JP6015714B2 - Receiver, receiving system, receiving method, and receiving program - Google Patents

Description

  The present invention relates to a receiver, a receiving system, a receiving method, and a receiving program that appropriately receive radio waves transmitted from each transmitting antenna and arrived and extract data.

  There are receivers that simultaneously receive radio waves respectively transmitted from transmitting antennas of reporting stations scattered throughout the country via a geostationary communication satellite. The radio waves transmitted from the transmitting antennas of the reporting stations scattered throughout the region are affected by the climate of each region during propagation. Further, the frequency of the radio wave is shifted by Doppler shift by being relayed by the geostationary communication satellite. Therefore, the frequency of the radio wave transmitted from each transmitting antenna of each reporting station is unstable when it reaches the receiver via the geostationary communication satellite.

  Such a receiver receives the radio wave transmitted from each transmission antenna as a radio wave including a plurality of signal components of channels having different frequencies. The receiver is provided with a number of demodulation modules corresponding to the number of channels in order to extract data included in the signal components.

  Patent Document 1 describes a terrestrial digital television broadcast receiving apparatus including an FFT operation unit for performing demodulation (Fast Fourier Transform) processing on a received signal. In the digital terrestrial television broadcast receiving apparatus described in Patent Literature 1, the FFT calculation unit divides the received signal into a plurality of channels according to a predetermined frequency, and performs deinterleaving processing and decoding processing.

JP 2012-90080 A

  Radio waves transmitted from each transmitting antenna of each reporting station and reaching the receiver via the geostationary communication satellite are shifted outside the specified frequency range due to the influence of the climate in each region and Doppler shift. There may be. In such a case, since the radio wave cannot be detected in a specified frequency range, the receiver cannot extract data from the radio wave.

  Therefore, the receiving device described in Patent Document 1 cannot extract data from radio waves transmitted from each transmitting antenna of each reporting station at a specified frequency and reaching the receiver via a stationary communication satellite. There is.

  Moreover, since it is necessary to prepare a dedicated demodulation module for each channel to be received in the receiver, there is a problem that the cost is increased, and volume (for example, FPGA (Field-Programmable Gate Array)) There is a problem that the capacity required when configuring the demodulation module is increased.

  Therefore, the present invention provides a receiver, a receiving system, a receiving method, and a receiving program that can appropriately receive radio waves transmitted from each transmitting antenna at a specified frequency and reach a receiver and extract data. The purpose is to do.

  A receiver according to the present invention includes Fourier transform processing means for performing Fourier transform processing on a digital signal based on an analog signal respectively transmitted from a plurality of transmitting antennas installed at locations separated from each other and received by the receiving antenna, and Fourier transform processing means Based on the processing result of the conversion processing means, a detection signal generation means for generating a detection signal for synchronous detection of the digital signal, and a detection means for synchronous detection of the digital signal using the detection signal generated by the detection signal generation means And data extraction means for extracting data from the digital signal based on the detection result by the detection means.

  The receiving system according to the present invention includes an amplifying unit for amplifying an analog signal transmitted from each of a plurality of transmitting antennas installed at locations separated from each other and received by the receiving antenna, and a frequency of the analog signal amplified by the amplifying unit. It is characterized by comprising a frequency conversion means for converting the signal, a signal whose frequency is converted by the frequency conversion means, and a receiver in any form.

  The reception method according to the present invention includes a Fourier transform processing step of performing a Fourier transform process on a digital signal based on an analog signal respectively transmitted from a plurality of transmitting antennas installed at locations separated from each other and received by the receiving antenna, Based on the processing result of the conversion processing step, a detection signal generation step for generating a detection signal for synchronous detection of the digital signal, and a detection step for synchronous detection of the digital signal using the detection signal generated in the detection signal generation step And a data extraction step of extracting data from the digital signal based on the detection result of the detection step.

  The reception program according to the present invention is a Fourier transform processing step for performing a Fourier transform process on a digital signal based on an analog signal respectively transmitted from a plurality of transmitting antennas installed at locations separated from each other and received by a receiving antenna. And a detection signal generation step for generating a detection signal for synchronous detection of the digital signal based on the processing result of the Fourier transform processing step, and a detection of the digital signal using the detection signal generated in the detection signal generation step. And a data extraction step of extracting data from the digital signal based on the detection result of the detection step.

  According to the present invention, it is possible to appropriately receive radio waves transmitted from each transmitting antenna at a specified frequency and arrive and extract data.

It is explanatory drawing which shows the structural example of the receiving system of the 1st Embodiment of this invention. It is a block diagram which shows the structural example of the receiver in the 1st Embodiment of this invention. It is a flowchart which shows operation | movement of the receiver in the 1st Embodiment of this invention. It is explanatory drawing which shows the structural example of the receiver of the 2nd Embodiment of this invention.

Embodiment 1. FIG.
A reception system 400 according to the first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is an explanatory diagram illustrating a configuration example of a reception system 400 according to the first embodiment of this invention. As shown in FIG. 1, the reception system 400 according to the first embodiment of the present invention includes a low noise amplifier 410, a down converter 420, and a receiver 430.

  The low noise amplifier 410 amplifies the signal transmitted by the transmission antennas 100 a to 100 c and received by the reception antenna 300 via the artificial satellite 200 and inputs the amplified signal to the down converter 420. The down-converter 420 converts the frequency of the signal amplified by the low noise amplifier 420 into an intermediate frequency and inputs it to the receiver 430. Note that the intermediate frequency after conversion by the down converter 420 is, for example, a frequency in the 70 MHz band. The carrier wave of the frequency is modulated by, for example, a PCM-PSK (Pulse Code Modulation-Phase Shift Keying) method or an FM (Frequency Modulation) method.

  The receiver 430 performs predetermined processing on the input signal and outputs the processing result to the display terminal 500 for display.

  FIG. 2 is a block diagram illustrating a configuration example of the receiver 430 according to the first embodiment of the present invention. As illustrated in FIG. 2, the receiver 430 includes an analog-to-digital (A-D) conversion unit 431, an FFT processing unit 432, and a demodulation unit 433.

  As shown in FIG. 2, the demodulation unit 433 includes demodulation units 434a to 434z. Further, the demodulation units 434a to 434z each include a multiplication unit, a low-pass filter unit, a carrier lock unit, a numerically controlled oscillation unit, and a data extraction unit, and are configured in the same manner. In FIG. 2, the demodulation unit 434a, which represents the demodulation unit, includes a multiplication unit 435a, a low-pass filter unit 436a, a carrier lock unit 437a, a numerically controlled oscillation unit 438a, and a data extraction unit 439a. It is shown. Hereinafter, a case where the demodulation unit 434a is mainly used will be described as an example.

  The A-D conversion unit 431 quantizes the analog signal input by the down converter 420 and converts it into a digital signal. Then, the A-D conversion unit 431 inputs the converted digital signal to each multiplication unit of each of the demodulation units 434 a to 434 z and the FFT processing unit 432.

  The FFT processing unit 432 generates frequency information indicating the frequency of the signal component having an intensity equal to or greater than a predetermined threshold in the signal input to the receiver 430 based on the result of performing the FFT process on the input digital signal. Input to the numerically controlled oscillator 438a. For example, when there are n signal components having an intensity equal to or greater than a predetermined threshold, the FFT processing unit 432 applies each of the numerically controlled oscillators from the first demodulator 434a to the nth demodulator. Frequency information indicating the frequency of each signal component is input. Such a configuration makes it possible to detect and demodulate each of the signal components of a plurality of channels included in the received signal.

  Based on the frequency information input by the FFT processing unit 432, the numerical control type oscillation unit 438a inputs a signal having a frequency indicated by the frequency information to the multiplication unit 435a. Note that the signal of the frequency indicated by the frequency information that is input to the multiplier 435a by the numerically controlled oscillator 438a is, for example, a sine wave having the frequency indicated by the frequency information.

  The multiplier 435a multiplies the signal input by the numerically controlled oscillator 438a and the digital signal input by the A / D converter 431, and inputs the processed signal to the low-pass filter 436a. Therefore, in the multiplication unit 435a, the digital signal input by the A / D conversion unit 431 is synchronously detected and input to the low-pass filter unit 436a.

  A high frequency component is removed from the signal input to the low pass filter unit 436a, and the signal is input to the carrier lock unit 437a. The low-pass filter unit 436a is configured to pass a signal in a frequency band equal to or lower than the frequency band of the modulated wave of the signal received by the receiving system 400 and demodulated by the demodulator 434a. The carrier lock unit 437a inputs the input signal to the data extraction unit 439a, and based on the signal, the digital signal input by the A / D conversion unit 431 to the multiplication unit 435a and the numerically controlled oscillation unit 438a The phase difference from the signal input to the multiplier 435a is detected. Based on the detection result, the carrier lock unit 437a causes the numerically controlled oscillation unit 438a to synchronize the signal input to the multiplication unit 435a with the digital signal input to the multiplication unit 435a by the AD conversion unit 431. Instruct. The numerically controlled oscillator 438a synchronizes the signal input to the multiplier 435a with the digital signal input to the multiplier 435a by the A / D converter 431a in response to an instruction from the carrier lock unit 437a.

  The data extraction unit 439a performs processing such as symbol lock or frame lock on the signal input by the carrier lock unit 437a, and extracts data from the signal in predetermined bit units. Then, the data extraction unit 439a transmits the extracted data to the display terminal 500.

  The display terminal 500 displays information based on the data extracted by the data extraction unit 439a.

  Next, the operation of the receiver 430 will be described. FIG. 3 is a flowchart showing the operation of the receiver 430 in the first embodiment of the present invention. In the receiver 430, when an analog signal is input, the AD converter 431 converts the input analog signal into a digital signal (step S101). The A-D conversion unit 431 inputs the converted digital signal to the multiplication unit 435 a and the FFT processing unit 432.

  The FFT processing unit 432 performs FFT processing on the input digital signal (step S102). Then, the FFT processing unit 432 generates frequency information based on the result of the FFT processing (step S103) and inputs the frequency information to the numerically controlled oscillation unit 438a.

  The numerically controlled oscillator 438a inputs the sine wave having the frequency indicated by the frequency information generated in the process of step S103 to the multiplier 435a (step S104).

  The multiplication unit 435a performs synchronous detection that multiplies the sine wave input in the process of step S104 and the digital signal input by the A / D conversion unit 431 (step S105), and processes the signal of the processing result as a low-pass filter. This is input to the part 436a.

Based on the signal from which the high-frequency component has been removed by the low-pass filter unit 436a, the carrier lock unit 437a includes a digital signal input to the multiplication unit 435a by the A / D conversion unit 431, and a multiplication unit configured by the numerically controlled oscillation unit 438a. The phase difference from the signal input to 435a is detected (steps S106 and S107).
Then, based on the detection result of the phase difference by the carrier lock unit 437a, the numerically controlled oscillator 438a synchronizes the signal input to the multiplier 435a with the digital signal input to the multiplier 435a by the A / D converter 431. (Step S108).

  Further, the carrier lock unit 437a inputs the signal that has passed through the low-pass filter unit 436a to the data extraction unit 439a. The data extraction unit 439a extracts data from the signal input by the carrier lock unit 437a (step S109). The data extracted by the data extraction unit 439a is displayed by the display terminal 500.

  According to the present embodiment, the FFT processing unit 432 generates frequency information based on the analog signal received by the receiving antenna 300. Further, the analog signal is converted into a digital signal, and is detected and demodulated by a signal generated by the numerically controlled oscillator 438a according to the frequency information. Therefore, even if the frequency of the analog signal received by the receiving antenna 300 is shifted, it is possible to extract data included in the analog signal corresponding to the shift.

  In addition, according to the present embodiment, in order to correspond respectively to the signal components of a plurality of channels having different frequencies (for example, M channels based on radio waves respectively transmitted from M transmission antennas), each channel corresponds to each channel. Data included in the signal component of each channel can be extracted without preparing a dedicated demodulation module. In order to support simultaneous reception of signal components of a plurality of channels (for example, N channels, where M ≧ N) included in the signal, the number of demodulation units (the number of demodulation units (the number of channels received simultaneously) ( For example, N demodulation units) may be prepared. Therefore, the number of demodulation units prepared in the receiver 430 can be reduced. Therefore, the cost of the receiver 430 can be reduced. Further, the volume of the receiver 430 can be reduced.

Embodiment 2. FIG.
A receiver 40 according to a second embodiment of the present invention will be described with reference to the drawings. FIG. 4 is an explanatory diagram illustrating a configuration example of the receiver 40 according to the second embodiment of this invention. As shown in FIG. 4, the receiver 40 of the second embodiment of the present invention includes a Fourier transform processing unit 42 (corresponding to the FFT processing unit 432a shown in FIG. 1), a detection signal generating unit 48 (the numerical values shown in FIG. 1). Control type oscillating unit 438a), detecting means 45 (corresponding to multiplier 435a shown in FIG. 1), and data extracting means 49 (corresponding to data extracting unit 439a shown in FIG. 1).

  The Fourier transform processing means 42 performs a Fourier transform process on a digital signal based on an analog signal that is transmitted from each of a plurality of transmitting antennas installed at locations separated from each other and received by the receiving antenna. The detection signal generation unit 48 generates a detection signal for synchronous detection of the digital signal based on the processing result of the Fourier transform processing unit 42.

  The detection unit 45 uses the detection signal generated by the detection signal generation unit 48 to synchronously detect the digital signal. The data extraction unit 49 extracts data from the digital signal based on the detection result by the detection unit 45.

  According to the present embodiment, it is possible to appropriately receive radio waves that have been transmitted from each transmitting antenna and transmitted at a specified frequency and extract data.

DESCRIPTION OF SYMBOLS 40 Receiver 42 Fourier-transform processing means 45 Detection means 48 Detection signal generation means 49 Data extraction means 100a, 100b, 100c Transmission antenna 200 Artificial satellite 300 Reception antenna 400 Reception system 410 Low noise amplifier 420 Down converter 430 Receiver 431 AD Conversion unit 432 FFT processing unit 433 demodulation unit 434a, 434b, 434z demodulation unit 435a multiplier 436a low-pass filter unit 437a carrier lock unit 438a numerical control type oscillation unit 439a data extraction unit 500 display terminal

Claims (7)

Fourier transform processing means for performing Fourier transform processing on digital signals based on analog signals respectively transmitted from a plurality of transmitting antennas installed at locations separated from each other and received by receiving antennas,
Detection signal generation means for generating a detection signal for synchronous detection of the digital signal based on the processing result of the Fourier transform processing means;
Detection means for synchronously detecting the digital signal using the detection signal generated by the detection signal generation means;
Data extraction means for extracting data from the digital signal based on the detection result by the detection means ;
Based on a detection result by the detection means, a phase difference between the detection signal and the digital signal in the detection means is detected, and the detection signal is synchronized with the digital signal according to the detection result. A receiver comprising phase difference detection means for instructing generation means . The receiver according to claim 1, comprising a plurality of detection signal generation means, a plurality of detection means, and a plurality of data extraction means. The Fourier transform processing means generates the frequency information indicating the frequency of each signal component when the plurality of signal components having a predetermined intensity or more are detected as a result of performing the Fourier transform processing on the digital signal. Input each into the signal generation means,
Each of the plurality of detection signal generation means generates the detection signal based on the frequency information input by the Fourier transform processing means,
Each of the plurality of detection means performs synchronous detection of the digital signal using the detection signal generated by the corresponding detection signal generation means,
The receiver according to claim 2, wherein each of the plurality of data extraction units extracts data from the digital signal based on a detection result by the corresponding detection unit. The detection signal generation means detects a signal having a frequency of a signal component having a predetermined intensity or higher among signal components included in the analog signal based on a result of Fourier transform processing of the digital signal by the Fourier transform processing means. The receiver according to any one of claims 1 to 3. Amplifying means for amplifying analog signals respectively transmitted from a plurality of transmitting antennas installed at locations separated from each other and respectively received by a receiving antenna;
Frequency conversion means for converting the frequency of the analog signal amplified by the amplification means;
A signal having a frequency converted by the frequency converting means is input, and the receiver according to any one of claims 1 to 4 is provided.
A receiving system. A Fourier transform processing step of performing a Fourier transform process on a digital signal based on an analog signal respectively transmitted from a plurality of transmitting antennas installed at locations separated from each other and received by a receiving antenna;
A detection signal generating step for generating a detection signal for synchronous detection of the digital signal based on the processing result of the Fourier transform processing step;
Using the detection signal generated in the detection signal generation step, the detection step of synchronously detecting the digital signal,
A data extraction step of extracting data from the digital signal based on the detection result of the detection step;
Based on the detection result of the detection step, a phase difference between the detection signal and the digital signal in the detection step is detected, and the detection signal is synchronized with the digital signal according to the detection result. Includes phase difference detection process to be processed in the generation process
And a receiving method. On the computer,
A Fourier transform processing step for performing a Fourier transform process on a digital signal based on an analog signal respectively transmitted from a plurality of transmitting antennas installed at locations separated from each other and received by a receiving antenna;
A detection signal generation step for generating a detection signal for synchronous detection of the digital signal based on the processing result of the Fourier transform processing step;
A detection step of synchronously detecting the digital signal using the detection signal generated in the detection signal generation step;
A data extraction step of extracting data from the digital signal based on the detection result of the detection step;
Based on the detection result of the detection step, a phase difference between the detection signal and the digital signal in the detection step is detected, and the detection signal is synchronized with the digital signal according to the detection result. And a phase difference detection step for executing the generation step.
Receiving program for.

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