WO2012164697A1 - 無線送信機、無線受信機、無線通信システム、昇降機制御システムおよび変電設備制御システム - Google Patents
無線送信機、無線受信機、無線通信システム、昇降機制御システムおよび変電設備制御システム Download PDFInfo
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- WO2012164697A1 WO2012164697A1 PCT/JP2011/062576 JP2011062576W WO2012164697A1 WO 2012164697 A1 WO2012164697 A1 WO 2012164697A1 JP 2011062576 W JP2011062576 W JP 2011062576W WO 2012164697 A1 WO2012164697 A1 WO 2012164697A1
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- frequency
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- wireless
- carrier frequency
- wireless transmitter
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B66—HOISTING; LIFTING; HAULING
- B66B—ELEVATORS; ESCALATORS OR MOVING WALKWAYS
- B66B1/00—Control systems of elevators in general
- B66B1/34—Details, e.g. call counting devices, data transmission from car to control system, devices giving information to the control system
- B66B1/3415—Control system configuration and the data transmission or communication within the control system
- B66B1/3446—Data transmission or communication within the control system
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
- H04B1/02—Transmitters
- H04B1/04—Circuits
- H04B1/0475—Circuits with means for limiting noise, interference or distortion
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
- H04B1/02—Transmitters
- H04B1/04—Circuits
- H04B1/0483—Transmitters with multiple parallel paths
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
- H04B1/06—Receivers
- H04B1/10—Means associated with receiver for limiting or suppressing noise or interference
- H04B1/1081—Reduction of multipath noise
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04J—MULTIPLEX COMMUNICATION
- H04J11/00—Orthogonal multiplex systems, e.g. using WALSH codes
- H04J11/0023—Interference mitigation or co-ordination
- H04J11/0063—Interference mitigation or co-ordination of multipath interference, e.g. Rake receivers
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L27/00—Modulated-carrier systems
- H04L27/10—Frequency-modulated carrier systems, i.e. using frequency-shift keying
- H04L27/12—Modulator circuits; Transmitter circuits
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L27/00—Modulated-carrier systems
- H04L27/10—Frequency-modulated carrier systems, i.e. using frequency-shift keying
- H04L27/14—Demodulator circuits; Receiver circuits
Definitions
- the present invention relates to a long-life wireless transmitter, a wireless receiver, and a wireless communication system that realize highly reliable wireless communication.
- a wireless communication system that realize highly reliable wireless communication.
- the present invention relates to a machine, a radio receiver, a radio communication system, an elevator control system, and a substation control system.
- wireless communication technology has made remarkable progress in the broadcasting field and communication field, and has overcome problems related to reliability such as the disconnection unique to wireless communication.
- wireless communication technology is increasingly applied to the control field and the measurement field, which require higher reliability than the broadcasting field and the communication field.
- social infrastructure equipment equipment that constructs social infrastructure
- the social infrastructure equipment is, for example, an elevator system shown in FIG. 12, a substation monitoring system shown in FIG.
- Social infrastructure equipment is overwhelmingly large in size compared to general consumer equipment and is made of metal members. This social infrastructure device itself becomes an electromagnetic wave scattering source. Therefore, wireless communication in social infrastructure equipment is often performed in an environment where multiple waves (multipath) generated by scattering interfere with each other. For this reason, it is desired to realize highly reliable wireless communication in an environment where interference due to multiple waves (multipath) occurs.
- reflection is caused by the distribution of fixtures that are electromagnetic wave scatterers.
- the average distance of this radio wave reflection is approximately the same as the antenna distance (half-wave distance of the electromagnetic wave) for realizing space diversity, the energy of the electromagnetic wave reaching the antenna due to interference due to another multiple reflection is zero. The possibility of becoming greater. Therefore, it becomes difficult to ensure the reliability of wireless communication.
- the electromagnetic wave generated by the wireless transmitter is reflected by the social infrastructure equipment itself to become a multipath wave, and may arrive at the receiver from all directions. Therefore, when the space diversity technique is applied, many antennas are required. For example, it is necessary to prepare a plurality of arrayed antennas even if it is limited when multiple waves (multipath) come in the plane direction. Since the distance between adjacent antennas is a half wavelength of the received electromagnetic wave, there is a possibility that it exceeds the size that can be installed in this social infrastructure device.
- Patent Document 1 Japanese Patent Laid-Open No. 10-135919
- FIG. 3 disclose a technique for rotating the plane of polarization of radio waves in order to suppress the effects of fading and noise in wireless communication.
- paragraph 0006 of the specification of Patent Document 1 states, “On the transmitting side, two pairs of dipole antennas that are crossed at right angles and rotated at right angles to the transmission direction for rotating and transmitting the polarization plane of the radio wave, and this Comprising a transmitter having two sets of balanced modulated wave outputs for exciting the signal and comprising a receiver for detecting and receiving the rotation of the polarization plane of the incoming radio wave on the receiver side.
- Patent Document 2 Japanese Patent Laid-Open No. 61-024339 uses a carrier wave having two different first frequencies without using the third frequency, and different information using the second frequency respectively. And a method of transmitting these two carriers using different polarized waves and detecting a difference frequency from these two carriers in the receiver to obtain a third frequency.
- Patent Document 1 is effective in removing the effects of fading and noise that occur during transmission and reception of radio waves.
- the present invention describes nothing about realizing highly reliable wireless communication in an environment where interference due to multiple waves (multipath) occurs, and reducing the size of the transmitting antenna and the receiving antenna. Absent.
- Patent Document 2 does not require a pilot signal wave, and can be applied to an analog modulation method such as FM (Frequency Modulation).
- FM Frequency Modulation
- the configuration is simple and compensation for each signal wave for communication is easy.
- this invention does not describe anything about digital processing of information signals after detecting a predetermined frequency component in the receiver.
- the present invention provides a wireless transmitter, a wireless receiver, a wireless communication system, and an elevator control system capable of improving the reliability of digital wireless communication due to multiple wave interference in an environment where a plurality of electromagnetic wave scatterers are present. It is another object of the present invention to provide a substation equipment control system.
- the wireless transmitter of the present invention includes a first transmission wave having a first carrier frequency modulated by an information signal having a predetermined frequency band, and a second transmission wave modulated by the information signal.
- Other means will be described in the embodiment for carrying out the invention.
- a wireless transmitter, a wireless receiver, a wireless communication system, and an elevator control system capable of improving the reliability of digital wireless communication due to interference of multiple waves in an environment where a plurality of electromagnetic wave scatterers are present.
- a substation equipment control system can be provided.
- FIGS. 1A to 1D are diagrams showing the configuration of a wireless communication system in the first embodiment.
- FIG. 1A shows a wireless transmitter 10 of the present embodiment.
- FIG. 1B shows the wireless receiver 30 of the present embodiment.
- FIG.1 (c) has shown the power spectrum of the transmission signal of the wireless transmitter 10 of this embodiment.
- FIG. 1D shows the power spectrum of the output signal of the low pass filter 35.
- the wireless communication system according to this embodiment includes a wireless transmitter 10 and a wireless receiver 30.
- the radio transmitter 10 shown in FIG. 1A includes a transmission-side control unit 14, variable oscillators 12-1 and 12-2, modulators 13-1 and 13-2, an information generation circuit 11, and a baseband.
- a circuit 17 and transmission antennas 20-1 and 20-2 are provided.
- the output side of the transmission side control unit 14 is connected to the variable oscillators 12-1 and 12-2.
- the output side of the variable oscillator 12-1 is connected to the modulator 13-1.
- the output side of the variable oscillator 12-2 is connected to the modulator 13-2.
- the output side of the information generation circuit 11 is connected to the baseband circuit 17.
- the output side of the baseband circuit 17 is connected to the modulators 13-1 and 13-2, respectively.
- the output of the modulator 13-1 is connected to the transmission antenna 20-1.
- the output of the modulator 13-2 is connected to the transmission antenna 20-2.
- the information generation circuit 11 generates an information signal.
- the baseband circuit 17 converts the input information signal into an information signal having a frequency band f1 that is a predetermined frequency.
- the transmission side control unit 14 controls the signal frequency output from the variable oscillators 12-1 and 12-2.
- the variable oscillator 12-1 outputs a first carrier wave having a frequency (f0 + ⁇ f) obtained by adding a frequency difference ⁇ f corresponding to the output signal of the transmission side control unit 14 from the frequency f0.
- the variable oscillator 12-2 outputs a second carrier wave having a frequency (f0 ⁇ f) obtained by subtracting the frequency difference ⁇ f corresponding to the output signal of the transmission side control unit 14 from the frequency f0.
- the modulator 13-1 modulates the information signal based on the input oscillation signal that is the first carrier wave.
- the modulator 13-2 modulates the information signal based on the input oscillation signal that is the second carrier wave.
- the frequency difference ⁇ f is smaller than the frequency f0.
- the frequency f1 which is a predetermined frequency, is smaller than the frequency difference ⁇ f. That is, f0> ⁇ f> f1.
- FIG. 1B shows the wireless receiver 30 of the present embodiment.
- the radio receiver 30 illustrated in FIG. 1B includes a reception antenna 31, a mixer 32, an oscillator 33, a low-pass filter 35, an analog / digital converter 36, and a baseband circuit 51.
- the receiving antenna 31 receives radio waves transmitted from the transmitting antennas 20-1 and 20-2.
- the oscillator 33 outputs an oscillation signal having a frequency f0.
- the mixer 32 mixes two input signals and outputs them. Specifically, the oscillation signal having the frequency f0 and the signal received by the receiving antenna 31 are mixed. Thereby, product detection is performed.
- the low-pass filter 35 suppresses a spectral component exceeding a predetermined frequency in the input signal and transmits a low-frequency spectral component.
- the analog / digital converter 36 converts the input signal into a digital signal.
- the baseband circuit 51 converts the input digital signal into a baseband signal that is an original information signal.
- the output side of the receiving antenna 31 and the output side of the oscillator 33 are connected to the mixer 32.
- the output side of the mixer 32 is connected to an analog / digital converter 36 via a low-pass filter 35.
- the output side of the analog / digital converter 36 is connected to the baseband circuit 51.
- FIG. 1C shows a power spectrum of the wireless transmitter 10 of the present embodiment.
- the horizontal axis of the figure indicates the frequency.
- the vertical axis in the figure indicates the spectral density corresponding to the frequency.
- the frequency may be abbreviated as freq.
- the spectral density may be described as spectrum.
- the power spectrum shown in FIG. 1C relates to an electromagnetic wave radiated from the transmission antennas 20-1 and 20-2.
- the variable oscillator 12-1 outputs a signal having a frequency (f0 + ⁇ f) around the frequency f0.
- the variable oscillator 12-2 outputs a signal having a frequency (f0 ⁇ f) around the frequency f0.
- the frequency difference ⁇ b is the difference between the power spectrum peaks of the electromagnetic waves radiated from the transmitting antennas 20-1 and 20-2 when the frequency ⁇ f is the largest.
- the frequency difference ⁇ a is the difference between the power spectrum peaks of the electromagnetic waves radiated from the transmitting antennas 20-1 and 20-2 when the frequency ⁇ f is the smallest.
- FIG. 1D shows the power spectrum of the output signal of the low-pass filter 35 of the present embodiment.
- the horizontal axis of the figure indicates the frequency.
- the vertical axis in the figure indicates the spectral density corresponding to the frequency.
- the power spectrum of the signal output from the receiving antenna 31 to the mixer 32 is product-detected by the mixer 32 to a frequency corresponding to the peak frequency difference. Therefore, the power spectrum of the output signal of the low-pass filter 35 has a peak at the frequency ⁇ b / 2 to the frequency ⁇ a / 2.
- the information generation circuit 11 generates an information signal and outputs it to the baseband circuit 17.
- the baseband circuit 17 converts the input information signal into an information signal having a frequency band f1, which is a predetermined frequency, and outputs the information signal to the modulators 13-1 and 13-2.
- the modulator 13-1 modulates the information signal having the frequency band f1 with the oscillation signal output from the variable oscillator 12-1, and transmits it from the transmission antenna 20-1.
- the modulator 13-2 modulates the information signal having the frequency band f1 with the oscillation signal output from the variable oscillator 12-2, and transmits it from the transmission antenna 20-2.
- the electromagnetic waves radiated from the transmitting antennas 20-1 and 20-2 are reflected at different incident angles and different frequencies when passing through a space where many non-specific reflectors exist.
- the electromagnetic wave has a polarization, and the phase shift angle of this polarization changes depending on the polarization vector for different incident angles. For example, if the polarization vector is orthogonal to the incident surface, the phase shift angle is 180 °. If the polarization vector is included with respect to the incident surface, the phase shift angle is 0 °.
- the electromagnetic waves of different frequencies radiated from the transmitting antennas 20-1 and 20-2 are reflected various times by various reflectors and various incident angles at various incident angles.
- the phase of the plurality of reflected waves arriving at the reception point changes between 0 ° and 180 ° in the rotation period due to the rotation of the polarization vector. Therefore, when the rotation period is divided on the time axis and the power of the received wave at each point after the division is observed, the set of each point after the division is combined with the reflected wave in reverse phase at the reception point. And a time point where reflected waves are combined in phase at the reception point and reception power is strengthened. By extracting the time points where reflected waves are combined in the same phase at the receiving point and the received power is strengthened by digital signal processing technology etc., it is easy to secure a wireless communication path even in a radio wave environment where there are many reflectors It becomes.
- the linearly polarized waves transmitted by the transmission antennas 20-1 and 20-2 are received by the reception antenna 31.
- the received signal includes a signal having a frequency (f0 ⁇ ⁇ f).
- This received signal and the oscillation signal having the frequency f 0 output from the oscillator 33 are mixed by the mixer 32.
- product detection is performed, and a signal having a frequency ⁇ f corresponding to the frequency difference between the two is extracted.
- a signal (noise) having a predetermined frequency or higher is suppressed by the low-pass filter 35, and a signal spectrum of the frequency ⁇ f is extracted.
- the output signal of the low-pass filter 35 is converted into a digital signal via the analog / digital converter 36. This digital signal is converted into the original information signal by the baseband circuit 51.
- a radio wave emitted from the wireless transmitter 10 and subjected to multiple reflections by a plurality of reflectors and reaching the receiving antenna 31 is transmitted by the wireless receiver 30 into two transmission waves. Is converted into a signal having a frequency ⁇ f corresponding to the difference between the carrier frequency (f0 ⁇ ⁇ f) of the current and the frequency wind f0 output from the oscillator 33.
- the maximum value of the frequency difference between the carrier frequencies (f0 ⁇ ⁇ f) of the two transmission waves is the frequency ⁇ b, and the minimum value is the frequency ⁇ a.
- the first embodiment described above has the following effects (A) and (B).
- (A) The wireless transmitter 10 of this embodiment transmits two electromagnetic waves having different frequencies from the transmission antennas 20-1 and 20-2.
- the set of each point after the division is combined with the reflected wave in reverse phase at the reception point.
- a time point where reflected waves are combined in phase at the reception point and reception power is strengthened. Securing a wireless communication path even in a radio wave environment where there are many reflectors by extracting time points where reflected waves are combined in phase at this receiving point by digital signal processing technology and the received power is strengthened Becomes easy.
- the radio receiver 30 of the present embodiment converts the signal into a signal having a frequency ⁇ f corresponding to the difference between the carrier frequencies of the two transmission waves. This makes it possible to easily extract a time point at which the reflected wave is synthesized in phase at the reception point at a frequency ⁇ a / 2 to a frequency ⁇ b / 2 that is significantly lower than the carrier frequency f0 of the transmission wave. It is easy to secure a wireless communication path.
- FIGS. 2A to 2D are diagrams showing the configuration of the wireless communication system in the second embodiment. Elements identical to those of the wireless communication system of the first embodiment shown in FIGS. 1A to 1D are assigned the same reference numerals.
- the radio transmitter 10 shown in FIG. 2A has the same configuration as the radio transmitter 10 of the first embodiment shown in FIG.
- the radio receiver 30A shown in FIG. 2B has a variable bandpass filter 35A different from the lowpass filter 35 of the radio receiver 30 of the first embodiment shown in FIG. Other than having the part 34, it has the structure similar to the radio
- the output side of the reception side control unit 34 of this embodiment is connected to the variable bandpass filter 35A.
- the reception-side control unit 34 changes the pass frequency band of the variable bandpass filter 35A at the same time as the transmission wave frequency variable period used by the wireless transmitter 10.
- FIG. 2C shows a power spectrum of the wireless transmitter 10 of the present embodiment.
- the power spectrum of the wireless transmitter 10 of the present embodiment is the same as the power spectrum of the wireless transmitter 10 of the first embodiment shown in FIG.
- FIG. 2D shows the power spectrum of the output signal of the variable bandpass filter 35A of the present embodiment.
- the power spectrum of the output signal of the variable bandpass filter 35A of this embodiment is the same as the power spectrum of the output signal of the lowpass filter 35 of the first embodiment shown in FIG.
- FIGS. 3A to 3H are diagrams illustrating the operation of the wireless communication system in the second embodiment.
- FIG. 3A shows a predetermined sequence in which the wireless transmitter 10 repeats the training mode and the communication mode.
- FIG. 3B shows a predetermined sequence in which the wireless receiver 30A repeats the training mode and the communication mode.
- the horizontal axes in FIGS. 3A and 3B indicate a common time t.
- the wireless transmitter 10 When the wireless transmitter 10 starts communication, the wireless transmitter 10 operates in a training mode in which an optimal frequency is trained for a predetermined time, and then transitions to the communication mode to perform communication at an optimal frequency.
- the radio receiver 30A operates in a training mode in which an optimal frequency is trained for a predetermined time, and then transitions to a communication mode to perform communication at an optimal frequency.
- the optimum frequency is a frequency at which the interference of multiple waves is the smallest and therefore the component of the frequency f0 by the variable bandpass filter 35A is the highest.
- FIG. 3C shows a detailed sequence of the training mode of the wireless transmitter 10.
- FIG. 3D shows a detailed sequence of the training mode of the radio receiver 30A.
- the horizontal axes of FIGS. 3C and 3D indicate a common time t.
- the transmission-side control unit 14 of the wireless transmitter 10 is a variable oscillator at frequencies (f0 ⁇ ⁇ f1), (f0 ⁇ ⁇ f2), (f0 ⁇ ⁇ f3), and (f0 ⁇ ⁇ f4) every time T in the training mode. 12-1 and 12-2 are switched so as to oscillate.
- the radio receiver 30A switches so that the variable bandpass filter 35A performs a filter operation that passes signals of frequencies ⁇ f1, ⁇ f2, ⁇ f3, and ⁇ f4 every time 4T. That is, the reception frequency of the radio receiver 30A is switched.
- training is performed so that the combination of the oscillation frequency of the wireless transmitter 10 and the reception frequency of the wireless receiver 30A is optimized.
- FIG. 3E shows a detailed sequence of the communication mode of the wireless transmitter 10.
- FIG. 3F shows a detailed sequence of the communication mode of the radio receiver 30A.
- the horizontal axes in FIGS. 3E and 3F indicate the common time t.
- the wireless transmitter 10 and the wireless receiver 30A transmit and receive information with the optimal oscillation frequency ⁇ fi and the optimal reception frequency ⁇ fi.
- the vertical axis in FIG. 3G shows the power spectrum of the transmission signal of the wireless transmitter 10.
- the vertical axis in FIG. 3H indicates the power spectrum of the output signal of the variable bandpass filter 35A of the radio receiver 30A.
- the horizontal axes of FIGS. 3 (g) and 3 (h) indicate the frequency.
- FIG. 3G shows that the wireless transmitter 10 outputs a transmission signal having a peak at the frequency (f0 + ⁇ fi) and a transmission signal having a peak at the frequency (f0 ⁇ fi).
- FIG. 3H shows that the variable bandpass filter 35A of the radio receiver 30A outputs a signal having a peak at a frequency ⁇ fi that is a difference between the peaks of two transmission signals by product detection and bandpass filter processing. Show.
- FIG. 4 is a diagram illustrating a channel example (part 1) of the wireless communication system according to the second embodiment.
- the horizontal axis indicates the frequency, and the rectangle indicates each wireless communication channel Ch-1 to Ch-n (n is a natural number).
- the light gray portion indicates a combination of the carrier frequency (f0 ⁇ f1) of the first transmission wave and the carrier frequency (f0 + ⁇ f1) of the second transmission wave.
- the frequency f0 indicates the average frequency of the combination of the carrier frequency (f0 ⁇ f1) of the first transmission wave and the carrier frequency (f0 + ⁇ f1) of the second transmission wave.
- the dark gray portion indicates a combination of the carrier frequency (f0 ⁇ f2) of the first transmission wave and the carrier frequency (f0 + ⁇ f2) of the second transmission wave.
- the frequency f0 indicates the average frequency of the combination of the carrier frequency (f0 ⁇ f2) of the first transmission wave and the carrier frequency (f0 + ⁇ f2) of the second transmission wave.
- the radio communication system of the present embodiment divides the frequency band to be used into radio communication channels Ch-1 to Ch-n that are a plurality of narrow frequency bands.
- signal modulation is performed in the same manner as in the first embodiment.
- One center frequency (average frequency) f0 is set inside the frequency band to be used, two channels having the same frequency interval are selected on the left and right on the frequency axis of this frequency f0, and modulation is performed by the same signal. Then, it is emitted into the air by the transmitting antennas 20-1 and 20-2.
- the present embodiment can be applied to an existing wireless communication system that performs frequency division multiplexing in accordance with the Radio Law.
- FIG. 5 is a diagram illustrating a channel example (part 2) of the wireless communication system according to the second embodiment.
- the difference from FIG. 4 is that different center frequencies f0a and f0b are set in the frequency band.
- the wireless communication system in the present embodiment further uses a communication channel having a frequency (f0a + ⁇ f1) and a communication channel having a frequency (f0a ⁇ f1) that are located at equal intervals on the frequency axis from the center frequency f0a.
- a communication channel having a frequency (f0b + ⁇ f1) and a communication channel having a frequency (f0b ⁇ f1) located at equal intervals on the frequency axis from the center frequency f0b are used.
- a plurality of wireless channels can be realized simultaneously by selecting two communication channels located at equal intervals on the frequency axis from a plurality of center frequencies f0a and f0b without using the same channel at the same time. It is possible to increase the information communication capacity and improve the reliability of the wireless communication line.
- the second embodiment described above has the following effects (C) and (D).
- C The radio communication system of the present embodiment can be applied to an existing radio communication system that performs frequency division multiplexing in accordance with the Radio Law.
- D By simultaneously selecting two communication channels located at equal intervals on the frequency axis from a plurality of center frequencies f0a and f0b without simultaneously using the same channel, a plurality of wireless lines can be realized simultaneously. Thus, there is an effect in increasing the information communication capacity and improving the reliability of the wireless communication line.
- FIGS. 6A and 6B are diagrams illustrating the configuration of the wireless receiver according to the third embodiment. The same components as those of the wireless receiver 30 of the first embodiment shown in FIG.
- the wireless receiver 30B of this embodiment shown in FIG. 6A is connected to the baseband circuit 51 from the receiving antenna 31 via the delta-sigma modulator 40.
- the configuration is the same as that of the wireless receiver 30 of the first embodiment.
- the delta-sigma modulator 40 provided in the wireless receiver 30B of this embodiment includes resonators 42-1 and 42-2, an analog / digital converter 43, a digital / analog converter 45, an oscillator 44, And a reverse phase synthesizer 41-1.
- the resonator 42-1 which is the first resonator resonates at a resonance frequency corresponding to the carrier frequency (f0 ⁇ f) of the transmission wave.
- the resonator 42-2 as the second resonator resonates at a resonance frequency corresponding to the carrier frequency (f0 + ⁇ f) of the transmission wave.
- the analog / digital converter 43 compares, for example, a predetermined threshold value with an input signal and converts it to 1-bit digital.
- the oscillator 44 outputs an oscillation signal having a frequency fs.
- the digital / analog converter 45 converts, for example, a predetermined analog value according to a 1-bit digital signal.
- FIG. 6B is a diagram showing a power spectrum of the delta-sigma modulator 40 of the wireless receiver 30B of the present embodiment.
- the horizontal axis indicates the frequency, and the vertical axis indicates the spectrum density of the output signal of the delta-sigma modulator 40.
- the power spectrum of the output signal of the bandpass type delta sigma modulator 40 becomes 0 every integer multiple of the sampling frequency fs due to the alias signal specific to the digital signal.
- there is a zeroth-order harmonic peak In the frequency region below the sampling frequency fs, there is a zeroth-order harmonic peak.
- a peak of the first harmonic exists in the frequency region of the sampling frequency fs to 2fs.
- the peak of the nth harmonic exists in the frequency region of the sampling frequency (n ⁇ fs) to ((n + 1) ⁇ fs) (n is a natural number).
- the operation of the wireless receiver 30B will be described based on FIG.
- the digital / analog converter 45 outputs a feedback signal to the antiphase synthesizer 41-1.
- the feedback signal is subtracted from the reception signal output from the reception antenna 31 by the antiphase synthesizer 41-1.
- the output signal of the negative phase synthesizer 41-1 resonates at the respective resonance frequencies via the resonators 42-1 and 42-2 connected in parallel. Thereby, noise due to a frequency higher than the frequency f0 can be removed.
- the output signals of the resonators 42-1 and 42-2 are input to the analog / digital converter 43 and converted into digital signals.
- the digital signal is output to the baseband circuit 51 and also to the digital / analog converter 45, and is converted into the feedback signal described above.
- the analog / digital converter 43 and the digital / analog converter 45 are sampled by the common oscillator 44 at the same sampling frequency fs.
- the sampling frequency fs is an integer multiple of the carrier frequency (f0 ⁇ f) of the two transmission waves described above and the average frequency f0 of the carrier frequency (f0 + ⁇ f), and satisfies the following Expression 1.
- f0 M ⁇ fs (Formula 1).
- the delta sigma modulator 40 outputs a digital signal in which the time density of the bit “1” is increased according to the differential value (change amount) of the input signal.
- the carrier frequency (f0 ⁇ f) is obtained from the delta-sigma modulator 40.
- the output component of the transmitted wave signal and the transmitted wave signal having the carrier frequency (f0 + ⁇ f) is output as a digital signal.
- the third embodiment described above has the following effect (E).
- E According to the delta-sigma modulator 40 of the present embodiment, a modulated signal wave whose center frequency is a frequency sufficiently lower than the transmission wave is digitally used without using the mixer 32 and the oscillator 33 which are analog nonlinear circuits. It can be taken out as a signal. As a result, it is possible to easily extract the time point at which the reflected wave is synthesized in phase at the reception point by the digital signal processing performed by the baseband circuit 51 at the subsequent stage, and the radio receiver 30B can be simplified and highly reliable. Can be realized.
- FIGS. 7A and 7B are diagrams illustrating the configuration of a wireless receiver according to the fourth embodiment. The same elements as those of the wireless receiver according to the third embodiment shown in FIG.
- the wireless receiver 30C according to the present embodiment has a delta-sigma modulator 40C different from the delta-sigma modulator 40 included in the wireless receiver 30B according to the third embodiment.
- the wireless receiver 30B has the same configuration.
- the delta sigma modulator 40C of this embodiment further includes a digital signal interpolator 46 in addition to the delta sigma modulator 40 of the third embodiment, and the oscillator 44C includes a digital / analog converter 45,
- the configuration is the same as that of the delta-sigma modulator 40B of the third embodiment except that an oscillation signal having a sampling frequency (M ⁇ fs) is output.
- the digital signal interpolator 46 receives a 1-bit signal having a predetermined cycle and outputs a signal at a designated sampling cycle. For example, the digital signal interpolator 46 outputs the input digital signal as it is at the timing that coincides with the predetermined cycle, and interpolates and outputs “0” at the timing that does not coincide with the predetermined cycle.
- the delta-sigma modulator 40C of this embodiment inputs the output signal of the analog / digital converter 43 to the digital / analog converter 45 via the digital signal interpolator 46.
- FIG. 7B is a diagram illustrating the operation of the wireless receiver 30C of the present embodiment.
- the horizontal axis indicates the frequency, and the vertical axis indicates the power spectrum.
- the solid line indicates the power spectrum of the output signal of the delta-sigma modulator 40C, and for comparison, the power spectrum of the output signal of the delta-sigma modulator 40 shown in FIG. .
- the power spectrum of the output signal of the delta sigma modulator 40C becomes 0 for every integer multiple of the sampling frequency (M ⁇ fs) of the digital / analog converter 45 due to the alias signal specific to the digital signal. In the frequency region below the sampling frequency (M ⁇ fs), there is a peak of the 0th harmonic.
- the radio receiver 30C of the fourth embodiment shown in FIG. 7 is different from the radio receiver 30B of the third embodiment shown in FIG. 6 in that the digital-analog converter 45 used by the delta-sigma modulator 40C is different.
- the sampling frequency fs is an integral multiple of the sampling frequency (M ⁇ fs) of the analog / digital converter 43, and when the digital output of the analog / digital converter 43 is returned to the feedback loop, the digital signal interpolator 46 performs digital processing.
- the frequency of the signal is an integral multiple.
- the digital / analog converter 45 exhibits a low-pass attenuation characteristic of the SINC function due to the zero-order hold effect. As the difference between the average frequency of the carrier frequencies of the two transmission waves and the sampling frequency of the clock generation circuit increases, the gain of the hood back loop with respect to the transmission frequency decreases.
- the signal of the transmission wave having the frequency ⁇ f is output from the delta-sigma modulator 40C.
- the output component of the transmission wave signal having the carrier frequency (f0 ⁇ f) and the transmission wave signal having the carrier frequency (f0 + ⁇ f) are output as digital signals.
- the signal of frequency ⁇ f has the highest spectral density due to the zero-order hold effect. Therefore, the information signal having the frequency f1 carried by the signal having the frequency ⁇ f can be easily extracted.
- the fourth embodiment described above has the following effect (F).
- F the frequency of the digital signal input to the digital-to-analog converter 45 of the hood back loop can be raised in advance at a low frequency, so that the transmission wave due to the zero-order hold effect can be prevented. A decrease in the gain of the food bag can be suppressed.
- the sampling frequency fs can be made low and the cost reduction of hardware and the reduction in power consumption are attained.
- FIG. 8 is a diagram illustrating a configuration of a wireless receiver according to the fifth embodiment.
- symbol is provided to the structure same as the radio
- the radio receiver 30D of this embodiment has a delta-sigma modulator 40D different from the radio receiver 30C of the fourth embodiment shown in FIG.
- the delta sigma modulator 40D of the present embodiment includes forward amplifiers 48-1, 48-2, 48-3, reverse amplifiers 47-1, 47-2 and 47-3, and reverse phase synthesizers 41-2 and 41-3.
- the output side of the receiving antenna 31 is connected to the forward amplifiers 48-1, 48-2, 48-3.
- the output side of the digital / analog converter 45 is connected to the reverse amplifiers 47-1, 47-2, 47-3.
- the output side of the forward amplifier 48-1 is connected to the in-phase input point of the negative phase synthesizer 41-1.
- the output side of the reverse amplifier 47-1 is connected to the negative phase input point of the negative phase synthesizer 41-1.
- the reverse phase synthesizer 41-2 is connected between the resonator 42-1 and the resonator 42-2.
- the output side of the resonator 42-1 and the output side of the forward amplifier 48-2 are connected to the in-phase input point of the negative phase synthesizer 41-2.
- the output side of the reverse amplifier 47-2 is connected to the negative phase input point of the negative phase synthesizer 41-2.
- the reverse phase synthesizer 41-3 is connected between the resonator 42-2 and the analog / digital converter 43.
- the output side of the resonator 42-2 and the output side of the forward amplifier 48-3 are connected to the in-phase input point of the negative phase synthesizer 41-3.
- the output side of the reverse amplifier 47-3 is connected to the negative phase input point of the negative phase synthesizer 41-3.
- the received signal is input to the in-phase input points of the anti-phase synthesizers 41-1, 41-2, 41-3 via the forward amplifiers 48-1, 48-2, 48-3.
- the feedback output of the digital / analog converter 45 is fed to the negative phase input points of the negative phase synthesizers 41-1, 41-2, 41-3 via the reverse amplifiers 47-1, 47-2, 47-3. Added.
- the third-order feedforward control is performed by the forward amplifiers 48-1, 48-2, and 48-3, and the third-order feedback control is performed by the backward amplifiers 47-1, 47-2, and 47-3. . Therefore, the signal transfer function of the delta sigma modulator 40D is expressed by a sixth order function.
- FIG. 8B is a diagram showing the configuration and operation of the radio receiver 30D in the fifth embodiment, and shows the phase characteristics of the signal transfer function of the delta-sigma modulator 40D.
- the horizontal axis indicates the phase ⁇ , and the vertical axis indicates an example of the phase distortion of the signal transfer function STF (Signal Transfer Function).
- phase distortion of the signal transfer function STF is a predetermined positive value.
- phase When the phase is ( ⁇ 0 ⁇ ), it becomes almost zero, and thereafter monotonously decreases to the phase ⁇ .
- the phase distortion of the signal transfer function STF increases when the phase exceeds ⁇ , and becomes almost zero again when the phase is ( ⁇ 0 + ⁇ ).
- the frequency (f0 ⁇ f) corresponds to the phase ( ⁇ 0 ⁇ ).
- the frequency (f0 + ⁇ f) corresponds to the phase ( ⁇ 0 + ⁇ ).
- FIG. 9 is a diagram illustrating an implementation example of a wireless receiver according to the fifth embodiment.
- a power element circuit 64, a high frequency connector 61, and a digital signal connector 62 are mounted on the multilayer printed circuit board 63, and functional element blocks to which the same symbols as those in FIG. 9 are given are electrically connected by analog signal lines 65 and digital signal lines 66. Connected.
- the direct current generated in the power supply circuit 64 is supplied to the active element of the functional element block using a through hole or the like by a power supply line (not shown) provided in the inner layer of the multilayer printed board 63.
- a ground plane (not shown) for the analog signal line 65 and the digital signal line 66 is formed on the inner layer of the multilayer printed circuit board 63, and a strip line is formed by the ground plane and these signal lines to form a signal transmission path. .
- the radio receiver 30D of the multilayer printed circuit board 63 is equipped with a high frequency connector 61 as an input end of a reception wave and a digital signal connector 62 as an output end of a digital signal.
- the delta-sigma modulator 40D shown in FIG. 8 is configured.
- the delta-sigma modulator 40D can be mass-produced using a printed circuit board process and an automatic surface mounting process for components, and is effective in reducing production costs.
- the two carriers are subjected to opposite phase modulation.
- the delta-sigma modulator 40D does not give phase distortion to the two carrier frequencies.
- the radio receiver 30D of the present embodiment makes the phase distortion of the signal transfer function STF of the delta-sigma modulator 40D zero at the carrier frequencies (f0 + ⁇ f) and (f0 ⁇ f) of the two transmission waves. Is possible. Therefore, it is possible to improve the phase modulation sensitivity of the radio receiver 30D.
- the fifth embodiment described above has the following effect (G).
- G According to the delta-sigma modulator 40D of the present embodiment, the phase distortion is suppressed to be small at the carrier frequencies (f0 + ⁇ f) and (f0 ⁇ f) of the two transmission waves. It is possible to improve the phase modulation sensitivity.
- FIGS. 10A and 10B are diagrams illustrating the configuration of a wireless communication system according to the sixth embodiment. Elements similar to those of the wireless communication system of the second embodiment shown in FIGS. 2A and 2B are assigned the same reference numerals.
- FIG. 10A is a diagram illustrating a configuration of a wireless transmitter according to the sixth embodiment.
- the wireless transmitter 10E of this embodiment includes a combiner / distributor 19, a phase shifter 18, and linearly polarized transmission antennas 20b-1, 20b-2.
- the combiner / distributor 19 combines the two input signals and distributes them to the two output sides.
- the phase shifter 18 is, for example, a delay line, and delays the input signal by a time corresponding to a quarter wavelength of the carrier wave frequency f0 and outputs the delayed signal.
- the output sides of the modulators 13-1 and 13-2 are input to the combiner / distributor 19.
- the output side of the combiner / distributor 19 is connected to the transmission antenna 20b-1, and is also connected to the transmission antenna 20b-2 via the phase shifter 18.
- FIG. 10B is a diagram illustrating the configuration of the wireless receiver according to the sixth embodiment.
- the radio receiver 30E of this embodiment includes linearly polarized wave receiving antennas 31b-1 and 31b-2, a phase shifter 37, demodulators 40E-1 and 40E-2, and a receiving side control unit. 34A and a baseband circuit 51A.
- the phase shifter 37 delays the input signal by a time corresponding to a quarter wavelength of the carrier wave frequency f0 and outputs the delayed signal.
- Demodulators 40E-1 and 40E-2 demodulate the input signal at a predetermined carrier frequency.
- the baseband circuit 51A generates an information signal based on the two demodulated signals.
- the output signal of the modulator 13-1 and the output signal of the modulator 13-2 are combined by the combiner / distributor 19 and then divided into two to be phase-shifted.
- the unit 18 adds a phase difference of 90 ° to the frequency f0, and transmits it to the air via two transmitting antennas 20b-1 and 20b-2 which are integral antennas of orthogonally polarized waves.
- the received wave taken from the receiving antenna 31b-1 is demodulated by the demodulator 40E-1 and supplied to the baseband circuit 51A.
- the received wave taken from the receiving antenna 31b-2 is given a phase difference of 90 ° with respect to the frequency f0 by the phase shifter 37, demodulated by the demodulator 40E-2, and supplied to the baseband circuit 51A.
- the transmission antennas 20b-1 and 20b-2 which are linearly polarized integrated antennas orthogonal to each other, are transmitted into the air, the polarization vector is generated at the frequency difference between the two carrier frequencies. A rotating transmission wave can be emitted, and the rotation angle of the polarization vector of this transmission wave can be detected by the receiver.
- the transmission antennas 20b-1, 20b-2 and the reception antennas 31b-1, 31b-2 can be integrated to reduce the size. It is.
- the sixth embodiment described above has the following effect (H).
- H Compared to the wireless communication system of the second embodiment, the transmission antennas 20b-1 and 20b-2 and the reception antennas 31b-1 and 31b-2 can be integrated to reduce the size. It is.
- FIGS. 11A and 11B are diagrams illustrating the configuration of a wireless communication system according to the seventh embodiment. The same elements as those in the wireless communication system according to the sixth embodiment shown in FIG.
- the wireless transmitter 10F illustrated in FIG. 11A includes transmitting antennas 20c-1 and 20c-2 that are circularly polarized integrated antennas. Other than that, the configuration is the same as that of the wireless transmitter 10E of the sixth embodiment.
- the wireless receiver 30F illustrated in FIG. 11B includes receiving antennas 31c-1 and 31c-2 that are circularly polarized integrated antennas. Others have the same configuration as the wireless receiver 30E of the sixth embodiment.
- the transmitting antennas 20b-1, 20b-2 and the receiving antennas 31b-1, 31b-2 are circularly polarized antennas having different rotation directions.
- a right-hand circularly knitted wave antenna and a left-hand circularly polarized antenna need only be bonded together, and the relative position accuracy between the two antennas need not be considered. Therefore, it is not necessary to consider the pasting accuracy in the mass production process, so that the cost of the antenna can be reduced.
- the seventh embodiment described above has the following effect (I).
- (I) In the mass production process of the transmitting antenna and the receiving antenna, it is not necessary to consider the pasting accuracy of the two antennas, so the cost of the antenna can be reduced.
- FIG. 12 is a diagram showing a configuration of an elevator system in the eighth embodiment.
- the elevator system 100 includes a building 101 that is a vertically long rectangular parallelepiped and an elevator basket 111. Inside the building 101, a space in which the lifting cage 111 is raised and lowered is provided. The elevator cage 111 moves up and down the interior space of the building 101 by a rope and a drive mechanism (not shown).
- a base station radio 102-1 and an antenna 103-1 are installed on the ceiling of the internal space of the building 101, and a base station radio 102-2 and an antenna 103- are installed on the floor of the internal space of the building 101. 2 are installed.
- the base station radio devices 102-1 and 102-2 are radio devices having the same configuration as the radio receiver 30F shown in FIG.
- the antennas 103-1 and 103-2 are integrated reception antennas similar to the reception antennas 31b-1 and 31b-2 shown in FIG.
- An antenna 113-1 is provided on the upper surface of the lifting cage 111, and an antenna 113-2 is provided on the lower surface, and is connected to the terminal station radio 112 by a high-frequency cable 114.
- the terminal station radio 112 is a radio similar to the radio transmitter 10F shown in FIG.
- the antennas 113-1 and 113-2 are integrated transmission antennas similar to the transmission antennas 20c-1 and 20c-2 shown in FIG.
- the radio wave transmitted from the terminal station radio 112 is transmitted via the antenna 113-1 and the antenna 113-2.
- the transmitted radio wave is subjected to multiple reflections by the inner wall of the building 101 and the outer wall of the elevating basket 111 because the internal space of the building 101 is used as a wireless transmission medium. That is, the internal space of the building 101 forms a multiwave interference environment.
- the radio waves that have received multiple reflections reach antennas 103-1 and 103-2, respectively.
- high-quality wireless transmission can be realized even in a multi-wave interference environment. Since the elevator basket 111 can be controlled / monitored from the building 101 by wireless connection means, a space in which the elevator basket 111 is raised and lowered by wired connection means such as a cable is not wasted. Therefore, it is possible to improve the transportation capacity by making the building 101 a small volume or increasing the size of the elevating cage 111 with the same building 101 volume.
- the lifting cage 111 can be reduced in weight. This is because the weight of wired connection means such as a cable connected to the elevator cage 111 is a weight that cannot be ignored in high-rise buildings.
- the eighth embodiment described above has the following effect (J).
- FIG. 13 is a diagram illustrating a configuration of a substation equipment monitoring system according to the ninth embodiment.
- the substation equipment monitoring system 200 includes a plurality of substations 201-1 to 201-12 and a plurality of radio base stations 211-1 to 211-4 set in the vicinity thereof.
- the number of transformers 201-1 to 201-12 is greater than the number of radio base stations 211-1 to 211-4.
- Each of the transformers 201-1 to 201-12 includes a terminal station radio 203 and an orthogonal polarization integrated antenna 202.
- the dimensions of the transformers 201-1 to 201-12 are on the order of several meters.
- Each of the radio base stations 211-1 to 211-4 includes a base station radio 213 and an orthogonal polarization integrated antenna 212.
- the dimensions of the transformers 201-1 to 201-12 are overwhelmingly larger than the wavelength of electromagnetic waves having a frequency of several hundreds of MHz to several GHz used by the radio equipment. (Operation of the ninth embodiment)
- the electromagnetic waves are subjected to multiple reflections by the plurality of substations 201-1 to 201-12.
- a multi-wave interference environment is formed.
- the terminal station radio 203 and the base station radio 213 according to the present embodiment can realize high-quality radio transmission even in a multi-wave interference environment.
- Remote control and remote monitoring of the electric machines 201-1 to 201-12 are possible. Therefore, it is possible to solve the problem of high-voltage induced power, which is a problem when using a cable or the like, eliminates the cost of laying the cable, improves the safety of the control / monitoring system of the substations 201-1 to 201-12, and Cost reduction is possible.
- the ninth embodiment described above has the following effect (K).
- K According to the wireless device of the present embodiment, high-quality wireless transmission can be realized even in a multi-wave interference environment. Control and monitoring of the substations 201-1 to 201-12 can be performed remotely by a plurality of radio base stations 211-1 to 211-4. Therefore, it is possible to solve the problem of high-voltage induced power that becomes a problem when the wired connection means such as a cable is used, and it is possible to eliminate the cost of laying the cable, and the safety of the control / monitoring system for the substations 201-1 to 201-12 Improvement and cost reduction are possible.
- the transmission antennas 20-1 and 20-2 and the reception antenna 31 of the first to fifth embodiments are both linearly polarized antennas.
- the present invention is not limited to this, and a circularly polarized antenna may be used.
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Abstract
Description
すなわち、本発明の無線送信機は、所定周波数の帯域を有する情報信号によって変調が施された第1の搬送周波数を有する第1の送信波と、前記情報信号によって変調が施された第2の搬送周波数を有する第2の送信波を送信する無線送信機であって、前記第1の搬送周波数と前記第2の搬送周波数の平均周波数を一定とし、前記第1の搬送周波数と前記第2の搬送周波数を可変とすることを特徴とする。
その他の手段については、発明を実施するための形態のなかで説明する。
図1(a)~(d)は、第1の実施形態に於ける無線通信システムの構成を示す図である。図1(a)は、本実施形態の無線送信機10を示している。図1(b)は、本実施形態の無線受信機30を示している。図1(c)は、本実施形態の無線送信機10の送信信号のパワースペクトラムを示している。図1(d)は、ローパスフィルタ35の出力信号のパワースペクトラムを示している。
本実施形態の無線通信システムは、無線送信機10と無線受信機30とを有している。
情報生成回路11は、情報信号を生成する。ベースバンド回路17は、入力された情報信号を、所定周波数である周波数帯域f1を有する情報信号に変換する。
可変発振器12-2は、周波数f0から、送信側制御部14の出力信号に応じた周波数差Δfを減算した周波数(f0-Δf)である第2の搬送波を出力する。
図1(b)に示す無線受信機30は、受信アンテナ31と、ミキサ32と、発振器33と、ローパスフィルタ35と、アナログ・デジタル変換器36と、ベースバンド回路51とを有している。
周波数差Δbは、周波数Δfが最も大きい場合に於ける、送信アンテナ20-1,20-2から放射される電磁波のパワースペクトラムのピークの差である。
周波数差Δaは、周波数Δfが最も小さい場合に於ける、送信アンテナ20-1,20-2から放射される電磁波のパワースペクトラムのピークの差である。
本実施形態では、受信アンテナ31からミキサ32に出力された信号のパワースペクトラムは、ミキサ32によって、ピークの周波数差に相当する周波数にプロダクト検波される。よって、ローパスフィルタ35の出力信号のパワースペクトラムは、周波数Δb/2~周波数Δa/2にピークを有している。
図1(a)を元に、本実施形態の無線送信機10の動作を説明する。
情報生成回路11は、情報信号を生成してベースバンド回路17に出力する。ベースバンド回路17は、入力された情報信号を、所定周波数である周波数帯域f1を有する情報信号に変換し、変調器13-1,13-2に出力する。変調器13-1は、可変発振器12-1が出力する発振信号によって、周波数帯域f1を有する情報信号を変調し、送信アンテナ20-1から送信する。変調器13-2は、可変発振器12-2が出力する発振信号によって、周波数帯域f1を有する情報信号を変調し、送信アンテナ20-2から送信する。
送信アンテナ20-1,20-2が送信する直線偏波は、受信アンテナ31によって受信される。受信信号には、周波数(f0±Δf)の周波数の信号が含まれている。この受信信号と、発振器33が出力する周波数f0の発振信号は、ミキサ32で混合される。これにより、プロダクト検波が行われ、両者の周波数差に相当する周波数Δfの信号が取り出される。ミキサ32の出力信号は、ローパスフィルタ35によって、所定周波数以上の信号(ノイズ)が抑圧され、周波数Δfの信号スペクトルが取り出される。ローパスフィルタ35の出力信号は、アナログ・デジタル変換器36を介して、デジタル信号に変換される。このデジタル信号は、ベースバンド回路51によって元の情報信号に変換される。
以上説明した第1の実施形態では、次の(A),(B)のような効果がある。
(A) 本実施形態の無線送信機10は、送信アンテナ20-1,20-2から異なる周波数を有する2つの電磁波を送信している。これにより、回転周期を時間軸上で分割し、分割後の各点での受信波の電力を観測すると、分割後の各点の集合は、受信点で反射波が逆相で合成され受信電力が相殺される時間点と、受信点で反射波が同相で合成され受信電力が強めあう時間点とを含んでいる。デジタル信号処理技術などによって、この受信点で反射波が同相で合成されて、受信電力が強めあう時間点を抽出することによって、反射物が多数存在する電波環境下においても、無線通信路の確保が容易となる。
図2(a)~(d)は、第2の実施形態に於ける無線通信システムの構成を示す図である。図1(a)~(d)に示す第1の実施形態の無線通信システムと同一の要素には同一の符号を付与している。
図2(a)に示す無線送信機10は、図1(a)に示す第1の実施形態の無線送信機10と同様の構成を有している。
図3(a)~(h)は、第2の実施形態に於ける無線通信システムの動作を示す図である。
図3(a)は、無線送信機10がトレーニングモードと通信モードを繰り返す所定シーケンスを示している。図3(b)は、無線受信機30Aがトレーニングモードと通信モードを繰り返す所定シーケンスを示している。図3(a),(b)の横軸は、共通する時間tを示している。
通信モードに於いて、無線送信機10と無線受信機30Aとは、最適な発振周波数Δfiと、最適な受信周波数Δfiによって、情報を送受信する。
図4と異なる点は、異なる中心周波数f0aと、中心周波数f0bとが、周波数帯域の内部に設定されていることである。本実施形態に於ける無線通信システムは更に、中心周波数f0aから周波数軸上に等間隔に位置している周波数(f0a+Δf1)の通信チャネルと、周波数(f0a-Δf1)の通信チャネルを使用する。同時に、中心周波数f0bから周波数軸上に等間隔に位置している周波数(f0b+Δf1)の通信チャネルと、周波数(f0b-Δf1)の通信チャネルを使用する。このように、同時に同一のチャネルを使用せず、かつ、複数の中心周波数f0a,f0bから周波数軸上に等間隔に位置する2つの通信チャネルをそれぞれ選択することにより、複数の無線回線を同時に実現可能となり、情報通信容量増大および無線通信回線の信頼性向上に効果がある。
以上説明した第2の実施形態では、次の(C),(D)のような効果がある。
(C) 本実施形態の無線通信システムは、周波数分割多重を行う既存の無線通信システムに対し、電波法に則った上で、本実施形態を適用可能である。
(D) 同時に同一のチャネルを使用せず、かつ、複数の中心周波数f0a,f0bから周波数軸上に等間隔に位置する2つの通信チャネルをそれぞれ選択することにより、複数の無線回線を同時に実現可能となり、情報通信容量増大および無線通信回線の信頼性向上に効果がある。
図6(a),(b)は、第3の実施形態に於ける無線受信機の構成を示す図である。図1(b)に示す第1の実施形態の無線受信機30と同一の構成には同一の符号を付与している。
アナログ・デジタル変換器43は、例えば、所定の閾値と入力信号とを比較して、1ビットのデジタルに変換する。発振器44は、周波数fsの発振信号を出力する。デジタル・アナログ変換器45は、例えば、1ビットのデジタル信号に応じて所定のアナログ値に変換する。
図6(a)を元に無線受信機30Bの動作を説明する。
デジタル・アナログ変換器45は、フィードバック信号を逆相合成器41-1に出力する。逆相合成器41-1によって、受信アンテナ31が出力する受信信号から、フィードバック信号が減算される。逆相合成器41-1の出力信号は、並列に接続された共振器42-1,42-2を介して、それぞれの共振周波数で共振する。これにより、周波数f0よりも高い周波数によるノイズを除去可能である。
f0=M×fs ・・・(式1)。
このデルタ・シグマ変調器40は、入力信号の微分値(変化量)に応じて、ビット「1」の時間密度が濃くなるようなデジタル信号を出力する。
以上説明した第3の実施形態では、次の(E)のような効果がある。
(E) 本実施形態のデルタ・シグマ変調器40によれば、アナログ非線形回路であるミキサ32および発振器33を用いることなく、送信波よりも充分に低い周波数を中心周波数とする変調信号波をデジタル信号として取り出すことができる。これにより、後段のベースバンド回路51が行うデジタル信号処理により、容易に受信点で反射波が同相に合成される時間点を抽出することが可能であり、無線受信機30Bの簡略化および高信頼化が実現可能である。
図7(a),(b)は、第4の実施形態に於ける無線受信機の構成を示す図である。図6に示す第3の実施形態の無線受信機と同一の要素には同一の符号を付与している。
図7に示す第4の実施形態の無線受信機30Cが、図6に示す第3の実施形態の無線受信機30Bと異なる点は、デルタ・シグマ変調器40Cが用いるデジタル・アナログ変換器45のサンプリング周波数fsをアナログ・デジタル変換器43のサンプリング周波数(M×fs)の整数倍にしており、アナログ・デジタル変換器43のデジタル出力をフィードバックループに戻す際に、デジタル信号補間器46により、デジタル信号の周波数を整数倍にすることである。
以上説明した第4の実施形態では、次の(F)のような効果がある。
(F) 本実施形態によれば、フードバックループのデジタル・アナログ変換器45に入力するデジタル信号の周波数を、低域周波数に於いてあらかじめ持ち上げることができるので、ゼロ次ホールド効果による送信波に対するフードバックのゲインの低下を抑制できる。これにより、図6に示す第3の実施形態のデルタ・シグマ変調器40と比べ、サンプリング周波数fsを低くすることができ、ハードウェアの低価格化および低消費電力化が可能となる。
図8は、第5の実施形態に於ける無線受信機の構成を示す図である。図7に示す第4の実施形態の無線受信機と同一の構成には同一の符号が付与されている。
順方向増幅器48-1,48-2,48-3には、受信アンテナ31の出力側が接続されている。
逆方向増幅器47-1,47-2,47-3には、デジタル・アナログ変換器45の出力側が接続されている。
多層プリント基板63の上に、電源回路64と高周波コネクタ61とデジタル信号コネクタ62が実装され、図9と同一の記号が付与された機能素子ブロックが、アナログ信号線65およびデジタル信号線66によって電気的に接続されている。電源回路64で発生した直流電流は、多層プリント基板63の内層に設けられた図示しない電源線によって、スルーホール等を用いて機能素子ブロックの能動素子に供給される。多層プリント基板63の内層には、アナログ信号線65およびデジタル信号線66に対する図示しないグランド面が形成され、このグランド面とこれらの信号線によりストリップ線路が形成され、信号の伝達路が形成される。
(第5の実施形態の動作)
以上説明した第5の実施形態では、次の(G)のような効果がある。
(G) 本実施形態のデルタ・シグマ変調器40Dによれば、2つの送信波のそれぞれの搬送周波数(f0+Δf),(f0-Δf)で位相歪みが小さく抑制されるので、無線受信機30Dの位相変調感度を向上させることが可能である。
図10(a),(b)は、第6の実施形態に於ける無線通信システムの構成を示す図である。図2(a),(b)に示す第2の実施形態の無線通信システムと同様な要素には同一の符号を付与している。
図10(a)は、第6の実施形態に於ける無線送信機の構成を示す図である。
本実施形態の無線受信機30Eは、相互に直交する直線偏波の受信アンテナ31b-1,31b-2と、移相器37と、復調器40E-1,40E-2と、受信側制御部34Aと、ベースバンド回路51Aとを有している。
図10(a),(b)の第6の実施形態の無線通信システムの動作のうち、図2に示す第2の実施形態の無線通信システムの動作と同一の部分については、説明を省略する。
以上説明した第6の実施形態では、次の(H)のような効果がある。
(H) 第2の実施形態の無線通信システムと比べて、送信アンテナ20b-1,20b-2、および、受信アンテナ31b-1,31b-2を其々一体化することにより、小型化が可能である。
図11(a),(b)は、第7の実施形態に於ける無線通信システムの構成を示す図である。図10に示す第6の実施形態の無線通信システムと同一の要素には同一の符号を付与している。
第6の実施形態の送信アンテナ20b-1,20b-2,受信アンテナ31b-1,31b-2のように、二つの直交する直線偏波のアンテナを制作する際には、厳密に直交する直線状の導体を物理的に実現する必要がある。この直線偏波のアンテナを製造する上で、厳密に直交するように精度を維持することは事実上困難である。
本実施形態では、送信アンテナ20b-1,20b-2,受信アンテナ31b-1,31b-2は、回転方向の異なる円偏波のアンテナである。これを製造するには、右旋円編波アンテナと左旋円偏波アンテナを単に貼り合せれば良く、2つのアンテナの相対位置の精度は考慮しなくとも良い。したがって、量産プロセスに於いて、貼付精度は考慮しなくとも良いため、アンテナの低コスト化が可能である。
以上説明した第7の実施形態では、次の(I)のような効果がある。
(I) 送信アンテナと受信アンテナの量産プロセスに於いて、2つのアンテナの貼付精度は考慮しなくとも良いため、アンテナの低コスト化が可能である。
図12は、第8の実施形態に於ける昇降機システムの構成を示す図である。
この昇降機システム100は、縦長の直方体である建物101と、昇降カゴ111とを有している。建物101の内部には、昇降カゴ111が昇降する空間が設けられている。昇降カゴ111は、図示しないロープと駆動機構によって、建物101の内部空間を昇降する。
端末局無線機112から送信された電波は、アンテナ113-1とアンテナ113-2を介して送信される。送信された電波は、建物101の内部空間を無線伝送媒体とするので、建物101の内壁および昇降カゴ111の外壁によって多重反射を受ける。すなわち、建物101の内部空間は、多重波干渉環境を形成する。多重反射を受けた電波は、それぞれアンテナ103-1,103-2に到達する。
以上説明した第8の実施形態では、次の(J)のような効果がある。
(J) 建物101から無線接続手段によって昇降カゴ111の制御/監視が可能となるので、ケーブル等の有線接続手段によって昇降カゴ111が昇降する空間を無駄にすることがなくなる。よって、小さい建物101の体積とするか、または、同一の建物101の体積で昇降カゴ111の寸法を増大させて輸送能力を向上させることが可能である。
図13は、第9の実施形態に於ける変電設備監視システムの構成を示す図である。
本実施形態の変電設備監視システム200は、複数の変電機201-1~201-12と、これらの近傍に設定されている複数の無線基地局211-1~211-4とを備えている。本実施形態では、変電機201-1~201-12の数は無線基地局211-1~211-4の数よりも多い。
(第9の実施形態の動作)
以上説明した第9の実施形態では、次の(K)のような効果がある。
(K) 本実施形態の無線機によれば、多重波干渉環境下でも高品質の無線伝送が実現可能となる。変電機201-1~201-12の制御・監視を複数の無線基地局211-1~211-4によって遠隔で実施可能である。よって、ケーブルなどの該有線接続手段を用いる場合に問題となる高圧誘導電力の問題を解決できると共に、ケーブルの敷設コストを削除でき、変電機201-1~201-12の制御/監視システムの安全性向上、および、コスト削減が可能となる。
本発明は、上記実施形態に限定されることなく、本発明の趣旨を逸脱しない範囲で、変更実施が可能である。この利用形態や変形例としては、例えば、次の(a)のようなものがある。
11 情報生成回路
12-1,12-2 可変発振器
13-1,13-2 変調器
17 ベースバンド回路
20-1,20-2 送信アンテナ
30,30A,30B,30C,30D,30E,30F 無線受信機
31 受信アンテナ
32 ミキサ
33 発振器
34 受信側制御部
35 ローパスフィルタ
35A 可変バンドパスフィルタ
36 アナログ・デジタル変換器
40,40C,40D デルタ・シグマ変調器
41-1,41-2,41-3 逆相合成器
42-1,42-2 共振器
43 アナログ・デジタル変換器
44 発振器
45 デジタル・アナログ変換器
46 デジタル信号補間器
47-1~47-3 逆方向増幅器
48-1~48-3 順方向増幅器
51 ベースバンド回路
100 昇降機システム
200 変電設備監視システム
Claims (11)
- 所定周波数の帯域を有する情報信号によって変調が施された第1の搬送周波数を有する第1の送信波と、
前記情報信号によって変調が施された第2の搬送周波数を有する第2の送信波を送信する無線送信機であって、
前記第1の搬送周波数と前記第2の搬送周波数の平均である平均周波数を一定とし、前記第1の搬送周波数と前記第2の搬送周波数との差分である差分周波数を可変とする
ことを特徴とする無線送信機。 - 複数のチャネルに分割された周波数帯域から前記第1の搬送周波数と前記第2の搬送周波数を選択することによって、前記第1の搬送周波数と前記第2の搬送周波数を可変とし、
第1の送信アンテナを用いて前記第1の送信波を送信し、
第2の送信アンテナを用いて前記第2の送信波を送信する
こと特徴とする請求の範囲第1項に記載の無線送信機。 - 前記第1の送信波と前記第2の送信波の複数の組合せによって、それぞれ異なる前記情報信号を伝送することを特徴とする請求の範囲第2項に記載の無線送信機。
- 請求の範囲第1項ないし請求の範囲第3項のいずれか1項に記載の無線送信機が送信する前記第1の送信波と前記第2の送信波とを受信して前記差分周波数を検波し、前記差分周波数によって搬送された所定周波数の帯域を有する前記情報信号を復調する
ことを特徴とする無線受信機。 - 請求の範囲第1項ないし請求の範囲第3項のいずれか1項に記載の無線送信機の受信信号が入力され、前記第1の搬送周波数を共振周波数とする第1の共振器と、
前記受信信号が入力され、前記第2の搬送周波数を共振周波数とする第2の共振器と、
前記第1の共振器の出力信号と前記第2の共振器の出力信号とを前記平均周波数の周波数でサンプリングするアナログ・デジタル変換器と、
前記アナログ・デジタル変換器によってサンプリングされた信号を補間するデジタル信号補間器と、
前記デジタル信号補間器の出力信号を、前記平均周波数の整数倍の周波数で変換するデジタル・アナログ変換器と、
前記受信信号から前記デジタル・アナログ変換器の出力信号を逆相で合成する逆相合成器と、
を具備するデルタ・シグマ変調器によって、前記差分周波数で検波する
こと特徴とする無線送信機、 - 前記デルタ・シグマ変調器の信号伝達関数の位相が、前記第1の搬送周波数と前記第2の搬送周波数において、ほぼゼロであることを特徴とする請求の範囲第5項に記載の無線送信機。
- 前記第1の共振器、前記第2の共振器、前記アナログ・デジタル変換器、前記デジタル信号補間器、前記デジタル・アナログ変換器、および、前記逆相合成器が実装されたプリント基板を具備する
ことを特徴とする請求の範囲第5項に記載の無線送信機。 - 請求の範囲第1項に記載の無線送信機、および、請求の範囲第5項に記載の無線送信機を有する無線通信システムであって、
前記無線送信機は、所定シーケンスに従って前記差分周波数を可変し、
前記無線受信機は、所定シーケンスに従って検波する検波周波数を可変して最も変換出力が高い前記差分周波数と前記検波周波数との組合せを検出し、
前記所定周波数の帯域を有する前記情報信号を復調する
ことを特徴とする無線通信システム。 - 前記所定シーケンスは、トレーニングモードと通信モードを含み、
前記トレーニングモードに於いては、前記無線送信機は前記差分周波数を可変させながら、前記無線受信機に於いて最も受信感度が高い前記差分周波数を選別し、
前記通信モードに於いて、前記無線送信機と前記無線受信機は、前記差分周波数に対応する前記第1の搬送周波数と前記第2の搬送周波数とを用いて通信を行う
ことを特徴とする請求の範囲第8項に記載の無線通信システム。 - 請求の範囲第8項または請求の範囲第9項に記載の無線通信システムを備えることを特徴とする昇降機制御システム。
- 請求の範囲第8項または請求の範囲第9項に記載の無線通信システムを備えることを特徴とする変電設備制御システム。
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GB1322270.8A GB2507204B (en) | 2011-06-01 | 2011-06-01 | Wireless transmitter, wireless receiver, wireless communications system, elevator control system, and transformer equipment control system |
US14/122,924 US9219506B2 (en) | 2011-06-01 | 2011-06-01 | Wireless transmitter, wireless receiver, wireless communication system, elevator control system, and transformer equipment control system |
JP2013517755A JP5753580B2 (ja) | 2011-06-01 | 2011-06-01 | 無線送信機、無線受信機、無線通信システム、昇降機制御システムおよび変電設備制御システム |
PCT/JP2011/062576 WO2012164697A1 (ja) | 2011-06-01 | 2011-06-01 | 無線送信機、無線受信機、無線通信システム、昇降機制御システムおよび変電設備制御システム |
CN201180071263.6A CN103563258B (zh) | 2011-06-01 | 2011-06-01 | 无线发送机、无线接收机、无线通信系统、升降机控制系统以及变电设备控制系统 |
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2011
- 2011-06-01 WO PCT/JP2011/062576 patent/WO2012164697A1/ja active Application Filing
- 2011-06-01 JP JP2013517755A patent/JP5753580B2/ja not_active Expired - Fee Related
- 2011-06-01 GB GB1322270.8A patent/GB2507204B/en not_active Expired - Fee Related
- 2011-06-01 CN CN201180071263.6A patent/CN103563258B/zh not_active Expired - Fee Related
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JP2007251989A (ja) * | 2000-12-13 | 2007-09-27 | Eudyna Devices Inc | 送信装置及び受信装置 |
WO2006049127A1 (ja) * | 2004-11-02 | 2006-05-11 | Ntt Docomo, Inc. | 基地局、無線回線制御局及び無線通信方法 |
JP2007221303A (ja) * | 2006-02-15 | 2007-08-30 | Mitsubishi Electric Corp | 衛星通信アンテナ装置 |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
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WO2014155470A1 (ja) * | 2013-03-25 | 2014-10-02 | 株式会社 日立製作所 | 無線送信機、無線通信システム、昇降機制御・監視システム、および、変電設備制御・監視システム |
JP5868546B2 (ja) * | 2013-03-25 | 2016-02-24 | 株式会社日立製作所 | 無線通信システム、昇降機制御・監視システム、および、変電設備制御・監視システム |
Also Published As
Publication number | Publication date |
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JPWO2012164697A1 (ja) | 2014-07-31 |
GB2507204A (en) | 2014-04-23 |
GB201322270D0 (en) | 2014-01-29 |
GB2507204B (en) | 2017-10-18 |
US9219506B2 (en) | 2015-12-22 |
CN103563258B (zh) | 2015-04-15 |
CN103563258A (zh) | 2014-02-05 |
US20140112409A1 (en) | 2014-04-24 |
JP5753580B2 (ja) | 2015-07-22 |
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