JP6080169B2 - Transmission / reception system, transmission device, and reception device - Google Patents

Description

  The present invention relates to a transmission / reception system, a transmission device, and a reception device.

  The configuration of a conventional transmission / reception system is shown in FIG. In FIG. 5, the transmission device 10 includes a coupler 11, oscillators 12 and 14, a multiplier 13, and a mixer 15. The receiving device 20 includes a mixer 21, a frequency divider 22, and oscillators 23 and 24.

Here, the oscillator 12 of the transmission apparatus 10 has “high stability and low phase noise characteristics” with high frequency stability and low phase noise, and generates and outputs a signal of frequency f _Lo1 . The multiplier 13 multiplies the signal output from the oscillator 12 and outputs a signal having a frequency f _pl to the coupler 11. The oscillator 14 multiplies the frequency f _{Lo1 of the} signal Lo1 output from the oscillator 12 by η and supplies it to the mixer 15 as a signal of the frequency f _Lo2 . Coupler 11 is supplied to an input signal having a frequency f _in, the frequency f _pl of the signal supplied from the multiplier 13 to the mixer 15 attached (added) as a pilot signal. The mixer 15 up-converts the input signal combined with the pilot signal output from the combiner 11 with the signal of the frequency f _Lo2 supplied from the oscillator 14 and transmits it as a signal of the frequency f _if .

In the receiving device 20, the mixer 21 receives the signal with the frequency f _if transmitted from the transmitting device 10, down-converts the signal with the frequency f _Lo4 supplied from the oscillator 24, and outputs a signal with the frequency f _pl . The frequency divider 22 extracts a pilot signal included in the output signal and divides the signal by α times (0 <α <= 1) to output a signal having a frequency f _ref . The oscillator 23 multiplies the frequency of the signal output from the frequency divider 22 by β, and outputs a signal having a frequency f _Lo3 . Oscillator 24, multiplies the frequency _{f Lo3} signal Lo3 output from the oscillator 23 gamma, supplied to the mixer 21 as a signal of a frequency _{f Lo4.} In addition, the minute period 22 may include a device that extracts a signal having a frequency f _pl .
The signal relationship is shown below.
f _in = f _out
f _in <f _if
f _Lo1 <f _{Lo2
f Lo3} <f _Lo4
f _re <f _Lo3

With the above configuration, the transmitting apparatus 10 adds the signal of the frequency f _pl generated from the same signal as the signal that generated the up-conversion signal of the frequency f _if as a pilot signal, and transmits the pilot signal. Based on this, a down-conversion signal can be generated. For this reason, since the up-conversion and the down-conversion are performed based on the same signal in the transmission device 10 and the reception device 20, the original signal can be extracted with high accuracy.

  On the other hand, in Patent Document 1, on the transmission side, pilot signals of frequencies fp1s and fp2s whose frequency differences are equal to the reference frequency are added to the main signal, modulated, and transmitted, and on the reception side, the main signal of frequency fIF22 is transmitted. And the frequency fP1r ′ and the pilot signal of the frequency fP2r ′, the reference frequency signal of the frequency fREF2 is reproduced from the frequency difference between the pilot signal of the frequency fP1r ′ and the pilot signal of the frequency fP2r. A pilot signal having a frequency fP2r obtained by modifying the pilot signal having the frequency fP2r ′ is generated, and the pilot signal component is completely removed from the main signal having the frequency fIF22 by the pilot signal having the frequency fP2r. Techniques for obtaining the ingredients are disclosed.

  Further, in Patent Document 2, a predetermined phase value is input, a gain is adjusted and accumulated and output, and a gain value is given to the output value of the loop filter 200, and this value is fed back and added. A voltage-controlled oscillator 300 to be output later, a derotator 400 that obtains a sine wave and a cosine wave and multiplies them by the output signal of the A / D converter 100, and a correlation calculation that calculates and outputs the correlation in units of symbols. Means 600, and an arbitrary frequency offset deviation range is set, a phase signal corresponding to the sequentially generated frequency offset is generated and output to the loop filter 200, and the correlation degree calculating means 600 for the symbols corrected thereby is generated. The approximate value of the frequency offset is finally determined according to the output value, and the frequency is turned off according to the final estimated frequency estimate. Technology consisting of frequency offset estimating means 700. for correcting the Tsu bets is disclosed.

JP 2000-151553 A Japanese Patent Laid-Open No. 10-190613

In the prior art shown in FIG. 5, the mixer 21 of the receiving device 20 downconverts the input signal with the signal of the frequency f _Lo4 from the oscillator 24, and multiplies the pilot signal included in the downconverted signal. _Thus, a signal having a frequency f _Lo4 is generated and supplied to the mixer 21. For this reason, since the pilot signal circulates in the loop constituted by the mixer 21, the frequency divider 22, and the oscillators 23 and 24, the operation of the apparatus may become unstable depending on the phase characteristics and amplitude characteristics of the loop. . In addition, the frequency divider 22 needs to be configured to extract only the pilot signal by excluding the input signal, which causes a problem that the circuit configuration becomes complicated.

  On the other hand, in the technique disclosed in Patent Document 1, since the reference frequency signal is generated from the frequency difference, the operation may become unstable when the frequency becomes high. In addition, the technique disclosed in Patent Document 2 requires a demodulator for extracting a pilot symbol included in an input signal or an output signal, so that the circuit configuration becomes complicated and a delay time is required. There is a problem.

  The present invention has been made in view of the above points, and an object of the present invention is to provide a transmission / reception system, a transmission device, and a reception device that have a simple circuit configuration and high operational stability.

In order to solve the above problems, the present invention provides a transmission / reception system in which a signal including a pilot signal is transmitted from a transmission apparatus to a reception apparatus, wherein the transmission apparatus modulates information by changing signal characteristics of adjacent sections. Modulation means for modulating a signal of a predetermined frequency according to the method, addition means for adding the signal of the predetermined frequency modulated by the modulation means to the input signal as a pilot signal, and the input to which the pilot signal is added Up-converting means for up-converting the frequency of the signal based on the frequency of a reference signal generated from the same signal as the signal of the predetermined frequency; and transmitting means for transmitting the signal up-converted by the up-converting means; And the reception device receives a signal transmitted by the transmission means. Stage and the frequency of the signal received by the receiving means, and down-conversion means for down-converting on the basis of the frequency of the reference signal, and inputs the signal down-converted by the down-conversion means, adjacent the input signal demodulating the pilot signal from the characteristic change of the interval of the signal, the predetermined demodulation means for obtaining a signal of the frequency generation means for supplying to said down-conversion means to generate the reference signal based on the predetermined frequency It is characterized by having.
According to such a configuration, it is possible to provide a transmission / reception system having a simple circuit configuration and high operational stability.

Also, the present invention is characterized in that the modulation means and the demodulation means perform modulation and demodulation based on DPSK (Differential Phase Shift Keying).
According to such a configuration, since modulation and demodulation can be executed based on the phase difference, the operation stability can be further improved with a simple circuit configuration regardless of the transmission path characteristics.

The present invention also relates to a modulation unit that modulates a signal of a predetermined frequency by a modulation method that represents information by a change in signal characteristics of adjacent sections in a transmission device that transmits a signal including a pilot signal to a reception device. Adding means for adding the signal of the predetermined frequency modulated by the modulation means to the input signal as a pilot signal; and the same signal as the signal of the predetermined frequency with the frequency of the input signal to which the pilot signal is added. And an up-conversion means for up-conversion based on the frequency of the reference signal generated from the signal, and a transmission means for transmitting the signal up-converted by the up-conversion means.
According to such a configuration, it is possible to provide a transmission device with high operational stability with a simple circuit configuration.

Further, the present invention provides a receiving apparatus that receives a signal including a pilot signal transmitted from a transmitting apparatus, and modulates a signal having a predetermined frequency by a modulation method that represents information by a change in signal characteristics of adjacent sections. Is added to the input signal as a pilot signal, and the frequency of the input signal to which the pilot signal is added is up-converted based on the frequency of the reference signal generated from the same signal as the signal of the predetermined frequency. Receiving means for receiving a signal transmitted from the transmitting device for transmission; down-converting means for down-converting the frequency of the signal received by the receiving means based on the frequency of the reference signal; and down-converting by the down-converting means The converted signal is input, and the signal characteristics change in the adjacent section of the input signal. Demodulating the pilot signal comprises demodulating means for obtaining a signal of the predetermined frequency, and a generation means for supplying to said down-conversion means to generate the reference signal based on the predetermined frequency.
According to such a configuration, it is possible to provide a reception device with high operational stability with a simple circuit configuration.

  According to the present invention, it is possible to provide a transmission / reception system, a transmission device, and a reception device that have high operational stability with a simple circuit configuration.

It is a figure which shows the structural example of the transmitter of the transmission / reception system which concerns on embodiment of this invention. It is a figure which shows the structural example of the receiver of the transmission / reception system which concerns on embodiment of this invention. It is a figure for demonstrating operation | movement of the transmitter shown in FIG. FIG. 3 is a diagram for explaining the operation of the receiving device shown in FIG. 2. It is a figure which shows the structure of the conventional transmission / reception system.

  Next, an embodiment of the present invention will be described.

(A) Description of Configuration of Embodiment of the Present Invention FIG. 1 is a block diagram showing a configuration example of a transmission apparatus constituting a transmission / reception system according to an embodiment of the present invention, and FIG. It is a block diagram which shows the structural example of the receiver which comprises the transmission / reception system which concerns on a form. As illustrated in FIG. 1, the transmission apparatus 10 includes a coupler 11, oscillators 12 and 14, a mixer 15, a frequency divider 16, and a DPSK (Differential Phase Shift Keying) modulator 18. Here, the coupler 11, the input signal of the frequency f _in supplied from an upper node (not shown) (the main signal), combining the pilot signal supplied from the DPSK modulator 18 (added) to and outputs . The oscillator 12 generates a signal having a frequency f _{Lo1 and supplies} the signal to the oscillator 14, the frequency divider 16, and the clock generator 17. The oscillator 14 is configured by, for example, a PLL (Phase Locked Loop) circuit, _multiplies the frequency f _{Lo1 of} the signal supplied from the oscillator 12 by η, and outputs the signal to the mixer 15 as a signal of the frequency f _Lo2 . The mixer 15 up-converts the signal supplied from the coupler 11 with the signal of the frequency f _Lo2 supplied from the oscillator 14 and outputs it as a signal of the frequency f _if .

The frequency divider 16 _divides the frequency f _Lo1 signal supplied from the oscillator 12 to generate a modulated signal having the frequency f _mpl and outputs the modulated signal to the DPSK modulator 18. The clock generator 17 generates a clock signal having the frequency f _clk from the signal _having the frequency f _Lo1 supplied from the oscillator 12 and outputs the clock signal to the DPSK modulator 18. The DPSK modulator 18 performs DPSK modulation on the modulated signal input from the frequency divider 16 based on the clock signal supplied from the clock generator 17 and outputs the modulated signal to the combiner 11 as a pilot signal. This pilot signal is added by the coupler 11 to the input signal which is the main signal.

  FIG. 2 is a diagram illustrating a configuration example of the receiving device 20. As illustrated in FIG. 2, the receiving device 20 includes a mixer 21, oscillators 23 and 24, a synchronization circuit 30, and an LPF (Low Pass Filter) 40. The synchronization circuit 30 includes a distributor 31, a delay unit 32, a phase shifter 33, mixers 34 and 35, a determiner 36, LPFs 37 and 38, and a frequency converter 39.

Here, the mixer 21 generates and outputs a signal of the frequency f _out by down-converting the signal of the frequency f _if transmitted from the transmission device 10 with the signal of the frequency f _Lo4 supplied from the oscillator 24. . Oscillator 23 is composed of, for example, by a PLL circuit or the like, and outputs as a signal of a frequency _{f Lo3} by β times the frequency _{f ref} of the signal supplied from the LPF 40. Oscillator 24 is composed of, for example, by a PLL circuit or the like, by multiplying γ frequency _{f Lo3} of the signal supplied from the oscillator 23 to output as a signal of the frequency _{f Lo4.} The synchronization circuit 30 performs DPSK demodulation on the pilot signal having the frequency f _pl included in the down-converted signal output from the mixer 21, extracts the modulated signal, and supplies the modulated signal to the LPF 40. The LPF 40 attenuates and outputs the harmonic component of the modulated signal output from the synchronization circuit 30.

The distributor 31 of the synchronization circuit 30 distributes the signal output from the mixer 21 and supplies the signal to the delay unit 32, the mixer 34, and the mixer 35. The delay unit 32 delays the signal supplied from the distributor 31 by one symbol period (details will be described later) of the DPSK modulation signal and supplies the delayed signal to the mixer 34 and the phase shifter 33. The phase shifter 33 shifts the phase of the signal output from the delay device 32 by 90 ° and outputs it. The mixer 34 outputs an I (In-Phase) component obtained by multiplying the signal supplied from the distributor 31 by the signal delayed by one symbol period by the delay unit 32. The mixer 35 multiplies the signal supplied from the distributor 31 by the signal delayed by one symbol period by the delay unit 32 and shifted in phase by 90 ° by the phase shifter 33 (Qadrature). (Quadrature Phase)) component is output. The LPF 37 attenuates and outputs the high frequency component included in the I component output from the mixer 34. The LPF 38 attenuates and outputs a high frequency component included in the Q component output from the mixer 35. The determiner 36 performs bit determination based on the I component output from the LPF 37 and the Q component output from the LPF 38, and generates and outputs a modulated signal based on the determination result. The frequency converter 39 converts the frequency of the signal output from the determiner 36 into f _ref and outputs it. The LPF 40 attenuates the harmonic component included in the signal output from the frequency converter 39 and supplies it to the oscillator 23.

(B) Description of Operation of the Embodiment of the Present Invention Next, the operation of the embodiment of the present invention will be described. First, the operation of the transmission device 10 will be described. The oscillator 12 of the transmission device 10 generates a signal having a frequency f _{Lo1 and supplies} the signal to the oscillator 14, the frequency divider 16, and the clock generator 17. The frequency divider 16 _divides the frequency f _Lo1 signal supplied from the oscillator 12 to generate a modulated signal having the frequency f _ref , and supplies the modulated signal to the DPSK modulator 18. The clock generator 17 generates a clock signal by multiplying the frequency f _Lo1 of the signal supplied from the oscillator 12 and supplies the clock signal to the DPSK modulator 18. Oscillator 14 is supplied to the mixer 15 generates a signal of frequency _{f Lo2} by multiplying η frequency _{f Lo1} of the signal output from the oscillator 12.

  The DPSK modulator 18 performs DPSK modulation on the clock signal supplied from the clock generator 17 based on the modulated wave supplied from the frequency divider 16. FIG. 3 is a schematic diagram for explaining the operation principle of the DPSK modulator 18. FIG. 3A illustrates an example of a modulated wave, the horizontal axis indicates time, and the vertical axis indicates voltage. FIG. 3B illustrates an example of a signal obtained by modulation, the horizontal axis indicates time, and the vertical axis indicates voltage. In FIGS. 3A and 3B, the numbers on the horizontal axis indicate DPSK symbol intervals. In the example of FIG. 3A, the modulated wave is a signal that periodically repeats the “L” or “H” state. Specifically, it has an “L” state between symbol intervals 0 and 2, an “H” state between symbol intervals 2 and 3, and “L” or “ The state of “H” is periodically repeated. FIG. 3B shows an example of a modulated wave output from the DPSK modulator 18 when the modulated wave shown in FIG. 3A is input. Since the modulated wave is in the “L” state during the symbol sections 7 to 8 in FIG. 3A, in this case, the modulated wave output from the DPSK modulator 18 is shown in FIG. As shown in the figure, a signal having the same phase (phase difference of 0 °) as the signal in the immediately preceding symbol sections 6 to 7 is output. Further, since the modulated wave is in the “H” state during the symbol periods 2 to 3 in FIG. 3A, in this case, the modulated wave output from the DPSK modulator 18 is the same as that in FIG. ), A signal having a phase difference of 180 ° with respect to the signal in the immediately preceding symbol interval 1 or 2 is output. Thus, the DPSK modulator 18 outputs a signal having the same phase as the immediately preceding symbol interval when the modulated wave is “L”, and the immediately preceding symbol interval when the modulated wave is “H”. A signal having a phase difference of 180 ° is output.

The signal output from the DPSK modulator 18 is added as a pilot signal to the input signal by the combiner 11. The signal output from the coupler 11 is up-converted by the mixer 15 with the signal of the frequency f _Lo2 output from the oscillator 14 and output as a signal of the frequency f _if .

Next, the operation of the receiving device 20 will be described with reference to FIG. In the receiving device 20, the signal transmitted from the transmitting device 10 is down-converted in the mixer 21, and is output as a signal of the frequency f _out . More specifically, at the start of the operation of the receiving device 20, the oscillator 24 generates a predetermined signal and supplies it to the mixer 21. The mixer 21 down-converts the signal with the frequency f _if transmitted from the transmission device 10 with the signal with the frequency f _Lo4 supplied from the oscillator 24 and outputs a signal with the frequency f _out .

  The distributor 31 receives and distributes the signal output from the mixer 21 and supplies the signal to the delay device 32, the mixer 34, and the mixer 35. The delay unit 32 delays the signal output from the distributor 31 by one symbol period and supplies the delayed signal to the phase shifter 33 and the mixer 34. The phase shifter 33 delays the signal supplied from the delay unit 32 by 90 ° and outputs the delayed signal. As a result, the mixer 34 is supplied with a signal output from the distributor 31 and a signal delayed by one symbol period supplied from the delay unit 32. On the other hand, the mixer 35 is supplied with the signal output from the distributor 31 and the signal supplied from the delay unit 32 and delayed by one symbol period and further delayed by 90 ° by the phase shifter 33.

  For example, when the modulated wave is “L” and the signal output from the distributor 31 is sin ωt, the signal of one symbol interval output from the delay circuit 32 has the same phase, and thus becomes sin ωt. Also, the signal output from the phase shifter 33 is cos ωt because the phase is shifted by 90 °. Here, ω represents an angular frequency, and t represents time. In this case, the mixer 34 multiplies the signal sin ωt output from the distributor 31 by the signal sin ωt output from the delay unit 32, so that a signal of ½ cos 2ωt is output from the mixer 34. On the other hand, the mixer 35 multiplies the signal sin ωt output from the distributor 31 by the signal cos ωt output from the phase shifter 33, so that a signal of 1/2 sin2ωt is output from the mixer 35.

  Further, when the modulated wave is “H” and the signal output from the distributor 31 is sin ωt, the signal one symbol interval output from the delay circuit 32 has a phase difference of 180 °. −sin ωt, and the signal output from the phase shifter 33 is −cos ωt because the phase is delayed by 90 °. In this case, the mixer 34 multiplies the signal sin ωt output from the distributor 31 by the signal −sin ωt output from the delay unit 32, and thus a signal of −½ cos 2ωt is output from the mixer 34. On the other hand, since the mixer 35 multiplies the signal sin ωt output from the distributor 31 by the signal −cos ωt output from the phase shifter 33, the mixer 35 outputs a signal of −½ sin 2ωt.

  The LPF 37 attenuates the harmonic component included in the signal output from the mixer 34 and outputs the attenuated component to the determiner 36. Further, the LPF 38 attenuates the harmonic component included in the signal output from the mixer 35 and outputs the attenuated component to the determiner 36. The determiner 36 outputs a positive signal when the signals output from the LPF 37 and the LPF 38 are 1/2 cos 2ωt and 1/2 sin 2ωt, and the signals output from the LPF 37 and the LPF 38 are −1/2 cos 2ωt and −1 / In the case of 2sin2ωt, a negative signal is output. As a result, when the modulated wave is “L” (for example, in the case of the symbol sections 7 to 8 in FIG. 3A), the signals output from the LPF 37 and the LPF 38 are 1/2 cos 2ωt and 1/2 sin 2ωt. Therefore, a positive signal is output as shown in FIG. When the modulated wave is “H” (for example, in the case of symbol intervals 2 to 3 in FIG. 3A), the signals output from the LPF 37 and the LPF 38 are −1/2 cos 2ωt and −1/2 sin 2ωt. As a result, a negative signal is output as shown in FIG.

The frequency converter 39 adjusts the frequency so that the frequency of the signal output from the determiner 36 becomes f _ref , and then supplies it to the LPF 40. The LPF 40 attenuates the harmonic component included in the signal output from the determiner 36 and then supplies it to the oscillator 23.

Oscillator 23, by multiplying the frequency _{f ref} of the signals supplied β generates and outputs a signal of frequency _{f Lo3} by the LPF 40. Oscillator 24, a frequency _{f Lo3} of the signal supplied from the oscillator 23 generates a signal of frequency _{f Lo4} by multiplying γ outputs. Here, when the supply of the signal from the synchronization circuit 30 is started, the oscillator 24 stops outputting a signal having a preset frequency, and the frequency based on the signal of the frequency f _Lo3 supplied from the oscillator 23. f Generate and output _Lo4 signal. The mixer 21 down-converts the signal received from the transmission device 10 with the signal of the frequency f _Lo4 supplied from the oscillator 24, and generates and outputs a signal of the frequency f _out .

  By the way, in the configuration example shown in FIG. 2, the synchronization circuit 30 uses the DPSK modulation method, and therefore demodulates the modulated wave based on the signal one symbol interval before and the signal of the current symbol interval. Therefore, the modulated wave can be obtained without being affected by the transmission system. In the conventional example shown in FIG. 5, since the signal output from the mixer 21 is used as it is, it is necessary to set and adjust various parameters so that the phase characteristic and the amplitude characteristic in the feedback loop do not become unstable. . On the other hand, in the present embodiment, the modulated wave is demodulated from the difference in signal characteristics (phase characteristics in the example of FIG. 3) in the symbol period that is temporally changed, and down-conversion is performed based on the modulated wave. Therefore, the phase characteristic and amplitude characteristic in the feedback loop do not immediately affect the characteristic of the modulated wave to be demodulated, and therefore the phase characteristic and amplitude characteristic in the feedback loop can be designed flexibly.

  Further, in the receiving apparatus 20 of the present embodiment, the modulated wave signal is demodulated based on the difference in signal characteristics between adjacent symbol sections, so that signals other than the pilot signal to be demodulated (main signal) Can be demodulated as it is. This eliminates the need for a circuit configuration for attenuating signals other than the pilot signal, thereby simplifying the configuration of the apparatus.

(E) Description of Modified Embodiment The above embodiment is an example, and it is needless to say that the present invention is not limited to the case as described above. For example, the frequency of each part in the above embodiment is an example, and the present invention is not limited to the frequency described above, and it is also possible to select a frequency other than the illustrated frequency.

  In the above embodiment, DBPSK (Differential Binary Phase Shift Keying) has been described as an example. However, the present invention is not limited to such a modulation method, and for example, DQPSK (Differential Quaternary). Phase Shift Keying) may be used. Alternatively, in the above description, the modulation is performed by the DPSK method, but it is sufficient that the signal characteristics are different in adjacent symbol sections, and not only the phase but also the amplitude and frequency may be different, for example.

DESCRIPTION OF SYMBOLS 10 Transmitter 11 Coupler 12 Oscillator 14 Oscillator 15 Mixer 16 Divider 17 Clock generator 18 DPSK modulator 20 Receiver 21 Mixer 23 Oscillator 24 Oscillator 30 Synchronizer 31 Distributor 32 Delay 33 Phase shifter 34 Mixer 35 Mixer 36 Judger 37 LPF
38 LPF
39 Frequency converter 40 LPF

Claims (4)

In a transmission / reception system for transmitting a signal including a pilot signal from a transmission device to a reception device,
The transmitter is
Modulation means for modulating a signal of a predetermined frequency by a modulation method that represents information by a change in characteristics of signals in adjacent sections;
Adding means for adding the signal of the predetermined frequency modulated by the modulating means to the input signal as a pilot signal;
Up-conversion means for up-converting the frequency of the input signal to which the pilot signal is added based on the frequency of a reference signal generated from the same signal as the signal of the predetermined frequency;
Transmitting means for transmitting the signal up-converted by the up-conversion means,
The receiving device is:
Receiving means for receiving a signal transmitted by the transmitting means;
Down-converting means for down-converting the frequency of the signal received by the receiving means based on the frequency of the reference signal;
Demodulating means for inputting a signal down-converted by the down-converting means, demodulating the pilot signal from signal characteristic changes of adjacent sections of the inputted signal, and obtaining a signal of the predetermined frequency;
Generating means for generating the reference signal based on the predetermined frequency and supplying the reference signal to the down-converting means;
A transmission / reception system comprising:   The transmission / reception system according to claim 1, wherein the modulation unit and the demodulation unit perform modulation and demodulation based on DPSK (Differential Phase Shift Keying). In a transmitting apparatus that transmits a signal including a pilot signal to a receiving apparatus,
Modulation means for modulating a signal of a predetermined frequency by a modulation method that represents information by a change in characteristics of signals in adjacent sections;
Adding means for adding the signal of the predetermined frequency modulated by the modulating means to the input signal as a pilot signal;
Up-conversion means for up-converting the frequency of the input signal to which the pilot signal is added based on the frequency of a reference signal generated from the same signal as the signal of the predetermined frequency;
And a transmission means for transmitting the signal up-converted by the up-conversion means. In a receiving apparatus that receives a signal including a pilot signal transmitted from a transmitting apparatus,
A signal having a predetermined frequency is modulated by a modulation method that represents information by a change in signal characteristics of adjacent sections, and the obtained signal is added as a pilot signal to the input signal, and the frequency of the input signal to which the pilot signal is added Receiving means for receiving a signal transmitted from the transmitting device for up-converting and transmitting based on a frequency of a reference signal generated from the same signal as the signal of the predetermined frequency ;
Down-converting means for down-converting the frequency of the signal received by the receiving means based on the frequency of the reference signal;
Demodulating means for inputting a signal down-converted by the down-converting means, demodulating the pilot signal from signal characteristic changes of adjacent sections of the inputted signal, and obtaining a signal of the predetermined frequency;
Generating means for generating the reference signal based on the predetermined frequency and supplying the reference signal to the down-converting means;
A receiving apparatus comprising:

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