operation clock frequency in the central control unit 116. As shown in FIG. 5A, the central control unit 116 includes only one set of CPU 200 and a clock circuit 202. The clock circuit 202 includes two or more capacitors 280a to 208d and a crystal resonator 282. Switching transistors 284c and 284d may be provided. With this configuration, the CPU 200 can switch at an operation clock frequency of 4 or more by controlling the application of voltage to the bases of the switching transistors 284c and 284d.

  5B, the central control unit 116 includes a D / A conversion unit 290 in addition to the CPU 200, the clock circuit 202 including the capacitors 280a to 280c, the crystal resonator 282, and the transistor 288. The CPU 200 can change the operating clock frequency linearly by changing the voltage applied to the base of the transistor 288 of the clock circuit 202 through the D / A converter 290 linearly.

  As described above, according to the wireless device 100 of the present embodiment, it is possible to avoid a situation in which a beat signal is mistaken as an effective wireless signal.

(Operation clock frequency control method)
Next, an operation clock frequency control method using the radio device 100 will be described. FIG. 6 is a flowchart illustrating a processing flow of the operation clock frequency control method of the wireless device 100 according to the first embodiment.

  When the frequency at which signals are transmitted and received is changed by the user's operation input through the operation unit 114 (YES in S300), the CPU 200a changes the operation clock frequency so that the pattern number 220 is 0 (S302), and the detection unit 118. Generates a detection signal (S304), and the noise HPF 132 extracts squelch noise (S306). The noise determination unit 140 determines whether or not the squelch noise voltage is less than a predetermined threshold (S308), and if the squelch noise voltage is equal to or higher than the predetermined threshold (NO in S308), no beat interference has occurred, or It is determined that the influence is avoided, and the process returns to the frequency change determination step S300. In frequency change determination step S300, the user waits for a frequency change input (NO in S300).

  When the squelch noise voltage is less than the predetermined threshold value (YES in S308) and the pattern number is not 8 (NO in S310), the CPU 200a adds 1 to the pattern number and operates to the pattern state of the next pattern number. The clock frequency is changed (S312), and the process returns to the detection signal generation step S304.

  If the pattern number is 8 (YES in S310), it is determined whether or not there is a pattern of pattern number 220 that has been tried twice (the second round and the second round flag is set) (S314). If it is not the second round yet (NO in S314), the second round flag indicating the second round is set (S316), and the process returns to the detection signal generation step S304. If it has already been tried once and entered the second lap, that is, if the second week flag is set (YES in S314), the pattern number 220 is set to 0 (S318) and a valid radio signal is received. If it is determined that the influence of the beat disturbance cannot be avoided, the process returns to the frequency change determination step S300.

  As described above, by using the operation clock frequency control method described above, it is possible to avoid a situation in which a beat signal is mistaken as an effective radio signal.

(Second Embodiment)
In the wireless device 100 according to the first embodiment described above, it is possible to avoid the influence of beat interference, but the pattern number 220 (operation clock frequency) that can avoid the influence of beat interference will be used in particular later. I didn't do that. In the second embodiment, a description will be given of a wireless device 400 that can more efficiently avoid the influence of beat interference by using the pattern number 220.

(Radio device 400)
FIG. 7 is a functional block diagram illustrating an electrical configuration of the wireless device 400 according to the second embodiment. As shown in FIG. 7, the radio 400 includes an antenna 110, an RF circuit 112, an operation unit 114, a central control unit 116, a detection unit 118, an output amplifier 120, an audio output unit 122, and an audio input. Unit 126, input amplifier 128, noise HPF 132, noise amplifier 134, rectifier circuit 136, smoothing circuit 138, noise determination unit 140, switch 142, and storage unit 450. The central control unit 116 includes CPUs 200a to 200c and clock circuits 202a to 202c. The antenna 110, the RF circuit 112, the operation unit 114, the central control unit 116, the detection unit 118, the output amplifier 120, and the audio output unit 122 that have already been described as the constituent elements in the first embodiment described above. , An audio input unit 126, an input amplifier 128, a noise HPF 132, a noise amplifier 134, a rectifier circuit 136, a smoothing circuit 138, a noise determination unit 140, a switch 142, CPUs 200a to 200c, and a clock circuit 202a. Since the functions are substantially the same as those of ˜202c, the redundant description is omitted. Here, the storage unit 450 having a different configuration will be mainly described.

  The storage unit 450 includes an HDD (Hard Disk Drive), a flash memory, a nonvolatile RAM (Random Access Memory), etc., and associates one of the pattern numbers 220 indicating the state of the operation clock frequency with the frequency to be transmitted and received, Store as information.

  When the user performs an operation input for new registration or update of clock information through the operation unit 114, the detection unit 118 detects and detects a received signal at each preset frequency or at a preset frequency interval. Generate a signal. When the noise determination unit 140 determines that the voltage of the squelch noise newly extracted by the noise HPF 132 is equal to or greater than a predetermined threshold based on the control command of the central control unit 116, the storage unit 450 determines the pattern number 220 at that time. And the frequency of the received signal when the pattern number 220 is extracted.

  Thereafter, when the user performs tuning, the CPU 200a refers to the clock information stored in the storage unit 450 so as to be in the state of the operation clock frequency indicated by the pattern number 220 associated with the frequency at that time. Controls ON / OFF of voltage application at the bases of the switching transistors 206a to 206c.

  In addition, for example, by setting a predetermined width to the frequency in advance, even if the pattern number 220 is not associated with the frequency set by the user, it is associated with the frequency included in the predetermined width before and after the frequency. If the pattern number 220 is stored, the CPU 200a may change the operation clock frequency using the pattern number 220 as the pattern number 220 of the frequency set by the user.

  As described above, with the configuration including the storage unit 450 that stores the clock information, the frequency stored in the storage unit 450 at the next use is used as the frequency at which the clock information is stored once, unless the environment changes greatly. Therefore, it is possible to determine the presence or absence of an effective radio signal in a short time without requiring the beat disturbance determination process again.

  In addition, when the clock information is newly registered or updated, the central control unit 116 does not squelch noise voltages for all the operation clock frequencies of the eight patterns, but for each frequency, not until the squelch noise voltage exceeds a predetermined threshold. May be measured by the noise determination unit 140 and the pattern having the highest voltage may be stored in the storage unit 450 as clock information. With this configuration, it is possible to store, in the storage unit 450, an operation clock frequency that has the least influence of beat interference among the options.

  In the wireless device 400 described above, once the beat disturbance determination process is executed, the influence of the beat interference of the wireless device 400 does not change. Can be avoided.

(Operation clock frequency control method)
Next, an operation clock frequency control method using the wireless device 400 will be described. FIG. 8 is a flowchart illustrating a processing flow of the operation clock frequency control method of the wireless device 400 according to the second embodiment. In particular, FIG. 8A shows a clock information registration method, and FIG. 8B shows an operation clock frequency control method using the clock information.

  As shown in FIG. 8A, when the user inputs a new registration or update operation of clock information through the operation unit 114 (YES in S500), the central control unit 116, for example, among the preset frequencies, The first frequency is selected (S502). The subsequent processing from the pattern number initial setting step S302 to the pattern number initial regression setting step S318 is substantially the same as the processing described in FIG.

  When the voltage of the squelch noise is equal to or higher than the predetermined threshold in the voltage determination step S308 (NO in S308), or after the pattern number initial regression setting step S318, the central control unit 116 indicates a pattern indicating the state of the operation clock frequency at that time. Clock information indicating the number 220 and the frequency of the received signal when the pattern number 220 is extracted is stored (S504). Then, the central control unit 116 determines whether there is a frequency for which clock information is not yet registered or updated (S506), and when there is a frequency for which clock information has not yet been registered or updated (YES in S506). The next frequency is selected from the preset frequencies (S508), and the process returns to the pattern number initial setting step S302. If there is no frequency for which clock information is not registered or updated (NO in S506), the process returns to the registration operation determination step S500.

  As shown in FIG. 8B, when the frequency at which a signal is transmitted and received is changed by a user operation input through the operation unit 114 (YES in S520), the CPU 200a determines from the clock information stored in the storage unit 450. The clock information including the frequency is extracted (S522), and the CPU 200a changes the operation clock frequency based on the pattern number 220 included in the clock information (S524).

  As described above, in the operation clock frequency control method described above, the clock information when the beat disturbance determination process is executed is stored (FIG. 8A), and the clock information is used later (FIG. 8B). The wireless device 400 can be used in a state where the influence of beat interference is small.

  As mentioned above, although preferred embodiment of this invention was described referring an accompanying drawing, it cannot be overemphasized that this invention is not limited to this embodiment. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the claims, and these are naturally within the technical scope of the present invention. Is done.

  Note that each step of the operation clock frequency control method of this specification does not necessarily have to be processed in time series in the order described in the flowchart, and may include processing in parallel or by a subroutine.

  INDUSTRIAL APPLICABILITY The present invention can be used for a wireless device used for wireless communication and an operation clock frequency control method for the wireless device.

DESCRIPTION OF SYMBOLS 100 ... Radio | wireless machine 118 ... Detection part 132 ... Noise HPF (noise extraction part)
140 ... Noise judgment unit 142 ... Switch (suppression unit)
200a ... CPU (frequency control unit)
202 ... Clock circuit 450 ... Storage section

Claims (4)

A detection unit that detects a reception signal at an arbitrary frequency and generates a detection signal;
A noise extraction unit for extracting squelch noise of a predetermined frequency or more from the detection signal;
A noise determination unit for determining whether the voltage of the squelch noise is equal to or higher than a predetermined threshold;
When it is determined that the voltage of the squelch noise is equal to or higher than the predetermined threshold, a suppression unit that suppresses the detection signal;
When it is determined that the voltage of the squelch noise is less than the predetermined threshold, a frequency control unit that changes an operation clock frequency of the wireless device;
With
The noise determination unit may determine whether a voltage of the squelch noise newly extracted by the noise extraction unit is equal to or higher than the predetermined threshold when the frequency control unit changes the operation clock frequency. transceiver. The operation clock frequency is set independently in a plurality of clock circuits,
The radio device according to claim 1, wherein the frequency control unit changes an operation clock frequency of each of the plurality of clock circuits.   When the noise determination unit determines that the voltage of the squelch noise newly extracted by the noise extraction unit is equal to or higher than the predetermined threshold, the clock information that associates the state of the operation clock frequency at that time with the arbitrary frequency The wireless device according to claim 1, further comprising a storage unit that stores. Generate a detection signal by detecting the received signal at any frequency,
Extracting squelch noise of a predetermined frequency or more from the detection signal,
Determining whether the voltage of the squelch noise is equal to or higher than a predetermined threshold;
When it is determined that the voltage of the squelch noise is not less than the predetermined threshold, the detection signal is suppressed,
If it is determined that the voltage of the squelch noise is less than the predetermined threshold, the operation clock frequency of the radio is changed,
Further, it is determined whether or not the voltage of the newly extracted squelch noise is equal to or higher than the predetermined threshold value.

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