JP2005311913A - Receiving device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a receiving device for informing detail information about a receiving condition of a communication signal. <P>SOLUTION: The receiving device includes a receiving circuit 122 for receiving a communication signal, a receiving control unit 2 for detecting a bit synchronization signal 202 from a communication signal received by the receiving circuit 122, and an LED 4 for informing the receiving condition of the communication signal. In the receiving control unit 2, if the bit synchronization signal 202 is not detected and a signal level of the communication signal measured by a receive intensity measuring unit is over a previously set reference level, the LED 4 is lightened for informing that an fault is caused in consideration that a noise is received by the receiving circuit 122. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a receiving apparatus, and more particularly to a receiving apparatus that can notify a reception state of a communication signal.

  Low-power radio and weak radio are convenient to use without requiring a license, and are applied to various products in the fields of telecontrol, telemeter, and security. As technical standards and technical standards applied to such wireless communication, for example, "ARIB STD-T67 for specifying low power radio station for telemeter, telecontrol and data transmission wireless equipment standard published by the radio wave industry" And “RCR STD-30 Low Power Security System Radio Station Radio Equipment Standard” have been standardized, and the allocation of the occupied frequency band is defined.

  FIG. 9 is a block diagram illustrating a configuration of a transmission apparatus in a low-power radio apparatus according to the background art. A transmission device 100 illustrated in FIG. 9 is a transmission device that wirelessly transmits data detected by a sensor such as a temperature sensor, for example, and includes a sensor 101, a transmission control unit 102, a transmission circuit 103, a transmission antenna 104, And a battery 105. The transmission circuit 103 includes a reference crystal resonator 106, a voltage controlled oscillator (VCO) 107, a PLL (Phase-Locked Loop) synthesizer 108, a loop filter 109, and an amplifier circuit 110. The PLL synthesizer 108 includes a phase comparator 111, a lock detection circuit 112, and frequency dividers 113 and 114.

  The transmission control unit 102 is configured using a so-called single-chip microcontroller having a ROM (Read Only Memory) in which a control program for controlling the operation of the transmission device 100 is stored, for example. To control the operation of the transmission apparatus 100. When the transmission control unit 102 receives the detection signal from the sensor 101, for example, the frequency division ratio R is supplied to the frequency divider 113 according to the setting content of the communication channel received by the operation switch (not shown) for setting the communication channel. The communication channel is set by setting the frequency division ratio N to the frequency divider 114.

  The PLL synthesizer 108 compares signals obtained by dividing the oscillation signal of the reference crystal oscillator 106 by R by the frequency divider 113 and dividing the oscillation signal of the voltage controlled oscillator 107 by N by the frequency divider 114 by the phase comparator 111. A phase difference signal representing the phase difference obtained in this way is output. The phase difference signal is smoothed by the loop filter 109 and then output to the voltage control terminal of the voltage controlled oscillator 107.

  The voltage controlled oscillator 107 oscillates at a frequency N / R times the oscillation signal output from the reference crystal resonator 106 after a predetermined time has elapsed. The lock detection circuit 112 detects that the phase difference represented by the phase difference signal output from the phase comparator 111 is equal to or less than a specified threshold value, and outputs a lock detection signal. When receiving the lock detection signal, the transmission control unit 102 transmits a specified communication format to the modulation input terminal of the voltage controlled oscillator 107 at a specified bit rate. Further, a prescribed communication format is modulated by the voltage controlled oscillator 107, amplified by the amplifier circuit 110, and radiated from the transmitting antenna 104.

  As the sensor 101, for example, various devices such as a push button switch, a reed switch, a power increase sensor, a temperature sensor, and a gas sensor are used.

  FIG. 10 is a diagram illustrating an example of a communication format used for the wireless communication as described above. A communication frame 201 shown in FIG. 10 includes a bit synchronization signal 202 (bit synchronization unit), a frame synchronization signal 203 (frame synchronization unit), an identification code 204 (identification code unit), command data 205, and a CRC (Cyclic Redundancy Check). ) Signal 206. The bit synchronization signal 202 is a repetitive pattern of “1” and “0” for achieving bit synchronization, and its signal waveform is a bit synchronization signal waveform 207. The frame synchronization signal 203 is a predetermined bit string for obtaining frame synchronization. For example, a bit string “100001110” is used as shown in the frame synchronization signal waveform 208. The identification code 204 is a unique bit string assigned without overlapping for each transmitting apparatus. Command data 205 is application control information. The CRC signal 206 is an error detection code between the identification code 204 and the command data 205 generated using a generator polynomial defined in advance.

  The bit rate and communication format are not standardized in the above-mentioned technical standards of the radio industry. However, since the allocation of the occupied frequency bandwidth is defined by the technical standards, the bit rate is determined within a certain range in order to communicate within the specified occupied bandwidth. Also, until the bit synchronization signal 202 is followed by the frame synchronization signal 203, it is a general format for wireless communication. Therefore, as long as the wireless device conforms to the technical standards of the radio industry, the bit synchronization signal 202 is often common even in different communication systems.

  FIG. 11 is a block diagram illustrating a configuration example of a low-power radio reception apparatus according to the background art. A reception device 120 illustrated in FIG. 11 is a wireless reception device that receives a wireless signal transmitted from the transmission device 100, for example, and includes a reception antenna 121, a reception circuit 122, a reception control unit 123, an LED (Light Emitting Diode) 124, and The application circuit 125 is configured. The reception circuit 122 includes a low noise amplifier 127, a SAW (Surface Acoustic Wave) filter 128, an RF mixer 129, a crystal filter 130, an IF mixer 131, a ceramic filter 132, a limiter amplifier 133, a demodulator 134, and an RSSI (Reception Strength Measurement Unit). It comprises a Received Signal Strength Indicator) circuit 135, a reference crystal resonator 136, a voltage controlled oscillator (VCO) 137, a PLL synthesizer 138, and a loop filter 139. The PLL synthesizer 138 includes a phase comparator 140 and frequency dividers 141 and 142.

  The reception control unit 123 is demodulated by a demodulator 134, for example, a ROM that stores a control program for controlling the operation of the reception device 120, an application program for executing processing according to the command data 205, and the like. A so-called single including a communication I / F unit 143 including, for example, a USART (Universal Synchronous and Asynchronous Receiver-Transmitter) that receives a serial signal, an AD converter 144 that digitally converts the voltage of an RSSI signal output from the RSSI circuit 135, and the like. A chip microcontroller is used to control the operation of the receiving device 120 by executing the control program.

  The operations of the reference crystal resonator 106, the voltage control oscillator 107, the PLL synthesizer 108, and the loop filter 109 in the transmission device 100 are performed by the reference crystal resonator 136, the voltage control oscillator 137, the PLL synthesizer 138, and the loop filter 139. Thus, the first local oscillation frequency signal having a frequency N / R times the oscillation signal output from the reference crystal resonator 136 is generated. The oscillation frequency of the reference crystal resonator 136 is used as the second local oscillation frequency.

  The radio signal received by the antenna 121 is amplified by the low noise amplifier 127 and filtered by the SAW filter 128. Since the center frequency of the SAW filter 128 matches the specified frequency to be received, interference signals and noise other than the frequency of the communication channel to be received are basically removed. Has a predetermined width, so that interference signals and noise near the radio signal pass through. Next, the radio signal is multiplied by the first local oscillation frequency by the RF mixer 129 and converted to a first intermediate frequency which is a difference between the radio signal and the first local oscillation frequency.

  The center frequency of the crystal filter 130 coincides with the first intermediate frequency. By filtering the first intermediate frequency signal with the crystal filter 130, the signal component of the radio signal and the first local oscillation frequency, and the prescribed signal to be received Interference signals and noise other than the frequency are basically removed, but since the pass band width of the crystal filter is wider than the bandwidth of the radio signal, the interference signal and noise near the radio signal pass through.

  Next, the first intermediate frequency signal is multiplied by the second local oscillation frequency by the IF mixer 131 and converted to a second intermediate frequency signal which is the difference between them. Since the center frequency of the ceramic filter 132 coincides with the second intermediate frequency and the pass bandwidth is equal to the bandwidth of the radio signal, the second intermediate frequency signal is filtered by the ceramic filter 132, so that The signal component of the first intermediate frequency and the second local oscillation frequency, the interference signal other than the prescribed frequency to be received, and noise etc. are basically removed from the two intermediate frequency signals. The interference signal and noise near the radio signal pass through.

  Next, the second intermediate frequency signal is amplified by the limiter amplifier 133 until the amplitude is saturated, the signal level such as the electric field strength in the received signal is measured by the RSSI circuit 135, and the voltage proportional to the received signal level is changed to the RSSI signal. Is input to the AD converter 144 of the reception control unit 123. The signal whose amplitude is saturated by the limiter amplifier 133 is demodulated by the demodulator 134 and output to the reception control unit 123 as a demodulated signal.

  The reception control unit 123 acquires the bit synchronization signal 202, the frame synchronization signal 203, the identification code 204, the command data 205, and the CRC signal 206 from the demodulated signal, and the reception control unit 123 according to the command data 205. An application program is to be executed.

  However, as described above, the radio signal received by the antenna 121 is filtered by the SAW filter 128, the crystal filter 130, and the ceramic filter 132, and basically includes interference signals other than the prescribed frequency to be received, noise, and the like. However, interference signals and noise near the radio signal pass through these filters and degrade the quality of the received signal. As a result, the target demodulated signal can be demodulated from the received signal. Even if it is not received or demodulated, a reception error such as the fact that the command data 205 or the like is mixed with noise and the contents of the data cannot be identified will occur.

Therefore, the reception control unit 123 acquires a signal level value indicating the signal level of the received signal by periodically analog-digital converting the RSSI signal output from the RSSI circuit 135 by the AD converter 144, and the signal level value However, the LED 124 is turned on when a predetermined criterion value is exceeded. By doing in this way, the user who uses the receiving device 120 can know the presence or absence of environmental noise and interference signals that exceed the determination reference value, and when the LED 124 is continuously lit, the environmental noise sources and interference signals It is possible to take measures such as increasing the distance from the source or changing the communication channels of the transmission device 100 and the reception device 120 (see, for example, Patent Document 1).
JP-A-5-175919

  By the way, when the LED is lit when the signal level of the received signal exceeds a preset determination reference value as in the above-described receiving device 120, a signal level equal to or higher than a certain value is used in the communication channel being used. The user can only know that there is some kind of device to be generated, and not only noise but also the LED lights even when the signal level of the received signal exceeds the judgment reference value, so that users who do not have expert knowledge can There is an inconvenience that it is difficult to find and treat the source and the interference signal source. In particular, in a security system such as home security in which a detection signal of a pyroelectric sensor for detecting a human body or a sensor for detecting that a window or the like has been opened is transmitted by power-saving radio, for example, 10 to 30 indoors. As a result of the installation of multiple transmitters, interference between each other's radio signals is likely to occur, and since many wireless devices have been commercialized for remote control applications in recent years, different products and products manufactured by different manufacturers When there is a reception abnormality due to radio wave interference between these products, it is very difficult to identify the cause of the reception abnormality only with information that the signal level of the received signal exceeds the criterion value. It was.

  The present invention has been made in view of such a problem, and an object of the present invention is to provide a receiving apparatus capable of reporting detailed information about the reception state of a communication signal.

  In order to achieve the above-described object, a receiving apparatus according to the present invention is a receiving apparatus that receives a communication signal of a communication frame having a bit synchronization unit at the head for bit synchronization, and receives the communication signal. A receiving unit, a bit synchronization detecting unit for detecting the bit synchronization unit from a communication signal received by the receiving unit, a reception intensity measuring unit for measuring a signal level of the communication signal, and a reception state of the communication signal. A notification level for reporting reception state information to be expressed, and a reference level in which the bit synchronization unit is not detected by the bit synchronization detection unit and the signal level of the communication signal measured by the reception intensity measurement unit is set in advance Exceeds the threshold, the determination unit determines that the abnormality is caused by the reception of noise by the reception unit, and the determination result by the determination unit is used as the reception status information as the report. It is characterized in that it comprises a control unit for informing the section.

  The above-described receiving device further includes a frame synchronization unit for synchronizing the communication frame with the communication frame, and detects the frame synchronization unit from the communication signal received by the reception unit. A frame synchronization detection unit, and the determination unit is different from the communication frame when the bit synchronization detection unit is further detected by the bit synchronization detection unit and the frame synchronization detection unit is not detected by the frame synchronization detection unit. It is characterized in that it is determined as an abnormality caused by reception of a communication signal of a communication frame.

  And the above-mentioned receiving apparatus is further provided with the identification code part showing the identification code for identifying the transmitting apparatus which transmits the said communication frame in the said communication frame, The transmitting apparatus which transmits the target communication frame which it is going to receive An identification code storage unit for storing the identification code, and an identification code detection unit for detecting the identification code unit from the communication signal received by the reception unit, wherein the determination unit is further configured by the bit synchronization detection unit. When the bit synchronization unit is detected and the identification code detected by the identification code detection unit does not represent any of the identification codes stored in the identification code storage unit, other than the target communication frame This is characterized in that it is determined as an abnormality caused by receiving the communication signal.

  Furthermore, the above-described receiving device further includes a pulse width measuring unit that measures a time width of a signal pulse in the communication signal received by the receiving unit, and the determination unit is configured so that the bit synchronization unit is detected by the bit synchronization detecting unit. When the time width detected and measured by the pulse width measurement unit is outside the range of the predetermined reference time width, it is determined that the abnormality is caused by the occurrence of the communication signal collision. It is characterized by being.

  Further, in the above-described receiving device, the determination unit is equal to or more than a preset number of the same logical value from the communication signal received by the receiving unit after the bit synchronization detecting unit is detected by the bit synchronization detecting unit. When a continuous signal is detected, it is determined that the abnormality is caused by the occurrence of a collision of the communication signals.

  In the above-described receiving device, the control unit may detect the bit synchronization unit by the bit synchronization detection unit and the signal level of the communication signal measured by the reception intensity measurement unit may be equal to or lower than the reference level. The notification unit is not notified of the reception state information.

  Then, the above-described receiving device stores a history storage unit that stores a history that is determined to be abnormal by the determination unit, and, when the determination unit determines that the abnormality is present, the type of abnormality and the occurrence time of the abnormality. Occurs within a predetermined period for each type of abnormality based on a history processing unit that cumulatively stores corresponding history information in the history storage unit and history information stored in the history storage unit And a statistical processing unit that generates abnormality occurrence frequency information representing the number of occurrences of abnormality by the type, and the control unit uses the abnormality occurrence frequency information generated by the statistical processing unit as the reception state information as the notification unit It is characterized by the fact that it is informed.

  Furthermore, in the above-described receiving device, when the occurrence number represented by the abnormality occurrence frequency information generated by the statistical processing unit is equal to or greater than a preset reference occurrence number, the control unit Is notified to the notification unit as the reception state information.

  In the above-described receiving device, the communication signal is transmitted through a plurality of communication channels, and the receiving unit is capable of switching a communication channel to be received in the plurality of communication channels, A channel information storage unit that stores communication channel identification information for identifying each of the plurality of communication channels; and the control unit further sequentially switches communication channels to be received by the reception unit, and the reception intensity measurement unit. The channel information storage unit stores communication channel identification information for identifying a communication channel in which the signal level of the measured communication signal is equal to or lower than the reference level. And storing the reception status information to the notification unit A communication channel identification information in Yan'neru information storage unit stored, and characterized in that to further notification to the notification section.

  In the receiving apparatus having such a configuration, when the bit synchronization detection unit does not detect the bit synchronization detection unit and the signal level of the communication signal measured by the reception intensity measurement unit exceeds the preset reference level, the reception unit Since it is possible to notify that an abnormality caused by the reception of noise has occurred, detailed information on the reception state of the communication signal can be notified.

  Embodiments according to the present invention will be described below with reference to the drawings. In addition, the structure which attached | subjected the same code | symbol in each figure shows that it is the same structure, The description is abbreviate | omitted.

(First embodiment)
FIG. 1 is a block diagram showing an example of a configuration of a receiving apparatus according to the first embodiment of the present invention. The receiving device 1 illustrated in FIG. 1 is a wireless receiving device that receives a wireless signal transmitted from the transmitting device 100, for example, and includes a reception control unit 2, a receiving antenna 121, and a receiving circuit 122. The reception control unit 2 is connected to LED3, LED4, LED5, LED6, LED7, liquid crystal display 8, external device I / F 9, telephone line I / F 10, application circuit 11, and push button switch 12. . LED3, LED4, LED5, LED6, LED7, and the liquid crystal display 8 are notification units that notify reception abnormality. Since the reception antenna 121 and the reception circuit 122 are the same as the reception antenna 121 and the reception circuit 122 illustrated in FIG. 11, the same components are denoted by the same reference numerals, and description thereof is omitted.

  The reception control unit 2 includes, for example, a CPU (Central Processing Unit), and for example, a control program for controlling the operation of the reception device 1 and an application program for executing processing according to the command data 205. Is output from the communication I / F unit 21 including the UART (Universal Asynchronous Receiver Transmitter), etc., and the RSSI circuit 135 for communicating with a ROM in which the information is stored, a personal computer connected to the external device I / F 9, etc. DTMF (Dual-Tone Multi Frequency) I which performs data transmission / reception by a multi-frequency code method (tone dialer) between the AD converter 22 for digitally converting the voltage of the RSSI signal and the public telephone network connected to the telephone line I / F 10 / F unit 23, identification of one or a plurality of transmission devices 100 to be a communication target in the reception device 1 An identification code storage unit 24 composed of, for example, a ROM for storing the code 204, and a pulse width measurement unit 25 configured to measure a signal pulse width in a demodulated signal from the demodulator 134, for example, using a timer. The CPU functions as a control unit, a bit synchronization detection unit, a frame synchronization detection unit, an identification code detection unit, and a determination unit by executing a control program stored in the ROM.

  The external device I / F 9 is, for example, a driver / receiver circuit compliant with the RS232 standard, and can be connected to a personal computer having a communication interface compliant with the RS232 standard. The external device I / F 9 converts the communication signal output from the communication I / F unit 21 into a signal level of the RS232 standard and transmits it to a personal computer (not shown) connected to the external device I / F 9. The RS232 standard signal transmitted from the personal computer is converted into a signal level that can be received by the communication I / F unit 21 and output to the communication I / F unit 21. Note that the external device I / F 9 is not limited to the RS232 standard, and may be another communication interface circuit such as USB (Universal Serial Bus) or Ethernet (registered trademark).

  The telephone line I / F 10 is a driver circuit that can be connected to a public telephone network and performs signal level conversion between the DTMFI / F unit 23 and the public telephone network. The application circuit 11 has an alarm buzzer when, for example, the sensor 101 in the transmission device 100 is a gas sensor and the reception device 1 is used as a gas leak alarm. For example, the sensor 101 in the transmission device 100 is a pyroelectric sensor (intrusion sensor). ) And when the receiving device 1 is used as a security device, it is a reporting device that reports to the security company via the public telephone network. For example, the sensor 101 in the transmission device 100 is a temperature sensor and the receiving device 1 is air-conditioned. When used as a temperature control device for an air conditioner, it is a temperature control circuit for an air conditioner or the like, and is a circuit provided according to the application.

  Next, the operation of the receiving apparatus 1 configured as described above will be described. FIG. 2 is a flowchart illustrating an example of the operation of the reception control unit 2. First, since the gain of the reception circuit 122 is very high, the thermal noise of the low noise amplifier 127 is amplified and input to the demodulator 134 even when the reception antenna 121 is not receiving a radio signal. 2, a noise-like demodulated signal obtained by demodulating thermal noise is always input.

  Therefore, the reception control unit 2 acquires a signal level value indicating the signal level of the received signal by performing analog-digital conversion on the RSSI signal output from the RSSI circuit 135 by the AD converter 144, and the signal level value is set in advance. If the determined reference value Vref (reference level) is exceeded (YES in step S1), the LED 3 indicating that the received signal level is high is turned on (step S2), and if not exceeded (NO in step S1). The process proceeds to step S3 without turning on the LED 3. For example, a value of about +1 to 6 dB with respect to the reception sensitivity (reception limit) of the reception circuit 122 is used as the determination reference value Vref. Thus, the user can know that there is some device that generates noise, a radio signal, or the like having a signal level of a certain value or higher in the communication channel being used.

  Next, the reception control unit 2 detects the edge of the pulse in the demodulated signal output from the demodulator 134, detects the time width of each pulse and the polarity of the pulse, and the demodulated signal is the signal of the bit synchronization signal 202. It is confirmed whether or not it matches the pattern (step S3). If it matches (YES in step S3), it is determined that bit synchronization has been established and the process proceeds to step S4 to check frame synchronization. In S3, the reception control unit 2 obtains a signal level value indicating the signal level of the received signal by performing analog-digital conversion on the RSSI signal output from the RSSI circuit 135 by the AD converter 144, and the signal level value is obtained in advance. If the set criterion value Vref is exceeded (YES in step S5), the environmental noise level is high. Turns on the LED4 which indicates the (step S6), and discards the received data that has already been acquired (step S7), and again proceeds to step S1.

  In this way, when the bit synchronization signal 202 cannot be detected and the signal level of the RSSI signal exceeds the determination reference value Vref, that is, a reception signal that does not include the bit synchronization signal 202 but exceeds the determination reference value Vref is received. In this case, since it is assumed that environmental noise is occurring and the LED 4 indicating that the level of the environmental noise is high is turned on, the user not only has an interference wave with a high signal level but also an environmental noise. For example, it is possible to determine that a reception abnormality has occurred. For example, it is possible to take measures such as separating an apparatus that is a source of environmental noise in the vicinity of the receiving apparatus 1 or changing a communication channel. Become.

  Next, in step S4, the reception control unit 2 confirms whether or not the frame synchronization signal 203 is detected within the preset number of bits after the bit synchronization signal 202 is detected (step S4). If the frame synchronization signal 203 is not detected (NO in step S4), the LED 5 indicating interference with another communication system is turned on (step S8), and the received data already acquired is discarded (step S7). If the frame synchronization signal 203 is detected (YES in step S4), the process proceeds to step S9 to detect the identification code 204.

  In this way, when the bit synchronization signal 202 is detected but the frame synchronization signal 203 cannot be detected, that is, when a reception signal including the bit synchronization signal 202 but having a different signal pattern is obtained. , It is estimated that interference has occurred with another communication system that uses a communication frame having a different signal pattern of the frame synchronization signal 203 for communication, and an abnormality caused by interference with the other communication system has occurred. Since the LED 5 indicating the occurrence is turned on, the user can know that the cause of the communication abnormality is in another communication system, for example, another communication system in the vicinity of the receiving device 1, for example, a different type It is possible to take measures such as separating communication systems used for products and products made by other manufacturers, changing communication channels, etc. It made.

  Next, in step S9, the reception control unit 2 confirms whether or not the identification code 204 included in the demodulated signal from the demodulator 134 matches the identification code 204 stored in the identification code storage unit 24. (Step S9) If the identification codes 204 do not match (NO in Step S9), the LED 6 indicating that the signal patterns of the bit synchronization signal 202 and the frame synchronization signal 203 interfere with the same type of communication system. Is turned on (step S10), the received data already acquired is discarded (step S7), and the process proceeds to step S1 again. On the other hand, if the identification codes 204 match (YES in step S9), the bit width is detected. Therefore, the process proceeds to step S11.

  In this way, when the bit synchronization signal 202 and the frame synchronization signal 203 are detected, but the identification code 204 does not match the identification code 204 stored in the identification code storage unit 24, that is, the bits included in the received signal. The signal pattern of the synchronization signal 202 and the frame synchronization signal 203 is the same type of communication system in which the signal pattern of the bit synchronization signal 202 and the frame synchronization signal 203 used by the reception device 1 is the same. 1 is estimated to have received a signal from the transmission device 100 that is not a communication target, and the LED 6 indicating that a communication signal of a communication system of the same type that is not a communication target has been received is lit. Therefore, the user determines that an abnormality has occurred due to interference with the same type of communication system. Becomes possible, for example, the receiving apparatus the same type of communication system in the vicinity of 1, and release the same manufacturer made of the communication system and for example the receiving apparatus 1, it becomes possible to perform treatment such changing the communication channel.

  Next, in step S13, the reception control unit 2 determines whether a communication signal collision has occurred. FIG. 3 is a diagram illustrating an example of a bit synchronization signal waveform 207a in the communication frame 201a when normally received and a bit synchronization signal waveform 207b in the communication frame 201b when a communication signal collision occurs. It is. For example, when the reception device 1 attempts to receive the communication frame 201a transmitted from the transmission device 100, if a wireless signal transmitted from a wireless transmission device such as another transmission device 100 collides with the communication frame 201a, two wireless frames are transmitted. As a result of the signal superposition, the signal waveform of the bit synchronization signal waveform 207a in which the 1-bit pulse width is set to the reference time width set in advance according to the bit rate is disturbed, and the received signal waveform after the collision is a communication frame. As in 201b, pulses different from the reference time width are mixed. Alternatively, for example, when the communication frame 201a is in a communication format in which the logical value “1” does not continue seven or more like the HDLC (High-Level Data Link Control) protocol, the received signal waveform after the collision is For example, a signal pattern in which seven or more logical values “1” are continuous is used.

  Therefore, in step S11, the pulse width measuring unit 25 measures the time width of the signal pulse in the demodulated signal from the demodulator 134. Then, the reception control unit 2 confirms whether or not the measurement value obtained by the pulse width measurement unit 25 is within a preset reference time width range, for example, a reference time width ± 5% range. If it is not within the set reference time width range (NO in step S11), the LED 7 indicating that a communication signal collision has occurred is turned on (step S12), and already received data is discarded (step S7). On the other hand, if the measured value is within the range of the preset reference time width (YES in step S11), the process proceeds to step S13 to confirm the number of consecutive logical values.

  In step S11, when a plurality of signal pulses having a time width outside the range of the reference time width are consecutive, for example, two in succession, the process proceeds to step S12 and a collision of communication signals occurs. It is good also as a structure by which LED7 which shows having lighted is lighted. As a result, it is reduced that a bit error that may occur in a normal state is determined to be due to a collision of communication signals.

  Next, in step S13, the reception control unit 2 counts the number of consecutive logical values in the demodulated signal from the demodulator 134. For example, when the communication frame 201a is a communication format in which the logical value “1” is a predetermined reference number, for example, 7 or more, the number of consecutive logical values “1” by the reception control unit 2 If the count result is 7 or more (NO in step S13), the communication frame 201a is not normal, so the LED 7 indicating that a communication signal collision has occurred is turned on (step S12), and the reception that has already been acquired. The data is discarded (step S7), and the process proceeds to step S1 again. On the other hand, if the count result is less than 7 (YES in step S13), the process proceeds to step S14 to check the CRC signal 206.

  In this way, when the bit synchronization signal 202 and the frame synchronization signal 203 are detected and the identification code 204 matches the identification code 204 stored in the identification code storage unit 24, the demodulation from the demodulator 134 is performed. When the time width of the signal pulse in the signal is outside the range of the preset reference time width, or when the same logical value is continuously detected for a predetermined reference number or more in the demodulated signal from the demodulator 134 In addition, since it is estimated that an abnormality caused by a collision between a target communication signal and a non-target communication signal has occurred, the LED 7 indicating that a communication signal collision has occurred is lit. The user can determine that an abnormality has occurred due to a communication signal collision.

  For example, when a transmitter that detects a human body using a pyroelectric sensor and transmits a visitor or an intrusion is installed in the vicinity, such a radio signal collision may occur frequently. . If the LED 7 is lit in such a case, the user can determine that the distance between the plurality of transmitters needs to be set farther apart in practice.

  Further, the LEDs 3 to 7 which are turned on by the reception control unit 2 in steps S6, S8, S10 and S12 are turned off when the reception control unit 2 detects that the push button switch 12 is pressed by the user. Has been. As a result, for example, reception abnormalities caused by environmental noises generated when the user is not looking at the LEDs 3 to 7 such as environmental noises and interference signals that occur intermittently, environmental noises and interference signals that occur only at midnight, and the like. In addition, the cause of the reception abnormality can be determined by the user confirming the lighting state of the LEDs 3 to 7 after the reception abnormality occurs.

  Further, the user can know that there is some device that generates a signal level higher than a certain value in the communication channel being used if the LED 3 is lit, and if the LED 4 is lit, environmental noise is generated. If the LED 5 is lit, it is possible to know that interference with another communication system has occurred. If the LED 6 is lit, the communication system is the same type and the receiving device 1, it is possible to know that a signal from the transmission device 100 that is not a communication target has been received. If the LED 7 is lit, it can be known that a communication signal collision has occurred. The reception state information, which is detailed information about the reception state of the communication signal, can be notified.

  Next, in step S14, the reception control unit 2 compares the CRC code generated from the identification code 204 and the command data 205 received from the demodulator 134 with the CRC signal 206 received from the demodulator 134 ( If the comparison result does not match (NO in step S14), it is determined that the received data is not normal, the received data already acquired is discarded (step S7), and the process proceeds to step S1 again. If the comparison results match (YES in step S14), it is determined that the received data is normal, and the operation of the application circuit 11 is controlled according to the received command data 205 (step S15).

  Note that when the signal level of a target reception signal received by the reception antenna 121 is a low level close to reception sensitivity, a random error may occur due to the influence of thermal noise generated in the reception circuit 122. . Thus, when a random error due to thermal noise occurs, the frame synchronization signal 203 is not detected in steps S4, S9, S11, and S13 (NO in step S4), and the identification codes 204 do not match (NO in step S9). The time width measurement value of the signal pulse is less than the preset reference time width (NO in step S11), and the counting result of the continuous number of logical values “1” is determined to be greater than or equal to the reference number (NO in step S13). As a result, the LEDs 5, 6, and 7 are turned on in steps S8, S10, and S12 in spite of the reception abnormality caused by the thermal noise. "Interference with", "Receiving signal from transmission device 100 that is not communication target", "Communication signal collision", etc. Mau and thus.

  Therefore, for example, as shown in FIG. 4, after bit synchronization is confirmed in step S <b> 3, in step S <b> 3 a, the reception control unit 2 performs analog-digital conversion on the RSSI signal output from the RSSI circuit 135 by the AD converter 22. The signal level value indicating the signal level of the received signal is acquired by the above, and only when the signal level value exceeds the determination reference value Vref, the process proceeds to step S4 to continue the reception process after step S4 (YES in step S3a). On the other hand, if the signal level value is less than or equal to the determination reference value Vref, the received data already acquired by determining that it is difficult to continue normal reception due to the influence of thermal noise and to correctly notify the cause of reception abnormality. May be discarded (step S7) and the process may proceed to step S1 again.

  In this case, the reception control unit 2 turns on the LEDs 4, 5, 6, and 7 regardless of the determination results in steps S4, S9, S11, and S13 when the signal level of the reception signal that is the reception target is low. Since reception status information is not notified, it is possible to reduce notification of erroneous reception status information regarding the reception status of the communication signal to the user due to the influence of thermal noise.

  In addition, although the example which alert | reports to a user the reception status information which is detailed information about the reception status of a communication signal using LED3-7 was shown, the reception control part 2 is "environment". The reception state information may be displayed by a message such as “noise is generated” or “interference with another communication system”, and the personal computer (not shown) connected to the external device I / F 9 by the communication I / F unit 21. A configuration may be adopted in which the reception status information is transmitted to the computer, and the DTMFI / F unit 23 is configured to transmit the reception status information to a predetermined notification destination such as a management center via the telephone line I / F 10 and the public telephone network. It is good.

  Further, although the receiving device 1 has been described by taking a wireless receiving device that receives a wireless signal as an example, the receiving device 1 may be a receiving device used for wired communication.

(Second Embodiment)
Next, a receiving apparatus according to the second embodiment of the present invention will be described. FIG. 5 is a block diagram illustrating an example of a configuration of a receiving apparatus according to the second embodiment. The receiving device 1a shown in FIG. 5 is different from the receiving device 1 shown in FIG. 1 in the following points. That is, in the receiving apparatus 1a shown in FIG. 5, the reception control unit 2a further includes a history storage unit 26 made of, for example, EEPROM (Electrically Erasable and Programmable Read Only Memory), and a clock unit 27 made of, for example, a real-time clock. It also functions as a processing unit and a statistical processing unit. Since the other configuration is the same as that of the receiving apparatus 1 shown in FIG. 1, the description thereof is omitted, and the operation of the reception control unit 2a in the present embodiment will be described below.

  FIG. 6 is a flowchart illustrating an example of the operation of the reception device 1a illustrated in FIG. In addition, the same code | symbol is attached | subjected to the operation | movement similar to the flowchart shown in FIG. 2, and the description is abbreviate | omitted. In the flowchart shown in FIG. 6, after the LED lighting process in steps S6, S8, S10, and S12, the process proceeds to step S16.

  In step S16, the reception control unit 2a causes the history storage unit 26 to receive reception state information, for example, reception state information indicating occurrence of an abnormality such as “occurrence of environmental noise” and “interference with another communication system”. The information is accumulated and stored in the history storage unit 26 in association with the time information representing the current time obtained by 27 (step S16). Based on the number of reception status information stored for each type of reception status information stored in the history storage unit 26 and the time information stored corresponding to the reception status information by the reception control unit 2a, Anomaly occurrence frequency information that is the number of occurrences of each type of anomaly within a predetermined period is generated (step S17).

  Next, the reception control unit 2a compares the notification time, which is a preset time for reporting the abnormality occurrence frequency information, with the current time obtained by the clock unit 27 (step S18), and the current time is If it coincides with the notification time (YES in step S18), the type of abnormality indicated by the reception state information stored in the history storage unit 26, the abnormality occurrence time, and abnormality occurrence frequency information about the abnormality are statistical. Information is updated and displayed on the liquid crystal display 8 (step S19), and the received data already acquired is discarded (step S7). Then, the process proceeds to step S1 again, and the processes of steps S1 to S19 are repeated.

  As described above, by the processing of steps S1 to S19, “occurrence of environmental noise”, “interference with other communication systems”, “reception of a signal from the transmission apparatus 100 that is not a communication target” in the reception state of the communication signal for the user, and Since the reception status information indicating the cause of reception abnormality such as “communication signal collision” and statistical information indicating the occurrence time and frequency of the abnormality are updated and displayed on the liquid crystal display 8 once every 24 hours, for example. The occurrence frequency and occurrence time can be notified to the user according to the cause of the occurrence of reception abnormality. As a result, the user is freed from the hassle of manually analyzing the occurrence history of reception abnormalities, and the necessity of countermeasures for reception abnormalities is determined from the frequency and time of occurrence of reception abnormalities, and the interference wave source is specified. It becomes easy to do. Further, for example, since the occurrence of an abnormality such as a reception abnormality frequently occurring at a predetermined time is known, the interference wave source is identified by conducting an investigation of the site where the receiving device 1 is installed at such an abnormality occurrence time. Easy to do.

  In addition, since the reception status information and statistical information within a certain period are notified by the liquid crystal display 8, for example, environmental noise and interference signals that occur intermittently, environmental noise and interference signals that occur only at midnight, etc. The user can also grasp the reception abnormality caused by the environmental noise or the like generated when the user is not looking at the LEDs 3 to 7 from the reception state information and the statistical information notified by the liquid crystal display 8.

  Note that the reception status information and statistical information are not limited to the example that is periodically updated and displayed on the liquid crystal display 8. For example, when the reception control unit 2a detects that the push button switch 12 is pressed, the liquid crystal display is performed. The structure displayed on the container 8 may be sufficient.

  Further, for example, the LED is not turned on in steps S6, S8, S10, and S12, and in step S17, the reception control unit 2a compares the abnormality occurrence frequency information with a predetermined abnormality occurrence reference number, and the abnormality occurrence frequency. When the information exceeds the abnormality occurrence reference count, an LED corresponding to the abnormality may be turned on, and reception status information and statistical information corresponding to the abnormality may be displayed on the liquid crystal display 8. Thereby, only when the occurrence frequency of the abnormality during the predetermined period exceeds the abnormality occurrence reference number, the reception state that is the detailed information about the reception state of the communication signal using the LED 5, LED 6, LED 7, and the liquid crystal display 8 or the like. Since information and statistical information can be notified to the user, information that does not occur frequently and therefore does not cause a problem in practical operation is discarded, and only frequently useful reception status information and statistical information are notified to the user. be able to.

  The reception control unit 2a receives a request command for requesting reception state information and statistical information from a personal computer (not shown) connected to an external device I / F 9 such as an RS232 interface by the communication I / F unit 21. In this case, the communication I / F unit 21 may be configured to transmit reception state information and statistical information to the personal computer via the external device I / F 9. In this way, by configuring the external device I / F 9 so that reception status information and statistical information can be transmitted to an external device such as a personal computer, a user or maintenance personnel can receive from the receiving device 1 using the external device. The status information and the statistical information can be read, and for example, the user or maintenance personnel can take the external device back to another place and analyze the reception abnormality.

  In addition, the reception control unit 2a causes the DTMFI / F unit 23 to communicate with the management center that is a predetermined notification destination via the public telephone network from the telephone line I / F 10, and in response to a request command from the management center, statistics are received. Information may be transmitted. As described above, the reception state, which is detailed information about the reception state of the communication signal in the reception device 1, by transmitting the reception state information and the statistical information to the remote management center or personal computer via the public telephone network. Information and statistical information can be notified to remote managers, maintenance contractors, etc., for example, the manager or the like can use the LEDs 3 to 7 or the liquid crystal display 8 or the like for the first time at the site where the receiving device 1 is installed. Compared with the case where the reception state information and statistical information are grasped, it is possible to take measures against reception abnormality at an early stage.

(Third embodiment)
Next, a receiving apparatus according to the third embodiment of the present invention will be described. FIG. 7 is a block diagram illustrating an example of a configuration of the receiving device 1b according to the third embodiment. The receiving apparatus 1b shown in FIG. 7 differs from the receiving apparatus 1a shown in FIG. 5 in the following points. That is, the receiving apparatus 1b illustrated in FIG. 7 further includes a channel information storage unit 28 including, for example, a RAM (Random Access Memory) that stores search results of usable communication channels in the reception control unit 2b, and the reception control unit 2b. The operation of is different. Since the other configuration is the same as that of the receiving apparatus 1 shown in FIG. 5, the description thereof is omitted, and the operation of the reception control unit 2 b in the present embodiment will be described below.

  FIG. 8 is a flowchart showing an example of the operation of the reception control unit 2b shown in FIG. The reception control unit 2b operates according to the flowchart shown in FIG. 6, similarly to the reception control unit 2a shown in FIG. Furthermore, in the process of repeating the processes of steps S1, S2, S3, S5, and S7 without receiving the bit synchronization, that is, the process of repeating steps S1, S2, S3, S5, and S7, for example, in advance The free communication channel search process shown in FIG. 8 is executed at set time intervals.

  First, the reception control unit 2b changes a communication channel to be received so as to search for an unused communication channel that is not used (step S101). Specifically, the frequency division ratio R of the frequency divider 141 and the frequency division ratio N of the frequency divider 142 are changed by the reception control unit 2b, and the reference crystal resonator 136, the voltage controlled oscillator 137, the PLL synthesizer 138, The communication channel to be received is changed by changing the frequency of the first local oscillation frequency signal generated by the loop filter 139.

  Next, the reception control unit 2b obtains a signal level value indicating the signal level of the received signal by analog-digital conversion of the RSSI signal output from the RSSI circuit 135 by the AD converter 22, and the signal level value is a communication signal. And a level indicating the presence of environmental noise, for example, a determination reference value Vref (step S102). If the signal level value exceeds the determination reference value Vref as a result of comparison by the reception control unit 2b (YES in step S102), the changed communication channel is stored in the channel information storage unit 28 as “signal present”. On the other hand, if the signal level value is equal to or less than the determination reference value Vref (NO in step S102), the changed communication channel is stored in the channel information storage unit 28 as “no signal” (step S104).

  Next, the frequency division ratio R of the frequency divider 141 and the frequency division ratio N of the frequency divider 142 are changed by the reception control unit 2b to change again to the communication channel intended for reception, and the first local oscillation frequency signal Are changed to the communication channel to be received (step S105), and the processes of steps S1 to S19 shown in FIG. 6 are executed again.

  As described above, the processing in steps S101 to S105 is repeated by the reception control unit 2b at, for example, predetermined time intervals, so that communication that is not used by other communication devices and does not have environmental noise. The channel is stored in the channel information storage unit 28 as “no signal”.

  The reception control unit 2b displays the communication channel stored as “no signal” in the channel information storage unit 28 together with the statistical information in step S19 as a communication channel change destination candidate. The reception control unit 2b performs communication when the communication I / F unit 21 receives a request command for requesting statistical information from an unillustrated personal computer connected to an external device I / F 9 such as an RS232 interface. The I / F unit 21 may be configured to transmit statistical information to the personal computer via the external device I / F 9 and to transmit information indicating a communication channel as a communication channel change destination candidate. Further, the reception control unit 2b causes the DTMFI / F unit 23 to communicate with the management center that is a predetermined notification destination from the telephone line I / F 10 via the public telephone network, and in response to a request command from the management center, It is good also as a structure which transmits the information which shows the communication channel used as a communication channel change destination candidate while transmitting information.

  In this way, the reception control unit 2b searches for a free communication channel, and the user is notified of the searched free communication channel when a reception abnormality occurs. Therefore, the user, maintenance personnel, or a remote management center In this case, the user or maintenance personnel can know from the reception control unit 2b when a reception abnormality occurs due to environmental noise or the like in the communication channel currently in use. It is possible to avoid a reception abnormality by changing to a communication channel notified as a communication channel change destination candidate.

It is a block diagram which shows an example of a structure of the receiver which concerns on the 1st Embodiment of this invention. 3 is a flowchart illustrating an example of an operation of a reception control unit illustrated in FIG. It is a figure which shows an example of the signal waveform for bit synchronization in the communication frame at the time of receiving normally, and the signal waveform for bit synchronization in the communication frame when the collision of the communication signal has generate | occur | produced. 6 is a flowchart illustrating another example of the operation of the reception control unit illustrated in FIG. 1. It is a block diagram which shows an example of a structure of the receiver which concerns on 2nd Embodiment. It is a flowchart which shows an example of operation | movement of the reception control part shown in FIG. It is a block diagram which shows an example of a structure of the receiver which concerns on 3rd Embodiment. It is a flowchart which shows an example of operation | movement of the reception control part shown in FIG. It is a block diagram which shows the structure of the transmitter in the low power radio | wireless machine which concerns on background art. It is a figure which shows an example of a communication format. It is a block diagram which shows the structural example of the receiving apparatus of the low power radio | wireless which concerns on background art.

Explanation of symbols

1, 1a, 1b Receiver 2, 2a, 2b Reception control unit 3, 4, 5, 6, 7 LED
8 Liquid crystal display 9 External device I / F
10 Telephone line I / F
11 Application Circuit 12 Push Button Switch 21 Communication I / F Unit 22 AD Converter 23 DTMFI / F Unit 24 Identification Code Storage Unit 25 Pulse Width Measurement Unit 26 History Storage Unit 27 Clock Unit 28 Channel Information Storage Unit 120 Receiving Device 121 Receiving Antenna 122 Reception circuit 135 RSSI circuit 136 Reference crystal resonator 201, 201a, 201b Communication frame 202 Bit synchronization signal 203 Frame synchronization signal 204 Identification code

Claims (9)

A receiving device that receives a communication signal of a communication frame having a bit synchronization unit at the head for bit synchronization,
A receiving unit for receiving the communication signal;
A bit synchronization detection unit for detecting the bit synchronization unit from a communication signal received by the reception unit;
A received intensity measuring unit for measuring a signal level of the communication signal;
A notification unit for reporting reception state information indicating a reception state of the communication signal;
When the bit synchronization unit is not detected by the bit synchronization detection unit and the signal level of the communication signal measured by the reception intensity measurement unit exceeds a preset reference level, noise is received by the reception unit. A determination unit that determines that the abnormality is caused by
And a control unit that causes the notification unit to notify the determination result by the determination unit as the reception state information. The communication frame further includes a frame synchronization unit for synchronizing the frame with the communication frame,
A frame synchronization detection unit for detecting the frame synchronization unit from the communication signal received by the reception unit;
The determination unit further receives a communication signal of a communication frame different from the communication frame when the bit synchronization detection unit detects the bit synchronization unit and the frame synchronization detection unit does not detect the frame synchronization unit. The receiving apparatus according to claim 1, wherein the receiving apparatus determines that an abnormality is caused by the problem. The communication frame further includes an identification code unit representing an identification code for identifying a transmission device that transmits the communication frame,
An identification code storage unit that stores an identification code of a transmission device that transmits a target communication frame to be received;
An identification code detection unit that detects the identification code unit from the communication signal received by the reception unit;
The determination unit further detects which of the identification codes stored in the identification code storage unit is the identification code detected by the bit synchronization detection unit and the identification code detected by the identification code detection unit. 3. The receiving apparatus according to claim 1, wherein the receiving apparatus determines that the abnormality is caused by receiving a communication signal other than the target communication frame. A pulse width measuring unit for measuring a time width of a signal pulse in the communication signal received by the receiving unit;
The determination unit is configured to detect the communication signal when the bit synchronization unit is detected by the bit synchronization detection unit and the time width measured by the pulse width measurement unit is outside a predetermined reference time range. The receiving apparatus according to claim 1, wherein the receiving apparatus determines that the abnormality is caused by the occurrence of a collision.   When the determination unit detects a signal in which the same logical value continues for a preset number or more from the communication signal received by the reception unit after the bit synchronization detection unit detects the bit synchronization unit. The receiving apparatus according to claim 1, wherein the receiving apparatus determines that the abnormality is caused by the occurrence of a collision of the communication signals.   When the bit synchronization unit is detected by the bit synchronization detection unit and the signal level of the communication signal measured by the reception intensity measurement unit is equal to or lower than the reference level, the control unit notifies the notification unit of the reception state. The receiving apparatus according to claim 1, wherein the information is not notified. A history storage unit for storing a history determined to be abnormal by the determination unit;
A history processing unit that cumulatively stores in the history storage unit history information that associates the type of abnormality and the time of occurrence of the abnormality when the determination unit determines that the abnormality has occurred;
Based on the history information stored in the history storage unit, for each type of abnormality, a statistical processing unit that generates abnormality occurrence frequency information indicating the number of occurrences of abnormality due to the type occurring within a predetermined period of time, and With
The receiving device according to claim 1, wherein the control unit causes the notification unit to notify the abnormality occurrence frequency information generated by the statistical processing unit as the reception state information. .   When the occurrence number represented by the abnormality occurrence frequency information generated by the statistical processing unit is equal to or greater than a preset reference occurrence number, the control unit notifies the abnormality occurrence frequency information as the reception state information. The receiving apparatus according to claim 7, wherein the receiving apparatus is notified. The communication signal is transmitted by a plurality of communication channels,
The receiving unit is capable of switching a communication channel to be received in the plurality of communication channels,
A channel information storage unit for storing communication channel identification information for identifying each of the plurality of communication channels;
The control unit further sequentially switches communication channels to be received by the receiving unit, and causes the reception intensity measurement unit to measure the signal level of the communication signal in each of the sequentially switched communication channels. Communication channel identification information for identifying a communication channel whose signal level is equal to or less than the reference level is stored in the channel information storage unit, and when the reception state information is notified to the notification unit, the channel information storage unit The receiving apparatus according to claim 1, wherein the notification unit further notifies the stored communication channel identification information to the notification unit.

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