JP5861084B2 - Wireless circuit and lighting control system - Google Patents

Description

  The present invention relates to wireless communication, and more particularly to a technique for generating a signal having a specific frequency.

Conventionally, there are various modulation methods in wireless communication. For example, a direct quadrature modulation system or a VCO (Voltage Controlled Oscillator) direct modulation system.
In the direct quadrature modulation system, an I (In-phase) signal (in-phase signal) and a Q (Quadrature) signal (orthogonal signal) that is 90 degrees out of phase with the I signal are generated by a modulator. An analog conversion circuit (DAC: Digital to Analog Converter) converts a digital signal into an analog signal and removes unnecessary components to perform orthogonal conversion. When performing orthogonal transformation, a high-frequency signal for each signal (I signal, Q signal) is generated by a synthesizer including a PLL (Phase-locked loop) and a VCO.

  FIG. 12 also shows a radio circuit 2000 that uses the VCO direct modulation scheme. In the radio circuit 2000 using the VCO direct modulation method, first, an I signal is generated by the modulator 2001. A synthesizer 2002 having a PLL 2010 and a VCO 2011 converts the generated I signal into a high-frequency signal, and then the signal level is amplified by a power amplifier (PA) 2003 and a low-pass filter (LPF) 2004, and unnecessary noise is generated. Is removed and transmission is performed (see Patent Document 1).

JP 2005-94193 A

In any of the above systems, a synthesizer is necessary. The area occupied by the synthesizer in the radio circuit is very large. For example, the ratio of the synthesizer 2002 in the radio circuit 2000 is as shown in FIG. Therefore, it is a major obstacle to miniaturization of the radio circuit.
Therefore, an object of the present invention is to provide a radio circuit and a lighting control system that can generate a signal to be transmitted without using a synthesizer and can be downsized.

  In order to achieve the above object, the present invention provides a radio circuit, a signal generation unit that generates a modulation signal from a signal indicating data to be transmitted, and a frequency conversion that converts the frequency of the modulation signal into an intermediate frequency. A signal conversion unit that converts the modulated signal converted to the intermediate frequency into an analog signal, and a frequency that is an integer multiple of the sampling frequency of the signal conversion unit when the signal conversion unit performs the conversion. Of the image components appearing apart by the intermediate frequency, a filter for filtering an image component belonging to a specific high frequency band, a signal amplifying unit for amplifying the image component filtered by the filter, and the signal amplifying unit And a transmitter for transmitting the image component amplified in step (a).

Here, a frequency of an image component belonging to the specific frequency band is a first frequency, and the intermediate frequency is an integer multiple of the first frequency and the sampling frequency, and a second frequency closest to the first frequency. It is good also as a difference value.
Here, the image component belonging to the specific frequency band is in a phase opposite to the phase of the modulation signal converted to the intermediate frequency, and the radio circuit further includes the signal conversion unit prior to the conversion. In addition, a phase inversion unit that inverts the phase of the modulated signal converted to the intermediate frequency may be provided.

Here, the wireless circuit further complements the image component so that amplitude distortion of the image component belonging to the one frequency band becomes flat prior to the conversion by the signal conversion unit. A part may be provided.
Here, the wireless circuit may be provided in a wireless transceiver that performs wireless communication.
Moreover, this invention is an illumination control system which consists of one or more lighting fixtures and the control apparatus which controls the said one or more lighting fixtures by radio | wireless, Comprising: The said control device is from the control signal which concerns on control of a lighting fixture. A signal generation unit that generates a modulation signal, a frequency conversion unit that converts the frequency of the modulation signal into an intermediate frequency, a signal conversion unit that converts the modulation signal converted into the intermediate frequency into an analog signal, and the signal Filtering out image components belonging to a specific high frequency band from among image components appearing above and below the frequency every integer multiple of the sampling frequency of the signal conversion unit at the time of the conversion by the conversion unit. A filter, a signal amplifying unit for amplifying the image component filtered by the filter, and a transmission for transmitting the image component amplified by the signal amplifying unit. Each of the one or more lighting fixtures receives the image component, demodulates the received image component to generate the control signal, and controls lighting based on the generated control signal. It is characterized by performing.

  According to the above configuration, since the radio circuit generates a signal to be transmitted using the image component, a synthesizer is not necessary. Therefore, the wireless circuit can be reduced in size.

1 is a diagram illustrating a configuration of a radio circuit 1. FIG. It is a figure explaining the Sinc function response in the analog signal output from DAC12. It is a figure explaining transition of a signal level. 3 is a flowchart showing processing of the radio circuit 1. It is a figure explaining the amplitude and phase in a Sinc function response. It is a figure explaining the relationship between the phase of the signal of an intermediate frequency, and the phase of a 7th image component. It is a figure which shows the structure of the radio | wireless circuit 1a. It is a figure which shows the structure of the radio | wireless circuit 1b. It is a figure explaining amendment of amplitude distortion. 2 is a diagram illustrating a configuration of a transceiver 100. FIG. It is a figure which shows the structure of the illumination control system 1000. FIG. It is a figure which shows the structure of the radio | wireless circuit 2000 using the conventional VCO direct modulation system. It is a figure explaining the ratio for which a synthesizer accounts in the conventional radio | wireless circuit.

Hereinafter, a wireless circuit 1 according to an embodiment of the present invention will be described with reference to the drawings.
1. 1. Embodiment 1.1 Configuration A radio circuit 1 according to an embodiment of the present invention generates and outputs a signal having a frequency to be used in radio communication without using a synthesizer.

  As shown in FIG. 1, the radio circuit 1 includes a modulator 10, a frequency converter 11, a digital-to-analog converter circuit (DAC) 12, a band-pass filter (BPF: Band-pass filter) 13, and signal amplification. The unit 14 includes a low-pass filter (LPF) 15 and an antenna 16.

(1) Modulator 10
The modulator 10 modulates a signal of data to be transmitted to generate a modulated signal that is a digital signal.
Specifically, the modulator 10 modulates a signal of data to be transmitted to generate an I signal (in-phase signal) and a Q signal (quadrature signal) that is 90 degrees out of phase with the I signal. Here, a set of the I signal and the Q signal is referred to as a modulation signal.

(2) Frequency converter 11
The frequency conversion unit 11 converts the frequency of the modulation signal generated by the modulator 10 into an intermediate frequency, and includes an orthogonal conversion unit 21 and a ROM table 22 as shown in FIG.
The ROM table 22 stores information for converting each frequency of the I signal and the Q signal into an intermediate frequency.

  The orthogonal transform unit 21 transforms the modulation signal generated by the modulator 10 into an intermediate frequency based on the information stored in the ROM table 22. Specifically, the orthogonal transform unit 21 converts each frequency of the I signal and the Q signal generated by the modulator 10 based on the information in the ROM table 22 to an intermediate frequency, and converts the converted I to the intermediate frequency. By adding the signal and the Q signal, a waveform of a modulation signal at an intermediate frequency (IF) is obtained. The modulation signal of the intermediate frequency is also called an IF signal.

(3) DAC12
The DAC 12 is a circuit that converts a digital signal, which is a modulation signal having an intermediate frequency obtained by the frequency converter 11 based on the sampling frequency (fs: 50 MHz), into an analog signal. Here, the sampling frequency (fs) is the frequency of an external crystal oscillator, and the DAC 12 operates at this frequency.

  Normally, when an analog signal converted by the DAC 12 is output, as shown in FIG. 2, components called image components (folding components) other than the intermediate frequency component (signal band component: 20.1875 MHz) are included. Included in analog signal. In FIG. 2, the horizontal axis indicates the frequency domain (f / fs), and the vertical axis indicates the signal gain (Gain). Here, f is a normal frequency and fs is a sampling frequency.

  As shown in FIG. 2, each of the plurality of image components is a different frequency component. Since the waveform of the analog signal output from the DAC 12 is a rectangular wave, the analog signal is output by an impulse response (hereinafter referred to as a Sinc function response) of a Sinc function (Sinc (f / fs)). . Therefore, conventionally, components other than the components of the signal band are removed as unnecessary components, and a signal having a frequency to be used in wireless communication by performing processing (amplification processing or the like) only on necessary frequency components ( (RF signal: RadioFrequency) is generated and transmitted. However, in the present embodiment, a frequency component to be used in wireless communication is acquired using the image component that is an unnecessary component, and a signal of the acquired frequency component, that is, an RF signal is output.

Here, the relationship between the analog signal converted by the DAC 12 and the image component will be described.
The image component is generated by multiplication (mixing) of the sampling frequency used in the DAC 12 and the input signal. For example, if the input signal is a signal generated by the frequency converter 11, that is, an IF signal orthogonally transformed in the digital domain, the image component is a harmonic of m times the sampling frequency (m is an integer of 1 or more). Is generated by multiplication with At this time, due to the Sinc function response, the second m image component and the second m−1 image component are in a phase opposite relationship to each other. When the value of m is an odd number, the second m−1 and the input signal (that is, the converted analog signal) have the same phase. When the value of m is an even number, the second m and the input signal (that is, the converted analog signal) have the same phase. That is, each of the image components shown by the broken line in the image components shown in FIG. 2 and the IF signal are in a phase opposite to each other. Other image components and the IF signal have the same phase relationship. For example, the phase of the 17th (= 2 × 9-1) image component is the same as that of the input signal because the value of m is an odd number (9).

(4) BPF13
The BPF 13 filters only a required frequency component among a plurality of frequency components in the analog signal output from the DAC 12.
Hereinafter, this will be specifically described with reference to FIG.
In a specific power-saving radio standard ARIB (Association of Radio Industries and Businesses) -T67, a high frequency band from 429.8125 MHz to 429.9125 MHz is allocated as a usable band for wireless communication.

As shown in FIG. 2, when the sampling frequency is set to 50 MHz, the 9 times sampling frequency (450 MHz) is a frequency close to the above frequency band. Then, the BPF 13 can obtain a signal having a frequency permitted for wireless communication by filtering the seventeenth image component among the plurality of image components shown in FIG.
Usually, the frequency of each image component differs depending on the intermediate frequency. Therefore, it is necessary to determine the intermediate frequency so that the frequency of the seventeenth image component becomes a frequency permitted for wireless communication. For example, if the frequency to be used for transmission in the high frequency band from 429.8125 MHz to 429.9125 MHz, that is, the frequency of the 17th image component is 429.8125 MHz, the intermediate frequency is 9 times the sampling frequency (450 MHz). This is the difference from the 17th image component. This is because a signal in the transmission band (here, an intermediate frequency signal) and a plurality of image signals are symmetric with respect to a position (in this case, an integer multiple of the sample frequency) that becomes NULL due to a Sinc function response. This is because it exists in a position.

  Accordingly, the frequency conversion unit 11 converts the frequency of the modulation signal so that the intermediate frequency is 20.15875 MHz (= 450 MHz−429.8125 MHz). ) To selectively transmit the 429.8125 MHz image component belonging to), a signal having a frequency permitted for wireless communication can be obtained.

(5) Signal amplifier 14
As shown in FIG. 1, the signal amplifying unit 14 includes a driver amplifier (DRV) 23 and a power amplifier (PA) 24. Using these amplifiers, an analog signal having an image component obtained by the BPF 13 can be obtained. The transmission level is amplified to a predetermined level.
Here, it demonstrates using a specific example.

FIG. 3 shows the result of amplification of the signal level and noise level input to the DAC 12 by the signal amplifying unit 14.
In the example illustrated in FIG. 3, the signal level input to the DAC 12 is 4 dBm. This signal is converted into an analog signal by the DAC 12, and the level of the seventeenth image component at the time of output is −29 dBm, which is 33 dB lower than the level of the input signal due to the Sinc function response. Further, a quantization noise level, which is a kind of noise level generated when converting to an analog signal, can be input since the SN (signal-noise ratio) of about 50 dB can be theoretically realized if the bit resolution of the DAC 12 is 8 bits. 50 dBm lower than the signal level. Since the input signal level is 4 dBm, it is -46 dBm here. This quantization noise level is also reduced by 33 dB due to the Sinc function response. That is, the level of quantization noise output from the DAC 12 is 79 dBm. The thermal noise level, which is another noise level, is -134 dBm. This is 55 dB lower than the level of the 17th image component, and is negligible, not related to the SN of the signal.

  As a result, the signal level of the analog signal input to the signal amplifying unit 14 (the signal level of the seventeenth image component) is −29 dBm. According to the standard, the level of the transmission output is up to 10 dBm, so the gain obtained by the signal amplifying unit 14 is 39 dB. Therefore, by setting the gain at DRV 23 to 29 dB and the gain at PA 24 to 10, the level of the transmitted signal becomes 10 dB. At this time, the quantization noise level (−79 dBm) of the quantization noise output from the DAC 12 is also amplified by the signal amplifying unit 14, and the level after amplification becomes −40 dB. According to the standard, the leakage power in the band of ± 2.55 kHz with 12.5 kHz detuning is 40 dB or less, and when the transmission output level is 10 dBm, the leakage power must be suppressed to -30 dBm or less. The level -40 dBm after amplification of the quantization noise satisfies this rule.

(6) LPF15
The LPF 15 removes noise included in the signal output from the signal amplifying unit 14.
The signal from which the noise has been removed is transmitted to the outside via the antenna 16.
1.2 Operation Here, the operation of the radio circuit 1 will be described with reference to the flowchart shown in FIG.

The radio circuit 1 modulates a signal of data to be transmitted by the modulator 10 to generate an I signal and a Q signal (step S5).
The radio circuit 1 converts the frequency of the modulated signal (I signal, Q signal) generated by the modulator 10 into an intermediate frequency by the frequency converter 11 (step S10).
The radio circuit 1 converts the modulation signal of the intermediate frequency into an analog signal by the DAC 12 (Step S15).

The radio circuit 1 uses the BPF 13 to filter a specific image component (here, the seventeenth image component) among a plurality of image components having different frequencies generated when the DAC 12 boosts the analog signal (step S20). .
The radio circuit 1 amplifies the signal level of the filtered image component by the signal amplifying unit 14 so as to be an allowed signal level (step S25).

The radio circuit 1 removes noise from the amplified signal by the LPF 15 and transmits a signal via the antenna 16 (step S30).
2. Modifications In the above-described embodiment, the method of implementing the present invention has been described, but it is needless to say that the embodiment of the present invention is not limited thereto. Hereinafter, various modified examples included in the present invention other than the above-described embodiment will be described.

2.1 First Modification The Sinc function response in the DAC 12 includes regions (second, third, sixth, and seventh image components) whose phases are inverted as shown in FIG.
For example, when a signal is transmitted using the seventh image component, the phase of the signal that should be originally used for transmission and the phase of the seventh image component have an opposite phase relationship. Therefore, when a 101010 signal is transmitted on the transmitting side, the receiving side expects signals to be received in the order of 101010. Therefore, the start point for one symbol is erroneously synchronized as shown in FIG. .

(1) Configuration In order to prevent the erroneous synchronization described above, as shown in FIG. 7, in the radio circuit 1a of the present modification, in addition to the components of the radio circuit 1 of the above embodiment, the phase inverting unit 30 By preparing, the above problems are solved.
The phase inverter 30 is provided between the frequency converter 11 and the DAC 12 and inverts the phase of the signal output from the frequency converter 11.

As a result, the phase of the seventh image component output from the DAC 12 is in an opposite phase relationship to the phase when the phase inverting unit 30 is not used, so that the start point for one symbol is erroneously synchronized on the receiving side. Never do.
(2) Operation The operation of the radio circuit 1a can be realized by adding the following step S11 between step S10 and step S15 in the flowchart shown in FIG.

Step S11 is a step in which the phase inverting unit 30 inverts the phase of the intermediate frequency modulation signal generated in Step S10.
2.2 Second Modification Usually, amplitude distortion due to a Sinc function response occurs in an image component. Amplitude distortion has the effect of increasing the error rate in a wideband signal.

In the above embodiment, since image components are used, it is necessary to correct the image components to be used in order to reduce the influence of amplitude distortion.
(1) Configuration In order to perform the above correction, as shown in FIG. 8, in the radio circuit 1b of this modification, in addition to the components of the radio circuit 1 shown in the above embodiment, the frequency converter 11 and the DAC 12 A correction filter 40 is provided between the two.

  The correction filter 40 flattens the amplitude distortion in the image component to be used. Specifically, the correction filter 40 convolves a signal with a πx / sin (πx) characteristic (complement coefficient). In the DAC 12, the value of the Sinc function at a frequency corresponding to the second image component is represented by sin (πx) / πx. Therefore, convolution of this value with the πx / sin (πx) characteristic, that is, a value indicating that the characteristic is flat by multiplying this value by the πx / sin (πx) characteristic in the frequency domain (f / fs). “1” can be obtained.

In FIG. 9, the correction for the second image component is shown. Here, the intermediate frequency is 10 MHz and the sampling frequency (fs) is 50 MHz. Then, the frequency of the second image component is 60 (50 + 10), and the value of f / fs at this time is 1.2. In this example, signals are communicated in a band of f / fs = 1.2 ± 0.01.
When the value of f / fs is 1.19, the value of the Sinc function is about −0.151, and the complementary coefficient at this time is −6.65. Therefore, when these values are multiplied, the result is approximately 1. When the value of f / fs is 1.2, the value of the Sinc function is about −0.1558, and the complementary coefficient at this time is −6.4. Also in this case, the value after multiplication is approximately 1.

Therefore, it can be seen that in the corrected second image component, the amplitude distortion is eliminated by multiplying the complementary coefficient.
(2) Operation The operation of the radio circuit 1b can be realized by adding step S12 shown below between step S10 and step S15 in the flowchart shown in FIG.

Step S12 is a step in which the correction filter 40 flattens the amplitude distortion with respect to the image component to be used in the intermediate frequency modulation signal generated in step S10.
2.3 Other Modified Examples In addition to the above modified examples, the present invention includes the following modified examples.
(1) In the above-described embodiment and the first modification, the image component to be used is fixed as either a component having the same phase as the intermediate frequency signal or a component having the opposite phase, but is not limited thereto.

Each time transmission processing is performed, an image component to be used may be selected.
In this case, in addition to the components of the radio circuit 1a shown in FIG. 7, a switching unit for switching as follows is provided. The switching unit connects the frequency conversion unit 11 and the DAC 12 when an image component in phase with the intermediate frequency signal is selected, and the frequency conversion unit 11 and the DAC 12 when an image component having an opposite phase is selected. Switch to connect to.

(2) The present invention may be a combination of the above embodiment and each of the above modifications.
3. Second Embodiment In the first embodiment and each of the modifications described above, the radio circuit that performs signal transmission has been described. Here, a transceiver that performs transmission and reception will be described.

3.1 Configuration As shown in FIG. 10, the transceiver 100 of the present embodiment includes the radio circuit 1 shown in the first embodiment and a sampling receiver that receives a signal generated without using a synthesizer. 2 and a switch 3.
Since the wireless circuit 1 has already been described in the first embodiment, a description thereof will be omitted.

The antenna 16 transmits and receives signals. The switch 3 performs switching so that the antenna 16 and the radio circuit 1 are connected when a signal is transmitted, and the antenna 16 and the sampling receiver 2 are connected when a signal is received.
The sampling receiver 2 includes a demodulation unit 110, an orthogonal transformation unit 111, BPFs 112 and 114, an analog-to-digital conversion circuit (ADC) 113, a variable gain amplifier (PGA) 115, a low noise amplifier (PGA). LNA: Low Noise Amplifier (116) and LPF 117. In this case, a synthesizer is not necessary.

The LPF 117 removes noise included in the signal received from the antenna 16.
The LNA 116 amplifies the received signal and generates little low noise.
The PGA 115 operates in conjunction with an automatic gain control (AGC) algorithm so that the amplitude level of a signal input to the ADC 113 described later is constant.

The BPF 114 filters only a signal having a frequency to be demodulated so that the ADC 113 is not saturated with an unnecessary signal other than the signal to be demodulated.
The ADC 113 is a circuit that converts a received analog signal into a digital signal. When a digital signal is output from the ADC 113, a plurality of image components having different frequencies are output in the same manner as when the DAC 12 of the wireless circuit 1 is output.

The BPF 112 filters an image component corresponding to the component of the IF signal generated on the transmission side.
The orthogonal transform unit 111 decomposes the filtered image component signal into an I component and a Q component. Then, the orthogonal transform unit 111 uses the ROM table 22 for the decomposed I component and Q component to generate a waveform-shaped I signal and Q signal.

The demodulator 110 demodulates the I signal and the Q signal to obtain original data transmitted on the transmission side.
With this configuration, the transceiver 100 can transmit and receive signals without using a synthesizer.
In the present embodiment, the transceiver 100 includes the wireless circuit 1, but the present invention is not limited to this. The transceiver 100 may include any one of the radio circuit 1b shown in the first modification, the radio circuit 1b shown in the second modification, and the radio circuit shown in the other modification (1). Good. No matter which radio circuit is used, the configuration of the sampling receiver 2 is not changed.

3.2 Application Example Here, an application example of the transceiver 100 will be described with reference to FIG.
FIG. 11 shows an illumination control system 1000 using the transceiver 100.
The illumination control system 1000 includes an illumination control switch 1001, fluorescent lamp fixtures 1002, 1003, 1004, 1005, and a power line 1006.

The illumination control switch 1001 includes a transceiver 100a and switches 1010, 1011, 1012, and 1013.
The transmitter / receiver 100a has the same configuration as the above-described transmitter / receiver 100, and supplies a fluorescent light fixture 1002 to 1005 with a power ON / OFF signal and a dimming signal indicating the intensity of light according to a user instruction. Send. Further, the transceiver 100a receives signals transmitted from the fluorescent lamp fixtures 1002 to 1005, respectively. The signal transmitted from the fluorescent lamp fixture is, for example, a signal indicating that the signal transmitted from the illumination control switch 1001 has been normally received.

  Each of the switches 1010 to 1013 does not need to correspond one-to-one with the fluorescent lamp fixtures 1002 to 1005. 1003 and 1003 are ON / OFF, the switch 1012 is only ON / OFF for the fluorescent lamps 1004 and 1005, and the switch 1013 is a switch for controlling functions such as dimming control optimal for the fluorescent lamps 1002 to 1005 for presentation.

Since each of the fluorescent lamp fixtures 1002 to 1005 has the same constituent elements, the fluorescent lamp fixture 1002 will be described here.
The fluorescent lamp apparatus 1002 includes a transceiver 100b in addition to the fluorescent lamp.
The transceiver 100b has the same configuration as that of the transceiver 100 described above, and receives a signal transmitted from the illumination control switch 1001. Further, the transceiver 100b transmits a signal indicating that the signal transmitted from the illumination control switch 1001 has been normally received.

The power line 1006 is used to supply power to the fluorescent lamp fixtures 1002 to 1005 and to transmit a signal instructed by operating at least one of the switches 1010 to 1013.
As described above, in the illumination control system 1000, the ON / OFF signal and the dimming signal are instructed from the illumination control switch 1001 to the fluorescent lamp fixtures 1002 to 1005 by wireless communication, and the fluorescent lamp fixtures 1002 to 1005 are controlled. be able to.

When the power itself is cut off (OFF instruction) or the output control (dimming) is controlled by a switch from 1010 to 1013, only the fluorescent lamp apparatus connected to the power line for controlling the cutting or output can be controlled.
Therefore, as in the lighting control system 1000, the instruction is performed by wireless communication, so that the supply of power from the power line 1006 is not changed, and the fluorescent lamp fixtures 1002 to 1005 are on the device side that receives the signal wirelessly. Electric power can be choked, and fine control is possible for each of the fluorescent lamp fixtures 1002 to 1005.

The radio circuits in the first and second embodiments, the modifications, and the present embodiment do not use a synthesizer to generate a signal to be transmitted. For this reason, it is not necessary to secure a region for mounting a synthesizer as in the conventional case, so that the size of the radio circuit can be reduced.
Moreover, a microcomputer for inverter control is mounted on a lighting device such as a conventional fluorescent lamp fixture. Therefore, by downsizing the radio circuit of the transceiver, it can be integrated in the microcomputer, and illumination control by radio communication becomes possible.

4). Summary As described above, the radio circuit shown in each embodiment and each modification does not use a synthesizer, so that the layout area of the synthesizer shown in FIG. 13 is not required, and the miniaturization can be realized.
5. Supplement (1) A radio circuit according to one aspect of the present invention includes a signal generation unit that generates a modulation signal from a signal indicating data to be transmitted, and a frequency conversion unit that converts the frequency of the modulation signal into an intermediate frequency. A signal conversion unit that converts the modulated signal converted to the intermediate frequency into an analog signal, and the intermediate signal above and below a frequency that is an integer multiple of a sampling frequency of the signal conversion unit during the conversion by the signal conversion unit. A filter that filters image components belonging to a specific high frequency band among image components that appear apart by a frequency, a signal amplification unit that amplifies the image components filtered by the filter, and amplification by the signal amplification unit And a transmission unit for transmitting the image component.

According to this configuration, since the radio circuit generates a signal to be transmitted using an image component belonging to a specific high frequency band, a synthesizer is not necessary. Therefore, the wireless circuit can be reduced in size.
(2) Here, the frequency of the image component belonging to the specific frequency band is a first frequency, and the intermediate frequency is an integral multiple of the first frequency and the sampling frequency and is closest to the first frequency. It may be a difference value from the second frequency.

According to this configuration, the radio circuit can specify the intermediate frequency by setting the frequency of the image component to be filtered as the first frequency in the frequency band to be used for transmission. As a result, when the frequency to be used for transmission is determined in advance, the intermediate frequency can be determined at the manufacturing stage of the radio circuit, so that an easy design is possible.
(3) Here, the image component belonging to the specific frequency band is in a phase opposite to the phase of the modulation signal converted to the intermediate frequency, and the radio circuit further includes the signal conversion unit Prior to conversion, a phase inversion unit that inverts the phase of the modulated signal converted to the intermediate frequency may be provided.

According to this configuration, when the phase of the image component to be filtered is opposite to the phase of the modulation signal, the radio circuit inverts the phase of the modulation signal so that the specific image component at the time of signal transmission is transmitted. Is in phase with the phase of the modulation signal before inversion. Therefore, the receiving side can synchronize at the correct timing.
(4) Here, the wireless circuit further complements the image component so that amplitude distortion of the image component belonging to the one frequency band becomes flat prior to the conversion by the signal conversion unit. It is good also as providing the complement part which performs.

According to this configuration, since the radio circuit can correct the amplitude distortion, a signal without distortion can be transmitted during transmission.
(5) Here, the wireless circuit may be provided in a wireless transceiver that performs wireless communication.
According to this configuration, the wireless circuit can be miniaturized by using the wireless circuit for the transceiver.

  (6) Moreover, the illumination control system which consists of 1 or more lighting fixtures which are 1 aspect of this invention, and the control apparatus which controls the said 1 or more lighting fixtures by radio | wireless, The said control apparatus controls lighting fixtures. A signal generation unit that generates a modulation signal from the control signal according to the above, a frequency conversion unit that converts the frequency of the modulation signal into an intermediate frequency, and a signal converter that converts the modulation signal converted into the intermediate frequency into an analog signal And image components appearing above and below the frequency at every integer multiple of the sampling frequency of the signal conversion unit at the time of the conversion by the signal conversion unit and belonging to a specific high frequency band A filter for filtering an image component, a signal amplification unit for amplifying the image component filtered by the filter, and the image component amplified by the signal amplification unit Each of the one or more lighting fixtures receives the image component, demodulates the received image component to generate the control signal, and based on the generated control signal, the lighting unit It is characterized by controlling.

  According to this configuration, the radio circuit of the illumination control system generates a signal to be transmitted using an image component belonging to a specific high frequency band, so that a synthesizer is not necessary. Therefore, it is possible to reduce the size of the radio circuit, and it is also possible to incorporate the miniaturized radio circuit into a circuit provided in the lighting fixture.

DESCRIPTION OF SYMBOLS 1, 1a, 1b Radio circuit 2 Sampling receiver 3 Switch 10 Modulator 11 Frequency conversion part 12 Digital-analog conversion circuit (DAC)
13, 112, 114 Band pass filter (BPF)
14 Signal Amplifier 15, 117 Low Pass Filter (LPF)
16 Antenna 21 Orthogonal Transformer 22 ROM Table 23 Driver Amplifier (DRV)
24 Power Amplifier (PA)
DESCRIPTION OF SYMBOLS 30 Phase inversion part 40 Correction filter 100, 100a-100e Transceiver 110 Demodulation part 111 Orthogonal transformation part 113 Analog / digital conversion circuit (ADC)
115 Variable Gain Amplifier (PGA)
116 Low noise amplifier (LNA)
1000 Lighting control system 1001 Lighting control switch 1002 Fluorescent lamp fixture 1006 Power line 1010 to 1013 switch

Claims (5)

A signal generator that generates a modulated signal from a signal indicating data to be transmitted;
A frequency converter that converts the frequency of the modulated signal to an intermediate frequency;
A signal converter that converts the modulated signal converted to the intermediate frequency into an analog signal;
Filtering out image components belonging to a specific frequency band from among image components appearing above and below the frequency every integer multiple of the sampling frequency of the signal conversion unit during the conversion by the signal conversion unit. Filters,
A signal amplifying unit for amplifying the image component filtered by the filter;
A wireless circuit comprising: a transmission unit that transmits the image component amplified by the signal amplification unit ;
The image component belonging to the specific frequency band is in a phase relationship opposite to the phase of the modulation signal converted to the intermediate frequency,
The radio circuit further includes:
Prior to the conversion by the signal conversion unit , the wireless circuit includes a phase inversion unit for inverting the phase of the modulated signal converted to the intermediate frequency . The frequency of the image component belonging to the specific frequency band is a first frequency,
The intermediate frequency is
2. The radio circuit according to claim 1, wherein the wireless circuit is a difference value between the first frequency and a second frequency that is an integral multiple of the sampling frequency and is closest to the first frequency. The radio circuit further includes:
Prior to the conversion by the signal conversion unit, the image processing apparatus includes a complementing unit that complements the image component so that amplitude distortion of the image component belonging to the specific frequency band becomes flat. The radio circuit according to 2. The wireless circuit according to any one of claims 1 to 3 , wherein the wireless circuit is provided in a wireless transceiver that performs wireless communication. An illumination control system comprising one or more lighting fixtures and a control device that wirelessly controls the one or more lighting fixtures,
The controller is
A signal generator for generating a modulation signal from a control signal related to the control of the lighting fixture;
A frequency converter that converts the frequency of the modulated signal to an intermediate frequency;
A signal converter that converts the modulated signal converted to the intermediate frequency into an analog signal;
Filtering out image components belonging to a specific frequency band from among image components appearing above and below the frequency every integer multiple of the sampling frequency of the signal conversion unit during the conversion by the signal conversion unit. Filters,
A signal amplifying unit for amplifying the image component filtered by the filter;
A transmission unit for transmitting the image component amplified by the signal amplification unit,
Each of the one or more lighting fixtures is
Receiving the image component, demodulating the received image component to generate the control signal, based on the generated control signal, control the illumination,
The image component belonging to the specific frequency band is in a phase relationship opposite to the phase of the modulation signal converted to the intermediate frequency,
The control device further includes:
Prior to the conversion by the signal conversion unit , the illumination control system includes a phase inversion unit that inverts the phase of the modulation signal converted to the intermediate frequency .

Images