JP2010010871A - Wireless transmission device, and wireless communication system using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wireless transmission device capable of easily reducing the passband width of an IF filter of a wireless reception device while reducing possibility of increase of a communication time; and a wireless communication system. <P>SOLUTION: This wireless transmission device carrying out modulation by deviating the frequency of a wireless signal from a carrier frequency includes: a bit synchronization signal transmission part 21 transmitting at least a part of a bit synchronization code string having preset regularity by using a wireless signal in which a frequency deviation amount from the carrier frequency is a first deviation amount f<SB>DEV1</SB>; and a data transmission part 23 transmitting a data code string representing data by using a wireless signal in which a frequency deviation amount from the carrier frequency is a set deviation amount f<SB>DEVS</SB>set at a value larger than that of the first deviation amount f<SB>DEV1</SB>after the bit synchronization signal is transmitted. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a radio transmission apparatus using FSK (Frequency Shift Keying) or FM (Frequency Modulation) modulation, and a radio communication system using the same.

  In a wireless communication system that transmits a large amount of data such as high-definition images and moving images, it is needless to say that a high communication speed is required, but a wireless communication system that transmits a relatively small amount of data such as a control signal of a device. In some cases, a high communication speed may be required. One example is a case where the transmitter is driven by a battery as a power source.

  In battery-powered transmitters, it is particularly strongly required to reduce power consumption. By reducing power consumption, small batteries can be used and the equipment can be miniaturized. There is no need for battery replacement or charging (or frequency can be reduced), so maintenance is improved and battery replacement is possible. In addition, it is not necessary to adopt a structure that can be charged and various advantages can be obtained, such as downsizing and cost reduction of the device.

  One method for reducing the power consumption of the transmitter is to shorten the communication time. When transmitting a certain amount of data, the time for driving the transmitter can be shortened as the communication time is shortened. As a result, power consumption can be reduced.

  FIG. 16 is a block diagram illustrating a configuration of a wireless communication system according to the background art. The wireless communication system illustrated in FIG. 16 includes a wireless transmission device 100 and a wireless reception device 110. The wireless transmission device 100 includes a transmission control circuit 101, a transmission RF (Radio Frequency) circuit 102, a power amplifier 103, a transmission antenna 104, and a reference oscillator 105. When the transmission control circuit 101 detects a transmission trigger, it transmits transmission data to the transmission RF circuit 102.

  The transmission RF circuit 102 performs a predetermined FM modulation operation on transmission data using the oscillation signal having the reference oscillation frequency generated by the reference oscillator 105, and sends the modulation signal to the power amplifier 103. The reference oscillation frequency is used as a carrier wave frequency, for example.

  The power amplifier 103 amplifies the modulated signal, transmits it to the transmitting antenna 104, and radiates it from the transmitting antenna 104 to space. The transmission RF circuit is configured so that the frequency deviation is variable when performing the FM modulation operation, and the frequency deviation is controlled by the transmission control circuit 101.

  The radio reception apparatus 110 includes a reception antenna 111, a low noise amplifier 112, an RF filter 113, a mixer 114, an IF (Intermediate Frequency) filter 115, an IF amplifier 116, a detector 117, a baseband circuit unit 118, an automatic frequency adjustment circuit 119, and The local oscillation circuit 120 is configured.

  The high frequency signal received by the receiving antenna 111 is amplified by the low noise amplifier 112 and unnecessary frequency components are removed by the RF filter 113, and then the reference oscillation frequency (local oscillation frequency) output from the local oscillation circuit 120 by the mixer 114. It is mixed with the output signal and converted to an IF signal. The IF signal is subjected to removal of unnecessary frequency components by the IF filter 115, amplified by an IF amplifier, frequency-voltage converted by a detector 117, and then transmitted to a baseband circuit unit 118.

  Here, when the reference oscillation frequency of the wireless transmission device 100 and the reference oscillation frequency of the wireless reception device 110 are shifted from each other due to the influence of temperature, the IF frequency of the IF signal deviates from the design value. At this time, the signal subjected to frequency-voltage conversion by the detector 117 is also deviated from the design value, and the reception sensitivity is lowered.

  Therefore, the output signal of the detector 117 is input to the automatic frequency adjustment circuit 119. Then, the automatic frequency adjustment circuit 119 adjusts the local oscillation frequency of the local oscillation circuit 120 to match the reference oscillation frequency of the wireless transmission device 100 so that the IF frequency converges to the design value, thereby reducing the reception sensitivity. (For example, refer patent document 1).

In general, in a radio communication system using an FSK modulation scheme or an FM modulation scheme, it is necessary to increase the frequency deviation in order to achieve both high communication speed and high communication reliability. When the frequency deviation is increased, the frequency spectrum of the modulation signal is expanded, and accordingly, the pass band width of the IF filter 115 provided in the wireless reception device 110 needs to be designed to be wide. When the modulation frequency is f _MOD and the frequency shift is f _DEV , the pass bandwidth B _IF ′ required for the IF filter 115 is approximately expressed by the following equation (2) (Carson rule).

B _IF '≧ 2 × (f _MOD + f _DEV ) (2)
Further, in order to reduce the cost of the wireless communication system, a low-cost oscillator having no temperature compensation function is used for the reference oscillator 105 on the wireless transmission device 100 side or the local oscillation circuit 120 of the wireless reception device 110. There is. In such a case, since it is necessary to consider the temperature change of the reference oscillation frequency of each transceiver, the pass bandwidth B _IF required for the IF filter 115 is expressed by the following equation (3).

B _IF ≧ 2 × (f _MOD + f _DEV + Δf _TX + Δf _RX ) (3)
Here, Δf _TX is the maximum deviation of the reference oscillation frequency on the transmitter side (maximum value of deviation), and Δf _RX is the maximum deviation of the reference oscillation frequency on the receiver side (maximum deviation absolute value). Value).

  On the other hand, the reception sensitivity SS of the wireless receiver 110 receiver is generally expressed by the following equation (4).

SS [dBm] = − 174 [dBm] +10 log F + 10 log B _IF + 10 log (S / N) (4)
Here, -174 [dBm] is the passband bandwidth B _IF = 1 [Hz] in the 50Ω system, the thermal noise power under the condition of room temperature 290 [K], F is the noise figure of the receiver, and 10 log B _IF is the pass bandwidth. The amount of change in noise power due to B _IF , 10 log (S / N) is the SN ratio (signal-to-noise ratio) required for the receiver.

The reception sensitivity SS is the minimum reception power required for the radio reception apparatus 110 to normally demodulate the radio signal. Therefore, the smaller the reception sensitivity SS is, the better the sensitivity of the radio reception apparatus 110 is. Then, from equation (4), it is clear that the influence of noise power is reduced and the reception sensitivity of the wireless reception device 110 is improved as the pass bandwidth B _IF of the IF filter 115 is narrower (the value is smaller).

However, since the pass bandwidth B _IF of the IF filter 115 needs to satisfy the expression (3) in order to pass the modulation signal with certainty, the communication speed is high (therefore, the value of the modulation frequency f _MOD is large). Indeed, the pass bandwidth B _IF of the IF filter 115 must be increased (larger).

  Here, the automatic frequency adjustment circuit 119 corrects the deviation of the reference oscillation frequency between the transmitter and the receiver from the output signal of the detector 117 (= the reference oscillation frequency of the transmitter and the reference of the receiver). The oscillation frequency shift) is detected, and the reference oscillation frequency of the local oscillation circuit 120 is adjusted based on the detection result to correct the IF frequency shift.

  After the automatic frequency adjustment by the automatic frequency adjustment circuit 119 is completed, the IF frequency shift becomes almost zero, so that the detector 117 can be operated at the highest sensitivity frequency. In order to perform a normal demodulation operation, the automatic frequency adjustment circuit 119 is sufficiently large with respect to the product of the maximum number that the same code may continue and the bit length in the communication protocol in the communication system. Must have a constant.

  Therefore, it takes time corresponding to the time constant from the start of reception until the frequency adjustment is completed. In addition, the deviation of the reference oscillation frequency between the transmitter and the receiver cannot be ignored during the period from the start of reception to the completion of frequency adjustment.

  FIG. 17 is an explanatory diagram showing an example of the operation of the wireless communication system shown in FIG. As shown in FIG. 17A, the wireless signal transmitted from the wireless transmission device 100 is roughly divided into three parts: a bit synchronization signal, a frame synchronization signal, and data. The bit synchronization signal is a signal for achieving bit synchronization with the receiver, and is a repetitive signal of 1010. The frame synchronization signal is a signal for achieving frame synchronization with the receiver, and a specific pattern is set according to the communication system. Data is a bit string including information that is actually desired to be communicated, and varies depending on the content of communication, and generally has a random pattern.

As shown in FIG. 17B, the IF frequency design value is f _IF0 , the elapsed time from the start of automatic frequency adjustment by the automatic frequency adjustment circuit 119 is t, and the deviation from the IF frequency design value at time t. If the maximum absolute value of Δf _IF (t) is Δf _IF (t), the maximum absolute value Δf _IF (0) of the deviation from the design value f _IF0 when automatic frequency adjustment is started (t = 0) is , Δf _TX + Δf _RX .

As the automatic frequency adjustment circuit 119 executes automatic frequency adjustment (with the elapse of time t), the frequency of the oscillation signal output from the local oscillation circuit 120 is adjusted, and Δf _IF (t) is substantially “0”. Converge to.

As described above, after the automatic frequency adjustment is completed, the deviation of the IF frequency becomes almost “0”, but immediately after the start of communication, Δf _{IF (0)} = Δf _TX + Δf _RX is the maximum on the transmission side. There is a possibility that the IF frequency shifts with the receiving side. For this reason, even if the automatic frequency adjustment circuit 119 is provided, the pass bandwidth B _IF of the IF filter 115 needs to satisfy Expression (3). Accordingly, as shown in FIG. 17C, at time t = 0, at least B _IF = 2 × (f _MOD + f _DEV + Δf _TX + Δf _RX ).

That is, when the temperature change of the reference oscillation frequency is large, the pass bandwidth B _IF of the IF filter 115 needs to be increased (increased) accordingly. As a result, the reception sensitivity SS is deteriorated (increased) according to the equation (4).

Thus, there is a communication system that allows the wireless transmission device 100 to continue transmitting dummy signals until the automatic frequency adjustment is completed, thereby reducing the pass bandwidth B _IF of the IF filter 115 on the wireless reception device 110 side. Are known.

FIG. 18 is an explanatory diagram for explaining the operation of such a wireless communication system. The wireless transmission device 100 first transmits a non-modulated (carrier frequency) dummy signal, and transmits a signal to be originally transmitted after the automatic frequency adjustment in the wireless reception device 110 is completed. Thereby, when the radio receiving apparatus 110 starts reception, the radio signal (dummy signal) does not include the modulation frequency f _MOD and the frequency shift f _DEV , so that the pass required for the IF filter 115 is performed. The bandwidth B _IF is 2 × (Δf _TX + Δf _RX ) as shown in FIG. 18 (c), which is smaller than the pass bandwidth B _IF shown in FIG. 17 (c). It is possible to use the IF filter 115 having a smaller pass bandwidth B _IF than when not used.
Japanese Patent Laid-Open No. 58-14618

  However, as described above, when a dummy signal is added, there is a problem that the total communication time is increased correspondingly, and the power consumption of the wireless transmission device 100 is increased. As described above, particularly in a battery-driven transmission device, reduction in power consumption is strongly demanded, and the demerit of increase in power consumption is great.

  An object of the present invention is to provide a wireless transmission device and a wireless communication system that can easily reduce the passband width of an IF filter in a wireless reception device while reducing the possibility of an increase in communication time.

  A radio transmission apparatus according to the present invention is a radio transmission apparatus that modulates a frequency of a radio signal by shifting from a carrier frequency, and a frequency shift amount from the carrier frequency is a predetermined first shift amount. A first transmission unit that executes a first shift signal transmission process for transmitting at least a part of a first set code sequence having a predetermined regularity using a certain radio signal, and the first transmission unit After the first set code string is transmitted, a data code representing data using a radio signal whose set deviation amount is set to a value larger than the first deviation amount. A data transmission unit that executes a data transmission process of transmitting a column;

  According to this configuration, before transmission of the data code sequence by the data transmission unit, first, the first setting code sequence is regularized by the first transmission unit, and thus has less intersymbol interference than a random data code sequence. Are modulated with a first shift amount having a smaller shift than the set shift amount used for modulation of the data code string, and transmitted. When the radio signal in which the first set code string is modulated in this way is received by the receiving device, the frequency deviation amount is made smaller than the set deviation amount, so before the automatic frequency adjustment in the receiving device is completed. In addition, it is easy to narrow the pass bandwidth of the IF filter. Furthermore, since the first setting code string has less intersymbol interference, the reception sensitivity of the first setting code string in the receiving apparatus is reduced even if the frequency deviation amount is smaller than the setting deviation amount used for modulation of the data code string. The risk of lowering is reduced. As a result, it is not necessary to use a dummy signal that has no meaning as a code as in the background art, so that it is possible to narrow the passband width of the IF filter of the receiving device while reducing the possibility of an increase in communication time. It becomes easy.

  The first setting code string is preferably a bit synchronization code string for bit synchronization.

  The bit synchronization code string is suitable for the first setting code string because it is transmitted before transmission of the data code string by the data transmitting unit and has regularity and little intersymbol interference.

  In the first shift signal transmission process, the first transmitter transmits all of the first setting code string using a radio signal whose frequency shift amount is the first shift amount, After the first set code string is transmitted by the first transmission unit, a frequency deviation amount from the carrier frequency is a second deviation amount that is larger than the first deviation amount and smaller than the set deviation amount. The data transmission unit further includes a second transmission unit that executes a second shift signal transmission process for transmitting at least a part of a frame synchronization code string for achieving frame synchronization using a radio signal. It is preferable that the data transmission process is executed after the frame synchronization code string is transmitted by the transmission unit.

  According to this configuration, the first setting code sequence having regularity and less intersymbol interference is modulated and transmitted by the first transmission unit with the first shift amount having a smaller shift than the data code sequence. Therefore, automatic frequency adjustment can be executed in a state in which a decrease in reception sensitivity at the receiving apparatus is reduced. Even if the transmission of the first set code sequence is completed before the automatic frequency adjustment is completed, the frame synchronization code is not random after that and therefore has less intersymbol interference than the data code sequence. Since at least a part of the sequence is modulated and transmitted by the second transmission unit with the second deviation amount smaller than the set deviation amount, without increasing the pass bandwidth required for the IF filter of the receiving apparatus, and As a result of shortening the transmission time of the first setting code string from the time required for automatic frequency adjustment without reducing the reception sensitivity of the frame synchronization code string, the time necessary for automatic frequency adjustment is ensured. For this reason, the possibility that the transmission time of the first set code string is extended and the communication time is extended is reduced.

  The first transmission unit further includes an unmodulated transmission unit that transmits the unmodulated radio signal before the first shift signal transmission process is started, and the unmodulated transmission unit transmits the unmodulated signal. The sum of the time during which the radio signal is transmitted and the execution time of the first shift signal transmission processing by the first transmitter is received based on the received radio signal at the radio receiving device that receives the radio signal. It is preferable that the time required for executing the automatic frequency adjustment for adjusting the frequency of the radio signal is set to be equal to or longer than a preset adjustment time.

  According to this configuration, after the non-modulated radio signal is transmitted by the non-modulated transmitter, the first shift signal transmission process is started by the first transmitter. Then, the sum of the time for transmitting the unmodulated radio signal and the execution time for the first shift signal transmission process is set to be equal to or longer than the adjustment time necessary for executing the automatic frequency adjustment in the radio reception apparatus. . Therefore, since the non-modulation transmission unit can shorten the time for transmitting the non-modulation radio signal to be shorter than the adjustment time, it is not necessary to continuously transmit the dummy signal during the adjustment time unlike the background art. Thereby, it is possible to reduce the possibility that the communication time is increased as compared with such background art.

  The first transmitter is a time required for executing automatic frequency adjustment for adjusting a frequency of a radio signal to be received based on the received radio signal in a radio receiver that receives the radio signal. It is preferable that the first shift signal transmission process is continued for a preset adjustment time or longer.

  According to this configuration, since the first shift signal transmission process continues until the automatic frequency adjustment is completed in the wireless reception device, the frequency shift amount is set by the data signal unit before the automatic frequency adjustment is completed. To reduce the reception sensitivity due to the lack of the pass bandwidth required for the IF filter and the reception of a data code string with large intersymbol interference before the completion of automatic frequency adjustment. The

  Further, the wireless reception in which the total of the execution time of the first shift signal transmission process by the first transmitter and the execution time of the second shift signal transmission process by the second transmitter receives the radio signal It is preferable that the time required for executing automatic frequency adjustment for adjusting the frequency of a radio signal to be received based on the received radio signal in the apparatus is set to be equal to or longer than a preset adjustment time.

  According to this configuration, since the second shift signal transmission process continues until the automatic frequency adjustment is completed in the wireless reception device, the frequency shift amount is set by the data signal unit before the completion of the automatic frequency adjustment. The reception sensitivity decreases due to a lack of pass bandwidth required for the IF filter or reception of a data code string having greater intersymbol interference than the frame synchronization code string before completion of automatic frequency adjustment. Is less likely to occur.

  Further, in the first shift signal transmission process, the first transmission unit may gradually increase the frequency shift amount of the radio signal from the first shift amount toward the set shift amount. preferable.

  According to this configuration, as the IF frequency shift is reduced by the automatic frequency adjustment in the wireless reception device and a margin is generated in the pass bandwidth of the IF filter, the first transmitter unit fills the margin of the pass bandwidth. Since the frequency shift amount of the radio signal can be gradually increased, it is possible to gradually increase the reception sensitivity of the radio reception device during the first shift signal transmission process.

  In the first deviation signal transmission process, the first transmission unit gradually increases the first deviation amount toward the second deviation amount, and the second transmission unit In the shift signal transmission process, it is preferable that the second shift amount is gradually increased toward the set shift amount.

  According to this configuration, as the IF frequency shift is reduced by the automatic frequency adjustment in the radio receiving apparatus and a margin is generated in the pass bandwidth of the IF filter, the first transmitter and the second transmitter have a margin in the pass bandwidth. Since the amount of frequency deviation of the radio signal can be gradually increased so as to fill in, the reception sensitivity of the radio reception device during the first deviation signal transmission process and the second deviation signal transmission process is gradually increased. Can be increased.

  A temperature detection unit configured to detect a temperature; and the non-modulation transmission unit sets a length of time for transmitting the non-modulation radio signal according to the temperature detected by the temperature detection unit. Is preferred.

  An oscillation signal used for modulation of a radio signal fluctuates under the influence of temperature due to the temperature characteristics of the oscillation circuit, resulting in a deviation in the frequency of the radio signal. As the frequency shift of the radio signal increases, the time required for automatic frequency adjustment in the radio reception device increases. Here, if the transmission time of an unmodulated radio signal is fixed, the first deviation is achieved even when the frequency shift due to temperature becomes maximum, that is, when the time required for automatic frequency adjustment becomes maximum. It is necessary to set the transmission time of an unmodulated radio signal so that automatic frequency adjustment is completed before the signal transmission process is completed. Then, even if the temperature condition is good and the time required for automatic frequency adjustment is short, the transmission time of the unmodulated radio signal becomes longer than the originally required time, and the communication time increases. However, according to the above configuration, the length of time for transmitting an unmodulated radio signal can be adjusted according to the temperature, so that the transmission time of the unmodulated radio signal can be shortened when the temperature condition is good. Thus, it becomes easy to shorten the communication time.

  Moreover, it is preferable to further include a temperature detection unit that detects a temperature and a deviation amount setting unit that sets the first deviation amount according to the temperature detected by the temperature detection unit.

  An oscillation signal used for modulation of a radio signal fluctuates under the influence of temperature due to the temperature characteristics of the oscillation circuit, resulting in a deviation in the frequency of the radio signal. As the frequency shift of the radio signal increases, the pass bandwidth required for the IF filter increases. Here, if the first shift amount is fixed, the IF filter passband width is set to the maximum value that may be required when the frequency shift due to temperature becomes maximum. There is a need to. Then, when the temperature condition is good and the frequency deviation is small, there is a margin in the pass band width of the IF filter. However, according to the above configuration, since the length of time for transmitting an unmodulated radio signal can be adjusted according to the temperature, the temperature condition is good, and when the IF filter has a margin in the pass bandwidth, It is possible to increase the first shift amount and improve the reception sensitivity in the wireless reception device.

A radio communication system according to the present invention includes the above-described radio transmission device and a radio reception device that receives the radio signal, and the radio reception device includes a reception unit that receives the radio signal, and a local oscillation frequency. The local oscillation unit that generates the oscillation signal of the above, the reception signal acquired by the reception unit and the oscillation signal generated by the local oscillation unit are mixed, and the reception signal is converted into an intermediate frequency to convert the intermediate frequency signal A mixing unit for generating, an intermediate frequency filter for filtering the intermediate frequency signal generated by the mixing unit, a demodulating unit for demodulating the signal filtered by the intermediate frequency filter, and the radio signal received by the receiving unit So as to reduce a difference between a reference oscillation frequency used for modulating the radio signal in the radio transmission device and the local oscillation frequency. Serial and an automatic frequency adjusting unit that adjusts a local oscillation frequency, the intermediate frequency pass band width B _IF filter, the radio signal modulation frequency f _MOD of _the set shift amount f _DEVS, the reference oscillation frequency If the reference oscillation frequency deviation, which is the maximum deviation from the design value, is Δf _TX , and the local oscillation frequency deviation, which is the maximum deviation from the design value of the local oscillation frequency, is Δf _RX , It is set to satisfy 1).

B _IF <2 × (f _MOD + f _DEVS + Δf _TX + Δf _RX ) (1)
According to this configuration, when the above-described wireless transmission device is used and the frequency deviation amount is fixed to the set deviation amount by _fDEVS as in the background art, the IF filter is obtained based on the equation (3). It is possible to improve the reception sensitivity by narrowing the pass bandwidth B _IF rather than the pass bandwidth required for. In addition, since it is not necessary to use a dummy signal having no meaning as a code, it is easy to narrow the pass band width of the IF filter in the wireless reception device while reducing the possibility of an increase in communication time.

  In addition, the wireless reception device further includes an operation handle that receives an operation instruction from a user, a switching element that opens and closes a power supply path to a load, a signal demodulated by the demodulation unit, and an operation received by the operation handle It is preferable to include a switch control unit that opens and closes the opening and closing unit according to an instruction.

  According to this configuration, in the switch system that turns on and off a load using a radio signal, the above-described radio transmission device is used as a radio transmission device that transmits a load control signal, thereby reducing the possibility of an increase in communication time. However, it becomes easy to narrow the pass band width of the IF filter in the wireless receiver.

  In the wireless transmission device and the wireless communication system configured as described above, before the data code sequence is transmitted by the data transmission unit, first, the first transmission unit has regularity, and therefore the code is more efficient than the random data code sequence. At least a part of the first set code sequence with little inter-interference is modulated and transmitted with the first shift amount having a smaller shift than the set shift amount used for the modulation of the data code sequence. When the radio signal in which the first set code string is modulated in this way is received by the receiving device, the frequency deviation amount is made smaller than the set deviation amount, so before the automatic frequency adjustment in the receiving device is completed. In addition, it is easy to narrow the pass bandwidth of the IF filter. Furthermore, since the first setting code string has less intersymbol interference, the reception sensitivity of the first setting code string in the receiving apparatus is reduced even if the frequency deviation amount is smaller than the setting deviation amount used for modulation of the data code string. The risk of lowering is reduced. As a result, it is not necessary to use a dummy signal that has no meaning as a code as in the background art, so that it is possible to narrow the passband width of the IF filter of the receiving device while reducing the possibility of an increase in communication time. It becomes easy.

  Moreover, it is possible to reduce the possibility that the power consumption will increase by reducing the possibility that the communication time will increase.

  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 an explanatory diagram illustrating an example of a wireless communication system including a wireless transmission device according to an embodiment of the present invention and a wireless reception device that receives a wireless signal transmitted from the wireless transmission device. A wireless communication system 1 illustrated in FIG. 1 includes a wireless transmission device 2 that transmits a wireless signal, and a wireless reception device 3 that functions as a switch device that blinks the illumination load LD according to the wireless signal. The wireless receiver 3 is connected in series with the illumination load LD and connected to a power source (commercial AC power source) AC. The load is not limited to the illumination load LD such as a fluorescent lamp or a fluorescent lamp electronic ballast, but may be other illumination load or a load other than the illumination load.

  An operation handle 10 is provided on the front surface of the wireless reception device 3.

  FIG. 2 is a block diagram illustrating an example of the configuration of the wireless reception device 3 illustrated in FIG. The wireless reception device 3 includes a wireless reception circuit 31, a switching element 11, a switch control unit 12, and a switch input unit 13.

  The switch input unit 13 is configured using, for example, a tact switch disposed so as to be interlocked with the operation handle 10. The switching element 11 is a switching element such as a triac, for example. The switching element 11 opens and closes a power supply path to the illumination load LD in accordance with a control signal from the switch control unit 12.

  The switch control unit 12 is configured using, for example, a microcomputer. Then, the switch control unit 12 opens and closes the switching element 11 according to the signal transmitted from the wireless transmission device 2 and received by the wireless reception circuit 31 and the on / off signal output from the switch input unit 13.

  FIG. 3 is a block diagram showing an example of the configuration of the wireless reception circuit 31 shown in FIG. 3 includes a receiving antenna RANT, a low noise amplifier LNA, an RF filter RFF, a mixer MIX (mixing unit), an IF filter IFF (intermediate frequency filter), an IF amplifier IFA, a detector DTC, and a baseband circuit unit. An RBB, an automatic frequency adjustment circuit AFC (automatic frequency adjustment unit), and a local oscillation circuit LO are provided. In this case, the reception antenna RANT, the low noise amplifier LNA, and the RF filter RFF correspond to an example of a reception unit, and the detector DTC and the baseband circuit unit RBB correspond to an example of a demodulation unit.

  A wireless signal indicating an on / off instruction of the switching element 11 is transmitted from the wireless transmission device 2 and received by the reception antenna RANT of the wireless reception circuit 31. The high frequency radio signal received by the receiving antenna RANT is amplified by the low noise amplifier LNA, and unnecessary frequency components are removed by the RF filter RFF, and then the reference oscillation frequency (local oscillation frequency) output from the local oscillation circuit LO by the mixer MIX. ) Output signal and converted to an IF signal.

  The IF signal is freed of unnecessary frequency components by the IF filter IFF, amplified by the IF amplifier IFA, further frequency-voltage converted by the detector DTC, and then transmitted to the baseband circuit unit RBB, and further the baseband circuit unit RBB. The reception data converted into the baseband in step S is output to the switch control unit 12.

  Thereby, the switch control unit 12 opens and closes the switching element 11 in accordance with the radio signal transmitted from the radio transmission device 2.

  Here, when the reference oscillation frequency of the wireless transmission device 2 and the reference oscillation frequency of the wireless reception circuit 31 are shifted from each other due to the influence of temperature, the IF frequency of the IF signal deviates from the design value. At this time, the signal frequency-voltage converted by the detector DTC is also deviated from the design value, and the reception sensitivity is lowered.

  Therefore, the output signal of the detector DTC is input to the automatic frequency adjustment circuit AFC. Then, the automatic frequency adjustment circuit AFC adjusts the local oscillation frequency of the local oscillation circuit LO to match the reference oscillation frequency of the wireless transmission device 100, and converges the IF frequency to the design value.

  FIG. 4 is a block diagram illustrating an example of the configuration of the wireless transmission device 2 illustrated in FIG. The wireless transmission device 2 illustrated in FIG. 4 includes a transmission control circuit TCC, a transmission RF circuit TRF, a reference oscillator OSC, a power amplifier PA, and a transmission antenna TANT.

  The transmission control circuit TCC includes, for example, a CPU (Central Processing Unit) that executes predetermined arithmetic processing, a ROM (Read Only Memory) that stores a predetermined control program, and a RAM (Random Access Memory) that temporarily stores data. ) And these peripheral circuits and the like. The transmission control circuit TCC functions as the bit synchronization signal transmission unit 21 (first transmission unit), the frame synchronization signal transmission unit 22, and the data transmission unit 23 by executing a control program stored in the ROM, for example. .

  Note that the transmission control circuit TCC is not limited to an example using a CPU, and may be configured using, for example, a state machine or a logic circuit.

The bit synchronization signal transmission unit 21 transmits, to the transmission RF circuit TRF, a signal S1 indicating a code string to be transmitted and a signal S2 indicating a frequency shift amount from the carrier frequency to the transmission RF circuit TRF. The transmission RF circuit TRF generates a bit synchronization code string (first setting code string) for bit synchronization using a radio signal whose frequency deviation from the carrier frequency is a predetermined first deviation f _DEV1 . At least a part is transmitted.

  After the bit synchronization code string is transmitted by the bit synchronization signal transmission unit 21, the frame synchronization signal transmission unit 22 transmits the signals S1 and S2 to the transmission RF circuit TRF, thereby obtaining frame synchronization by the transmission RF circuit TRF. For this purpose is transmitted.

After the frame synchronization code string is transmitted by the frame synchronization signal transmission unit 22, the data transmission unit 23 transmits the signals S1 and S2 to the transmission RF circuit TRF, whereby the transmission RF circuit TRF causes the frequency deviation from the carrier frequency. Utsuriryou is to transmit the data code string representing the data using a radio signal is set shift amount f _DEVS.

Here, the first deviation amount _fDEV1 is set to a deviation amount smaller than the set deviation amount _fDEVS used for transmitting the data code string.

  The reference oscillator OSC is configured by using, for example, a crystal oscillator, and outputs an oscillation signal having a reference oscillation frequency used for FM modulation to the transmission RF circuit TRF.

  The transmission RF circuit TRF subjects the signal S1 indicating the code string output from the transmission control circuit TCC to FSK modulation based on the oscillation signal output from the reference oscillator OSC, and sends the modulated signal to the power amplifier PA. Further, the transmission RF circuit TRF sets the frequency shift amount when the code string is modulated in accordance with the signal S2 output from the transmission control circuit TCC.

  The power amplifier PA amplifies the modulation signal and transmits it to the transmission antenna TANT. Then, a radio signal is radiated from the transmission antenna TANT to the space.

FIG. 5 is an explanatory diagram for explaining an example of the operation of the wireless communication system 1 shown in FIG. FIG. 5A shows a wireless signal transmitted from the wireless transmission device 2, and FIG. 5B shows an IF output from the mixer MIX to the IF filter IFF when the wireless signal is received by the wireless reception device 3. FIG. 5C shows the frequency shift amount of FSK modulation in the wireless transmission device 2, and FIG. 5D shows the IF filter IFF in the wireless transmission device 2. It shows the pass-band width B _IF needed in. 5A to 5D indicate the elapsed time t from the start of automatic frequency adjustment by the automatic frequency adjustment circuit AFC.

First, at time t = 0, a transmission trigger is generated when a person is detected by, for example, a human sensor (not shown) connected to the transmission control circuit TCC in the wireless transmission device 2. When such a transmission trigger occurs, the bit synchronization signal transmission unit 21 outputs signals S1 and S2, and a bit in which the frequency deviation f _DEV is set to the first deviation amount f _DEV1 from the transmission RF circuit TRF. The synchronization signal is transmitted during an adjustment time T _AFC that is set in advance as a time required for the automatic frequency adjustment circuit AFC of the radio reception circuit 31 to execute automatic frequency adjustment.

When this bit synchronization signal is received by the wireless receiver 3, automatic adjustment of the oscillation frequency of the local oscillation circuit LO by the automatic frequency adjustment circuit AFC is started (time t = 0). Here, assuming that the design value of the IF frequency in the wireless receiver 3 is f _IF0 and the maximum absolute value of the deviation from the design value of the IF frequency at time t is Δf _IF (t), automatic frequency adjustment is started. (T = 0), the maximum absolute value Δf _IF (0) of the deviation is Δf _TX + Δf _RX .

That is, at time t = 0, the IF frequency is in the range of f _IF0 − (Δf _TX + Δf _RX ) to f _IF0 + (Δf _TX + Δf _RX ). At this time, since the IF filter IFF needs to pass through this frequency range, the required pass bandwidth B _{IF at} time t = 0 is expressed by the following equation (5) from equation (3) (FIG. 5). 5 (d)).

B _IF ≧ 2 × (f _MOD + f _DEV1 + Δf _TX + Δf _RX ) (when t = 0) (5)
Then, along with the execution of the automatic frequency adjustment by the automatic frequency adjustment circuit AFC (with the elapse of time t), the frequency of the oscillation signal output from the local oscillation circuit LO is adjusted, and is necessary for executing the automatic frequency adjustment. after the lapse of the adjustment time _{T AFC} is the time, △ _f IF (t) is converged to substantially "0".

Here, the code length of the bit synchronization signal, a bit synchronous signal bit transmission time T _B is the time taken to transmit a is previously set to be longer than the adjustment time T _AFC.

As shown in FIG. 5 (d), the pass bandwidth B _IF required for the IF filter IFF is expressed by the following equation (6) during the time t is 0 <t <T _AFC .

B _IF ≧ 2 × (f _MOD + f _DEV1 + Δf _IF (t)) (0 <t <T _AFC ) (6)
When the adjustment time T _AFC elapses from the start of transmission of the bit synchronization signal, the bit synchronization signal transmission unit 21 changes the frequency deviation f _DEV to the set deviation amount f _{DEVS as shown} in FIG. . Then, until the bit transmission time T _B, the bit synchronization signal frequency deviation f _DEV is set shift amount f _DEVS is transmitted from the wireless transmission device 2 to the wireless receiver 3.

As a result, after the adjustment time T _AFC has elapsed, Δf _IF (t) _≈0 and f _DEV = f _DEVS , so the time t is required for the IF filter IFF in the period of t ≧ T _AFC. The passband width B _IF is represented by the following equation (7) as shown in FIG.

B _IF ≧ 2 × (f _MOD + f _DEVS ) (when t ≧ T _AFC ) (7)
When the bit transmission time _{T B} has elapsed, the frame synchronization signal transmitter 22 outputs a signal S1, S2, from the transmission RF circuit TRF, frequency shift _{f DEV} is set shift amount _{f DEVS} set frame synchronization in Send a signal.

When the transmission of the frame synchronization signal ends, the data transmission unit 23 outputs signals S1 and S2, and the data signal in which the frequency deviation f _DEV is set to the set deviation amount f _DEVS from the transmission RF circuit TRF. To send. In this case, the data signal represents, for example, a code string that instructs the switch control unit 12 to turn the switching element 11 on and off, and is generally a random code pattern.

Here, as described above, in order to achieve both high communication speed and high communication reliability, it is necessary to increase the frequency shift _fDEV . However, in the case of the same communication speed and the same frequency shift, when comparing the case where the received data is a random signal and the case of repeated bit synchronization signals of 1010. Due to the regularity of the signal, the reception sensitivity is improved because there is less intersymbol interference.

That is, even if the frequency deviation f _DEV is set to a smaller value in the regular bit synchronization signal section than in the random data signal section, it is possible to obtain reception sensitivity comparable to that in the data signal section. Therefore, _assuming that the frequency deviation f _DEV determined so as to obtain a desired reception sensitivity in the data signal section is the set deviation amount f _DEVS , a reception sensitivity equivalent to the data signal section is obtained in the bit synchronization signal section. And a first deviation amount f _DEV1 that satisfies a condition smaller than the set deviation amount f _DEVS exists. The first shift amount _{f DEV1,} such condition is satisfied first shift amount _{f DEV1} is set in advance.

Then, the pass bandwidth B _IF required for the IF filter IFF to receive the entire wireless signal is expressed by 2 × (f _MOD + f _DEV1 + Δf _TX from Equation (5) and Equation (6). + Δf _RX ) or 2 × (f _MOD + f _DEVS ), whichever is greater (FIG. 5D shows an example where the former is larger). In _{particular, 2 × (f MOD + f} DEV1 + △ f TX + △ f RX) = a so that _{2 × (f MOD + f DEVS} ), by setting the set shift amount _{f DEVS} the first shift amount _{f DEV1} The pass bandwidth of the IF filter IFF can be used most efficiently.

On the other hand, in the background art shown in FIG. 17, since the frequency shift f _DEV is fixed to the same set shift amount f _DEVS as at the time of data transmission, the pass bandwidth required for the IF filter 115 can be calculated from the equation (3). B _IF ≧ 2 × (f _MOD + f _DEVS + Δf _TX + Δf _RX ). Then, it is assumed that the pass bandwidth B _IF required for the IF filter IFF is either 2 × (f _MOD + f _DEV1 + Δf _TX + Δf _RX ) or 2 × (f _MOD + f _DEVS ). _Is also smaller than 2 × (f _MOD + f _DEVS + Δf _TX + Δf _RX ).

Therefore, the pass bandwidth B _IF required for the IF filter IFF can be set to a value satisfying the following equation (8).

B _IF <2 × (f _MOD + f _DEVS + Δf _TX + Δf _RX ) (8)
Then, the pass bandwidth _{B IF} required for the IF filter IFF, by setting so as to satisfy the equation (8), from equation (4), than the background art shown in FIG. 17, the pass band width _{B IF} The reception sensitivity SS of the wireless reception circuit 31 can be improved (reduced) by reducing the width.

  In the present embodiment, the wireless transmission device 2 and the wireless reception device 3 each represent one wireless communication system. However, either one or both of the wireless transmission device 2 and the wireless reception device 3 includes a plurality of wireless communication systems. It may be a wireless communication system.

  Since the wireless communication system 1 configured as described above can improve (reduce) the reception sensitivity SS of the wireless reception circuit 31 without using a dummy signal, the possibility of increasing the communication time due to the dummy signal is reduced. However, the pass band width of the IF filter in the wireless receiver can be narrowed.

The bit synchronization signal transmitter 21, an example of changing the adjustment time _{T AFC} timing the frequency shift _{f DEV} setting shift amount _{f DEVS,} bit synchronous signal transmission unit 21 shown in FIG. 6 as described above, in the timing of the bit transmission time _{T B} may be changed to a frequency deviation _{f DEV} set shift amount _{f DEVS.}

In this case, bit synchronization signal transmission unit 21 measures the adjustment time T _AFC, there is no need to switch the frequency shift amount during transmit bit synchronization signals, to simplify the configuration of the bit synchronization signal transmitter 21 It becomes easy.

(Second Embodiment)
Next, a radio communication system according to the second embodiment of the present invention will be described. The wireless communication system according to the second embodiment is different from the wireless communication system according to the first embodiment in that a wireless transmission device 2a is provided instead of the wireless transmission device 2. The wireless transmission device 2a is shown in FIG.

  The radio transmission apparatus 2a illustrated in FIG. 4 differs from the radio transmission apparatus 2 in operations of the bit synchronization signal transmission unit 21a and the frame synchronization signal transmission unit 22a (second transmission unit) in the transmission control circuit TCCa.

The bit synchronization signal transmission unit 21a transmits, to the transmission RF circuit TRF, a signal S1 indicating a code string to be transmitted and a signal S2 instructing a frequency shift amount from the carrier frequency to the transmission RF circuit TRF. The transmission RF circuit TRF generates a bit synchronization code string (first setting code string) for bit synchronization using a radio signal whose frequency deviation from the carrier frequency is a predetermined first deviation f _DEV1 . Send everything.

Here, the bit transmission time T _B it takes to transmit a bit synchronous signal is set to shorter than the adjustment time T _AFC time.

After the bit synchronization code string is transmitted by the bit synchronization signal transmission unit 21, the frame synchronization signal transmission unit 22a transmits the signals S1 and S2 to the transmission RF circuit TRF. The frame synchronization signal is transmitted using a radio signal having a frequency deviation amount of the second deviation amount _fDEV2 .

Here, the second deviation amount f _DEV2 is set to a value larger than the first deviation amount f _{DEV1 and} smaller than the set deviation amount f _DEVS .

  The other configuration is the same as that of the wireless transmission device 2 shown in FIG. FIG. 7 is an explanatory diagram for explaining an example of the operation of a wireless communication system using the wireless transmission device 2a and the wireless reception device 3 according to the second embodiment shown in FIG.

First, when a transmission trigger occurs at time t = 0, the bit synchronization signal transmission unit 21a outputs signals S1 and S2, and the frequency deviation f _DEV is changed from the transmission RF circuit TRF to the first deviation amount f _DEV1. The bit synchronization signal set to is transmitted.

When the elapse of bit transmission time _{T B,} the frame synchronization signal transmitting section 22a outputs a signal S1, S2, from the transmission RF circuit TRF, frequency shift _{f DEV} is set in the second shift amount _{f DEV2} The frame synchronization signal is transmitted.

Here, the frame transmission time T _F is the time taken to transmit a frame synchronizing signal, the total of the bit transmission time T _B is set to be longer than the adjustment time T _AFC. That is, the bit transmission time T _B , the frame transmission time T _F , and the adjustment time T _AFC are set in advance so that T _B <T _AFC ≦ T _B + _TF .

  As described above, since there is no intersymbol interference in the bit synchronization signal section, even if the frequency shift is set to a value smaller than that of the data signal section, it is possible to obtain reception sensitivity comparable to that of the data signal section. Is possible. Even in the frame synchronization signal, the maximum number of consecutive identical codes is limited, and the number of occurrences of 0 and 1 in the frame synchronization signal interval is almost the same, thereby reducing intersymbol interference compared to the random data signal interval. Can be small.

Accordingly, in the frame synchronization signal section, the receiving sensitivity equivalent to the bit synchronization signal section and the data signal section can be obtained, and the condition satisfying the condition that is larger than the first deviation amount f _{DEV1 and} smaller than the set deviation amount f _{DEVS is} satisfied. There is a 2 deviation amount _fDEV2 . The second shift amount _{f DEV2,} such conditions are satisfied second shift amount _{f DEV2} is set in advance.

As a result, the wireless transmission device 2a sets the frequency deviation f _DEV to the first deviation amount f _DEV1 during the period of 0 ≦ t <T _{B and} the frequency deviation during the period of T _B ≦ t <T _B + _TF. Let f _DEV be the second deviation amount f _DEV2, and let the frequency deviation f _DEV be the set deviation amount f _DEVS during the period of T _B + T _F ≦ t.

Then, the pass bandwidth B _IF required for the IF filter IFF of the wireless reception circuit 31 is given by the following equations (9) to (12) based on the equation (3).

B _IF ≧ 2 × (f _MOD + f _DEV1 + Δf _TX + Δf _RX ) (when t = 0) (9)
B _IF ≧ 2 × (f _MOD + f _DEV1 + Δf _IF (t)) (when 0 <t <T _B ) (10)
B _IF ≧ 2 × (f _MOD + f _DEV2 + Δf _IF (t)) (when T _B ≦ t <T _B + _TF ) (11)
B _IF ≧ 2 × (f _MOD + f _DEVS ) (when t ≧ T _B + _TF ) (12)

Then, the pass bandwidth B _IF required for the IF filter IFF to receive the entire wireless signal is expressed by 2 × (f _MOD + f _DEV1 + Δf _TX + from Equations (9) to (12). Δf _RX ), 2 × (f _MOD + f _DEV2 + Δf _IF (T _B )), and 2 × (f _MOD + f _DEVS ) (2 × in FIG. 7D) (F _MOD + f _DEV1 + Δf _TX + Δf _RX ) is the largest example).

In particular, 2 × (f _MOD + f _DEV1 + Δf _TX + Δf _RX ) = 2 × (f _MOD + f _DEV2 + Δf _IF (T _B )) = 2 × (f _MOD + f _DEVS ) When the 1st deviation amount f _DEV1 , the second deviation amount f _DEV2 , and the set deviation amount f _DEVS are set, the pass bandwidth of the IF filter IFF can be used most efficiently.

On the other hand, in the background art shown in FIG. 17, the pass bandwidth required for the IF filter 115 is B _IF ≧ 2 × (f _MOD + f _DEVS + Δf _TX + Δf _RX ) as described above. Then, the pass bandwidth B _IF required for the IF filter IFF is 2 × (f _MOD + f _DEV1 + Δf _TX + Δf _RX ) and 2 × (f _MOD + f _DEV2 + Δf _IF (T _B )) And 2 × (f _MOD + f _DEVS ), whichever is the maximum, becomes smaller than 2 × (f _MOD + f _DEVS + Δf _TX + Δf _RX ).

Therefore, the pass bandwidth B _IF required for the IF filter IFF can be set to a value satisfying the above equation (8). Then, by setting the pass bandwidth B _IF required for the IF filter IFF so as to satisfy the equation (8), the reception of the radio reception circuit 31 can be obtained from the equation (4) than the background art shown in FIG. The sensitivity SS can be improved (reduced).

Note that the frame synchronization signal transmission unit 22a has shown the example in which the frequency shift f _{DEV is set} to the second shift amount f _DEV2 for the entire section of the frame synchronization signal, but the frequency shift f _DEV at the timing of the adjustment time T _{AFC. May} be changed from the second deviation amount _fDEV2 to the set deviation amount _fDEVS .

  Further, in the present embodiment, the wireless transmission device 2a and the wireless reception device 3 each represent one wireless communication system, but either one or both of the wireless transmission device 2a and the wireless reception device 3 are plural. It may be a wireless communication system.

Or a wireless communication system configured as described, the bit transmission time T _B, it is possible to shorter adjustment time T _AFC time, is possible to shorten the length of the bit synchronization signal in order to shorten communication time Easy.

Further, if the response of the automatic frequency adjustment circuit unit AFC is too early, when the same code continues in the data section, the frequency adjustment is executed in this code portion, and the IF frequency may be shifted. Therefore, the response time of the automatic frequency adjustment circuit unit AFC needs to be long (the time constant is large) so that the IF frequency does not deviate when the same code that can occur in the communication protocol is maximum. The wireless transmission device 2a, as shown in FIG. 7, since the adjustment time T _AFC can be set longer than the bit transmission time T _B, for adjusting the response time of the automatic frequency adjustment circuit AFC The degree of freedom can be increased.

  Since the reception sensitivity SS of the wireless reception circuit 31 can be improved (decreased) without using a dummy signal, it is possible to pass the IF filter in the wireless reception device while reducing the possibility of an increase in communication time due to the dummy signal. Bandwidth can be reduced.

(Third embodiment)
Next, a radio communication system according to the third embodiment of the present invention will be described. The wireless communication system according to the third embodiment is different from the wireless communication system according to the first embodiment in that a wireless transmission device 2b is provided instead of the wireless transmission device 2. The wireless transmission device 2b is illustrated in FIG.

  4 differs from the wireless transmission device 2 in the operation of the bit synchronization signal transmission unit 21b in the transmission control circuit TCCb. The frame synchronization signal transmission unit 22b operates in the same manner as the frame synchronization signal transmission unit 22.

By transmitting the signals S1 and S2 to the transmission RF circuit TRF, the bit synchronization signal transmission unit 21b changes the frequency deviation f _DEV from the first deviation amount f _DEV1 to the set deviation amount f _DEVS by the transmission RF circuit TRF. The bit synchronization signal is transmitted while being gradually increased toward. At this time, the bit synchronization signal transmission section 21b, for example, after the elapse of the adjustment time _{T AFC} from the time t = 0, so that the frequency shift _{f DEV} is set shift amount _{f DEVS,} increasing the frequency deviation _{f DEV} It is supposed to let you.

  Since the other configuration is the same as that of the wireless transmission device 2 shown in FIG. 4, the description thereof is omitted, and the operation of the present embodiment will be described below. FIG. 8 is an explanatory diagram for explaining an example of the operation of a wireless communication system using the wireless transmission device 2b and the wireless reception device 3 according to the third embodiment shown in FIG.

As shown in FIG. 8C, when the frequency deviation f _DEV at time t is _defined as frequency deviation f _DEV (t), when time t = 0, f _DEV (0) = f _DEV1 , time t = T _AFC Then, f _DEV (T _AFC ) = f _DEVS .

In the interval of 0 <t <T _AFC , Δf _IF (t) gradually decreases and converges to 0 by the operation of the automatic frequency adjustment circuit AFC, so that the pass band required for the IF filter IFF The frequency shift f _DEV (t) can be increased without increasing the width B _IF .

Therefore, the bit synchronous signal transmission unit 21b, so as to satisfy the equation (13) below, by increasing gradually the frequency shift _{f DEV,} frequency deviation _{f DEV} to adjust time _{T AFC} has passed the The reception sensitivity of the bit synchronization signal can be increased as compared with the case where the shift amount is fixed at _fDEV1 .

2 × (f _MOD + f _DEV (t) + Δf _IF (t)) ≦ 2 × (f _MOD + f _DEV1 + Δf _TX + Δf _RX ) (13)
In the present embodiment, the wireless transmission device 2b and the wireless reception device 3 each represent one wireless communication system. However, either one or both of the wireless transmission device 2b and the wireless reception device 3 includes a plurality of wireless communication devices. It may be a wireless communication system.

The wireless communication system configured as described above can increase the reception sensitivity of the bit synchronization signal by continuously changing the frequency shift f _DEV (t).

(Fourth embodiment)
Next, a radio communication system according to the fourth embodiment of the present invention is described. The wireless communication system according to the fourth embodiment is different from the wireless communication system according to the second embodiment in that a wireless transmission device 2c is provided instead of the wireless transmission device 2a. The wireless transmission device 2c is illustrated in FIG. 4 like the wireless transmission device 2a.

  The radio transmission device 2c shown in FIG. 4 is different from the radio transmission device 2a shown in FIG. 7 in the operations of the bit synchronization signal transmission unit 21c and the frame synchronization signal transmission unit 22c in the transmission control circuit TCCc.

The bit synchronization signal transmission unit 21c transmits the signals S1 and S2 to the transmission RF circuit TRF, so that the transmission RF circuit TRF changes the frequency deviation f _DEV from the first deviation amount f _DEV1 to the second deviation amount f. _The bit synchronization signal is transmitted while gradually increasing toward _DEV2 . At this time, the bit synchronization signal transmission unit 21c, for example, after a bit transmission time _{T B} from the time t = 0, so that the frequency shift _{f DEV} is a second shift amount _{f DEV2,} the frequency shift _{f DEV} Is to increase.

The frame synchronization signal transmission unit 22c transmits the signals S1 and S2 to the transmission RF circuit TRF, so that the transmission RF circuit TRF changes the frequency deviation f _DEV from the second deviation amount f _DEV2 to the set deviation amount f _DEVS. The frame synchronization signal is transmitted while gradually increasing toward. At this time, the frame synchronization signal transmission unit 22c is configured so that the frequency deviation f _DEV becomes the set deviation amount f _DEVS within the transmission period of the frame synchronization signal, for example, after the adjustment time T _AFC has elapsed from time t = 0. The frequency deviation f _DEV is increased.

  Since other configurations are the same as those of the wireless transmission device 2a shown in FIG. 4, the description thereof will be omitted, and the operation of the present embodiment will be described below. FIG. 9 is an explanatory diagram for explaining an example of the operation of the wireless communication system using the wireless transmission device 2c and the wireless reception device 3 according to the fourth embodiment shown in FIG.

As shown in FIG. 9C, when the frequency deviation f _DEV at time t is _defined as frequency deviation f _DEV (t), when time t = 0, f _DEV (0) = f _DEV1 and time t = T _B F _DEV (T _B ) = f _DEV2 , and when time t = T _AFC , f _DEV (T _AFC ) = f _DEVS .

The increase in 0 <t _{<T B} of the section, by the operation of the automatic frequency adjustment circuit AFC, since △ _f IF (t) gradually decreases, the passband width _{B IF} required for the IF filter IFF It is possible to increase the frequency shift f _DEV (t) without causing the change.

Accordingly, the bit synchronization signal transmission unit 21c, so as to satisfy the above equation (13), by increasing gradually the frequency shift _{f DEV,} frequency polarized until adjustment time _{T AFC} and bit transmission time _{T B} has elapsed shift f _DEV is possible to increase the reception sensitivity of the bit synchronization signal as compared with a case that is fixed to the first shift amount f _DEV1.

Further, in the section of T _B <t <T _AFC , Δf _IF (t) gradually decreases and converges to 0 by the operation of the automatic frequency adjustment circuit AFC, so that the passage required for the IF filter IFF The frequency shift f _DEV (t) can be increased without increasing the bandwidth B _IF .

Therefore, the frame synchronization signal transmission unit 22c gradually increases the frequency deviation f _DEV so as to satisfy the following equation (14), so that the frequency deviation f _DEV is the second during the frame synchronization signal transmission period. The reception sensitivity of the frame synchronization signal can be increased as compared with the case where the deviation amount f _DEV2 is fixed.

2 × (f _MOD + f _DEV (t) + Δf _IF (t)) ≦ 2 × (f _MOD + f _DEV2 + Δf _TX + Δf _RX ) (14)
In the present embodiment, the wireless transmission device 2c and the wireless reception device 3 each represent one wireless communication system. However, either one or both of the wireless transmission device 2c and the wireless reception device 3 include a plurality of wireless communication devices. It may be a wireless communication system.

The wireless communication system configured as described above receives the bit synchronization signal and the frame synchronization signal by continuously changing the frequency shift f _DEV (t) during the transmission period of the bit synchronization signal and the frame synchronization signal. Sensitivity can be increased.

(Fifth embodiment)
Next, a radio communication system according to the fifth embodiment of the present invention is described. The wireless communication system according to the fifth embodiment is different from the wireless communication system according to the first embodiment in that a wireless transmission device 2d is provided instead of the wireless transmission device 2.

  FIG. 10 is a block diagram illustrating an example of a configuration of a wireless transmission device 2d according to the fifth embodiment. The wireless transmission device 2d illustrated in FIG. 10 differs from the wireless transmission device 2 illustrated in FIG. 4 in that the transmission control circuit TCCd further includes an unmodulated signal transmission unit 25 (unmodulated transmission unit).

  The unmodulated signal transmission unit 25 causes the transmission RF circuit TRF to transmit an unmodulated signal, that is, a signal having a carrier frequency, as a dummy signal before the bit synchronization signal transmission unit 21 starts transmitting the bit synchronization signal.

Further, when the time for transmission of the dummy signal by an unmodulated signal transmitting unit 25 and the dummy transmission time T _D, the transmission of the bit synchronization signal at the first shift amount f _DEV1 by the bit synchronization signal transmission unit 21 is executed the sum of the time and the dummy transmission time T _D is set to more than the adjustment time T _AFC. The dummy transmission time _{T D} is shorter than the adjusting time _{T AFC.}

  Since the other configuration is the same as that of the wireless transmission device 2 shown in FIG. 4, the description thereof is omitted, and the operation of the present embodiment will be described below. FIG. 11 is an explanatory diagram for explaining an example of an operation of a wireless communication system using the wireless transmission device 2d and the wireless reception device 3 illustrated in FIG. In FIG. 11, the time t = 0 is set as the start time of the dummy signal by the unmodulated signal transmission unit 25.

Since the unmodulated dummy signal has no spectrum spread due to modulation, the pass bandwidth B _IF required for the IF filter IFF to receive the dummy signal in the wireless reception circuit 31 is 2 × (Δf _TX + Δ f _RX ).

Thus, the radio transmission device 2d is a zero frequency shift _{f DEV} in a period of 0 ≦ t _{<T D.} When the dummy signal is received by the wireless reception circuit 31, Δf _IF (t) gradually decreases due to the operation of the automatic frequency adjustment circuit AFC.

When the transmission of the dummy signal dummy transmission time T _D has elapsed is completed, the transmission of the bit synchronization signal by the bit synchronization signal transmitter 21 is started by the first shift amount f _DEV1.

Then, the pass bandwidth B _IF required for the IF filter IFF of the wireless reception circuit 31 is given by the following equations (15) to (18) based on the equation (3).

B _IF ≧ 2 × (Δf _TX + Δf _RX ) (when t = 0) (15)
_{B IF ≧ 2 × △ f IF} (t) (0 <t < the case of _{T D)} ··· (16)
B _IF ≧ 2 × (f _MOD + f _DEV1 + Δf _IF (t)) (when T _D ≦ t <T _D + T _B ) (17)
B _IF ≧ 2 × (f _MOD + f _DEVS ) (when t ≧ T _D + T _B ) (18).

Then, the pass bandwidth B _IF required for the IF filter IFF to receive the entire radio signal is expressed by 2 × (Δf _TX + Δf _RX ), from Equations (15) to (18), 2 × (f _MOD + f _DEV1 + Δf _IF (T _D )) and 2 × (f _MOD + f _DEVS ) (in FIG. 11D, 2 × (Δf _TX + Δf _RX ) shows the largest example).

In particular, the first deviation amount f so that 2 × (Δf _TX + Δf _RX ) = 2 × (f _MOD + f _DEV1 + Δf _IF (T _D )) = 2 × (f _MOD + f _DEVS ) _DEV1, setting shift amount _{f DEVS,} and setting the dummy transmission time _{T D,} it is possible to use a passband width of the IF filter IFF most efficiently.

Thus, in the background art shown in FIG. 18, for at least the adjustment time T _AFC, it has been necessary to continue to transmit a dummy signal, a radio transmission device 2d shown in FIG. 10, the dummy transmission time T _D of the adjustment time T Since it can be made shorter than _AFC, it becomes easier to narrow the pass bandwidth of the IF filter IFF in the wireless reception circuit 31 while reducing the possibility of an increase in communication time as compared with the background art shown in FIG.

  In the present embodiment, the wireless transmission device 2d and the wireless reception device 3 each represent one wireless communication system. However, either one or both of the wireless transmission device 2d and the wireless reception device 3 includes a plurality of wireless communication systems. It may be a wireless communication system.

  Further, the unmodulated signal transmission unit 25 may be provided in the transmission control circuits TCCa, TCCb, and TCCc in the wireless transmission devices 2a, 2b, and 2c.

(Sixth embodiment)
Next, a radio communication system according to the sixth embodiment of the present invention is described. The wireless communication system according to the sixth embodiment is different from the wireless communication system according to the fifth embodiment in that a wireless transmission device 2e is provided instead of the wireless transmission device 2d.

  FIG. 12 is a block diagram illustrating an example of a configuration of the wireless transmission device 2e according to the sixth embodiment. The wireless transmission device 2e shown in FIG. 12 differs from the wireless transmission device 2d shown in FIG. 10 in that it further includes a temperature sensor TS (temperature detection unit), and the transmission control circuit TCCd further includes a deviation amount setting unit 26. Different. Further, the operation of the non-modulated signal transmission unit 25e is different.

  The temperature sensor TS is a temperature sensor that detects the temperature of the wireless transmission device 2d, particularly the temperature of the reference oscillator OSC.

Unmodulated signal transmitting unit 25e, in response to the temperature detected by the temperature sensor TS, sets the length of the dummy transmission time T _D.

The deviation amount setting unit 26 sets the first deviation amount _fDEV1 and the set deviation amount _fDEVS according to the temperature detected by the temperature sensor TS. The set deviation amount _fDEVS may be a fixed value.

  Since the other configuration is the same as that of the wireless transmission device 2d shown in FIG. 10, the description thereof will be omitted, and the operation of this embodiment will be described below. FIG. 13 is an explanatory diagram for explaining an example of the operation of the wireless communication system using the wireless transmission device 2e and the wireless reception device 3 illustrated in FIG. In FIG. 13, the time when the dummy signal is started by the non-modulated signal transmitter 25e is set to time t = 0.

In general, the influence of temperature is dominant as a factor that fluctuates the oscillation frequency of the reference oscillator OSC. Therefore, when the temperature of the reference oscillator OSC detected by the temperature sensor TS is X, the reference oscillation frequency deviation Δf _TX can be expressed as Δf _TX (X) as a function of the temperature X.

Therefore, the deviation amount setting unit 26 increases the first deviation amount f _DEV1 , as the absolute value of Δf _TX (X) increases (that is, as the absolute value of the reference oscillation frequency deviation Δf _TX increases). and by reducing the set shift amount _{f DEVS,} intermediate frequency is adjusted to fit within the IF filter IFF pass bandwidth _{B IF.} Further, non-modulated signal transmitting unit 25e is, △ f _TX absolute value becomes larger of _(X), by increasing the dummy transmission time T _D, allowing time to automatic frequency adjustment by the automatic frequency adjustment circuit AFC It is like that.

Further, the deviation amount setting unit 26 and the unmodulated signal transmission unit 25e are 2 × (Δf _TX (X) + Δf _RX ) = 2 × (Δf _TX + Δf _RX + f _MOD + f _DEV1 ) = 2 ×. _(f MOD _{+ f DEVS)} and such that the first shift amount _{f DEV1,} setting shift amount _{f DEVS,} and setting the dummy transmission time _{T D,} utilizing pass bandwidth of the IF filter IFF most efficiently be able to. In this case, an unmodulated signal transmitting unit 25e is, △ _{f TX} or, as the sum between the predicted value and △ _{f TX} preset △ _{f RX} is high, to increase the dummy transmission time _{T D.}

By the way, in the wireless transmission device 2d shown in FIG. 10, since the deviation Δf _TX is the maximum value when the influence of the temperature is taken into consideration, even if the deviation Δf _TX is actually a small temperature, the deviation Δ The first deviation amount f _DEV1 is set to a small value so that the intermediate frequency falls within the pass bandwidth B _IF even when f _TX becomes maximum.

On the other hand, in the wireless transmission device 2e shown in FIG. 12, since the first deviation amount f _DEV1 is set according to Δf _TX (X) considering the influence of temperature, at a temperature at which the deviation Δf _TX becomes small, Accordingly, by increasing the first deviation amount f _DEV1 , the pass bandwidth B _IF can be used without waste. As a result, it is possible to improve the reception sensitivity of the bit synchronization signal compared to the wireless transmission device 2d shown in FIG.

In the wireless transmission device 2d shown in FIG. 10, even if the deviation Δf _TX is the maximum value when the influence of temperature is taken into account, the automatic frequency adjustment circuit AFC sets Δf _IF (t) to substantially “0”. as can be converged, because it is necessary to set the dummy transmission time T _D, even at a temperature deviation △ f _TX is reduced, necessary to the dummy transmission time T _D to the combined time worst condition There is.

On the other hand, in the wireless transmission device 2e shown in FIG. 12, in consideration of the influence of temperature △ according to _f TX (X), △ _f as TX (X) is reduced, the dummy transmission time _{T D} is short, the temperature conditions is when good, it is possible to shorten the communication time than a radio transmission device 2d to shorten the dummy transmission time T _D.

(Seventh embodiment)
Next, a radio communication system according to the seventh embodiment of the present invention is described. The wireless communication system according to the seventh embodiment is different from the wireless communication system according to the first embodiment in that a wireless transmission device 2f is provided instead of the wireless transmission device 2.

  FIG. 14 is a block diagram showing an example of a configuration of a wireless transmission device 2f according to the seventh embodiment of the present invention. The wireless transmission device 2f illustrated in FIG. 14 differs from the wireless transmission device 2 illustrated in FIG. 4 in that it further includes a temperature sensor TS, and in that the transmission control circuit TCCf further includes a deviation amount setting unit 26.

  Since the other configuration is the same as that of the wireless transmission device 2 shown in FIG. 4, the description thereof is omitted, and the operation of the present embodiment will be described below. FIG. 15 is an explanatory diagram for explaining an example of an operation of a wireless communication system using the wireless transmission device 2f and the wireless reception device 3 illustrated in FIG.

In general, the influence of temperature is dominant as a factor that fluctuates the oscillation frequency of the reference oscillator OSC. Therefore, when the temperature of the reference oscillator OSC detected by the temperature sensor TS is X, the reference oscillation frequency deviation Δf _TX can be expressed as Δf _TX (X) as a function of the temperature X.

Therefore, the deviation amount setting unit 26 reduces the first deviation amount f _DEV1 as ΔF _TX (X) increases (that is, the temperature at which the reference oscillation frequency deviation Δf _TX increases). The frequency is adjusted so as to be within the IF filter IFF pass bandwidth B _IF .

Here, the deviation amount setting unit 26 sets the first deviation amount f _DEV1 (X) at the temperature X so that (Δf _TX + f _DEV1 (X)) becomes constant, so that the temperature As a result, the optimum first shift amount f _DEV1 (X) can be set according to the above, and as a result, the reception sensitivity of the bit synchronization signal can be improved as compared with the wireless transmission device 2 shown in FIG.

  Note that the function may be expressed by a functional expression, for example, and may be expressed by using a data table, for example.

It is explanatory drawing which shows an example of the radio | wireless communications system provided with the radio | wireless transmitter which concerns on one Embodiment of this invention, and the radio | wireless receiver which receives the radio signal transmitted from this radio transmitter. It is a block diagram which shows an example of a structure of the radio | wireless receiving apparatus shown in FIG. FIG. 3 is a block diagram illustrating an example of a configuration of a wireless reception circuit illustrated in FIG. 2. It is a block diagram which shows an example of a structure of the radio | wireless transmitter shown in FIG. FIG. 3 is an explanatory diagram for explaining an example of an operation of the wireless communication system shown in FIG. 1. It is explanatory drawing for demonstrating the modification of the operation | movement shown in FIG. It is explanatory drawing for demonstrating an example of operation | movement of the radio | wireless communications system using the radio | wireless transmitter which concerns on 2nd Embodiment. It is explanatory drawing for demonstrating an example of operation | movement of the radio | wireless communications system using the radio | wireless transmitter which concerns on 3rd Embodiment. It is explanatory drawing for demonstrating an example of operation | movement of the radio | wireless communications system using the radio | wireless transmitter which concerns on 4th Embodiment. It is a block diagram which shows an example of a structure of the radio | wireless transmitter which concerns on 5th Embodiment. It is explanatory drawing for demonstrating an example of operation | movement of the radio | wireless communications system using the radio | wireless transmitter shown in FIG. It is a block diagram which shows an example of a structure of the radio | wireless transmitter which concerns on 6th Embodiment. It is explanatory drawing for demonstrating an example of operation | movement of the radio | wireless communications system using the radio | wireless transmitter shown in FIG. It is a block diagram which shows an example of a structure of the wireless transmission device which concerns on 7th Embodiment of this invention. It is explanatory drawing for demonstrating an example of operation | movement of the radio | wireless communications system using the radio | wireless transmitter shown in FIG. It is a block diagram which shows the structure of the radio | wireless communications system which concerns on background art. It is explanatory drawing which shows an example of operation | movement of the radio | wireless communications system which concerns on background art. It is explanatory drawing which shows another example of operation | movement of the radio | wireless communications system which concerns on background art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Radio | wireless communications system 2, 2a, 2b, 2c, 2d, 2e, 2f Wireless transmitter 3 Wireless receiver 10 Operation handle 11 Switching element 12 Switch control part 13 Switch input part 21, 21a, 21b, 21c Bit synchronous signal transmission part 22, 22a, 22b, 22c Frame synchronization signal transmission unit 23 Data transmission unit 25, 25e Unmodulated signal transmission unit 26 Deviation amount setting unit 31 Radio reception circuit B _IF pass bandwidth AFC automatic frequency adjustment circuit DTC detector IFA IF amplifier IFF IF filter LNA low noise amplifier LO local oscillator MIX mixer OSC reference oscillator PA power amplifier RANT receiving antenna RBB baseband circuit unit RFF RF filter SS receiving sensitivity TANT transmitting antennas T _AFC adjustment time T _B bit transmission time T C, TCCa, TCCb, TCCc, TCCd, TCCe, TCCf transmission control circuit T _D dummy transmission time T _F frame transmission time TRF transmission control circuit TS Temperature sensor f _DEV frequency deviation f _DEV1 first shift amount f _DEV2 second polarized Utsuriryou f _DEVS set shift amount f _MOD modulation frequency △ _{f TX} reference oscillation frequency deviation △ _{f RX} local oscillator frequency deviation

Claims (12)

A wireless transmitter that modulates the frequency of a radio signal by shifting it from a carrier frequency,
First shift signal transmission for transmitting at least a part of a first set code sequence having a regularity set in advance using a radio signal having a frequency shift amount from the carrier frequency being a predetermined first shift amount A first transmission unit for executing processing;
After the first set code string is transmitted by the first transmitter, a radio signal having a set deviation amount in which a frequency deviation amount from the carrier frequency is set to a value larger than the first deviation amount A wireless transmission apparatus comprising: a data transmission unit that performs data transmission processing for transmitting a data code string representing data using the data transmission process. The first setting code string is:
The wireless transmission device according to claim 1, wherein the wireless transmission device is a bit synchronization code string for bit synchronization. The first transmitter is
In the first deviation signal transmission process, the entire first setting code string is transmitted using a radio signal whose frequency deviation amount is the first deviation amount,
After the first set code string is transmitted by the first transmission unit, a frequency deviation amount from the carrier frequency is a second deviation amount that is larger than the first deviation amount and smaller than the set deviation amount. A second transmission unit for executing a second shift signal transmission process for transmitting at least a part of a frame synchronization code string for achieving frame synchronization using a radio signal;
The data transmitter is
3. The wireless transmission device according to claim 1, wherein the data transmission process is executed after the frame synchronization code string is transmitted by the second transmission unit. 4. Before the first shift signal transmission processing is started by the first transmission unit, further comprising an unmodulated transmission unit that transmits the unmodulated radio signal;
In the radio receiving apparatus that receives the radio signal, the sum of the time during which the non-modulated radio signal is transmitted by the non-modulated transmitter and the execution time of the first shift signal transmission processing by the first transmitter The time required for executing automatic frequency adjustment for adjusting the frequency of a radio signal to be received based on the received radio signal is set to be equal to or longer than a preset adjustment time. Item 3. The wireless transmission device according to Item 1 or 2. The first transmitter is
More than the adjustment time set in advance as the time required to execute automatic frequency adjustment for adjusting the frequency of the radio signal to be received based on the received radio signal in the radio reception device that receives the radio signal, The wireless transmission device according to claim 1, wherein the first shift signal transmission process is continued. In the radio reception apparatus that receives the radio signal, a sum of an execution time of the first shift signal transmission process by the first transmitter and an execution time of the second shift signal transmission process by the second transmitter The time required for executing automatic frequency adjustment for adjusting the frequency of a radio signal to be received based on the received radio signal is set to be equal to or longer than a preset adjustment time. Item 4. The wireless transmission device according to Item 3. The first transmitter is
3. The frequency shift amount of the radio signal is gradually increased from the first shift amount toward the set shift amount in the first shift signal transmission process. 4. Wireless transmitter. The first transmitter is
In the first deviation signal transmission process, the first deviation amount is gradually increased toward the second deviation amount,
The second transmitter is
The wireless transmission device according to claim 3 or 6, wherein, in the second shift signal transmission process, the second shift amount is gradually increased toward the set shift amount. A temperature detection unit for detecting the temperature;
The unmodulated transmitter is
The wireless transmission device according to claim 4, wherein a length of time for transmitting the unmodulated wireless signal is set according to the temperature detected by the temperature detection unit. A temperature detector for detecting the temperature;
The wireless transmission according to any one of claims 1 to 9, further comprising a deviation amount setting unit that sets the first deviation amount according to the temperature detected by the temperature detection unit. apparatus. The wireless transmission device according to any one of claims 1 to 10,
A wireless receiving device for receiving the wireless signal;
The wireless receiver is
A receiver for receiving the radio signal;
A local oscillation unit for generating an oscillation signal having a local oscillation frequency;
Mixing a reception signal acquired by the reception unit and an oscillation signal generated by the local oscillation unit, converting the reception signal to an intermediate frequency to generate an intermediate frequency signal; and
An intermediate frequency filter for filtering the intermediate frequency signal generated by the mixing unit;
A demodulator for demodulating the signal filtered by the intermediate frequency filter;
Based on the radio signal received by the receiver, the local oscillation frequency is reduced so as to reduce a difference between a reference oscillation frequency used for modulating the radio signal in the radio transmission device and the local oscillation frequency. An automatic frequency adjustment unit to adjust,
The intermediate frequency pass band width B _IF filter, the radio signal modulation frequency f _MOD of _the set shift amount f _DEVS, the reference oscillation frequency deviation is the maximum value of the deviation from the design value of the reference oscillation frequency the △ f _TX, the local oscillation when the frequency of the local oscillator frequency deviation is the maximum value of the deviation from a design value △ and f _RX, it B _IF <2 are set to satisfy equation (1) below × (f _MOD + f _DEVS + Δf _TX + Δf _RX ) (1)
A wireless communication system. The wireless receiving device further includes:
An operation handle for accepting user operation instructions;
A switching element that opens and closes a power supply path to the load;
The wireless communication system according to claim 11, further comprising: a switch control unit that opens and closes the opening / closing unit according to a signal demodulated by the demodulation unit and an operation instruction received by the operation handle.

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