JP4485285B2 - Moving speed measuring method and moving speed measuring method - Google Patents

Description

  The present invention is for measuring the relative movement speed between a mobile station and a fixed station or between mobile stations using radio waves in the field of mobile communications.

To measure the relative movement speed between the partner station and the own station, (1) Receive radio waves transmitted from the partner station, and the number of fading fluctuations at that time (number of times the received signal crosses the average reception level) (2) Measure the carrier frequency difference between the partner station and the local station from the received signal, and move based on the "spread width" of the carrier frequency difference. A method for obtaining the speed (for example, refer to the same Patent Document 1) is considered.
JP-A-11-98071

  The method of measuring the number of fading fluctuations in (1) above differs in the way fading occurs depending on the propagation environment. For example, in a large city with many multipaths, a car can be used in a suburban area where there is a lot of traffic and where there are few multipaths. Where there is not much frequency, there is clearly a difference in the number of fluctuations. Therefore, the measurement of relative movement speed based on the number of fluctuations in fading involves a large measurement error.

On the other hand, the method of measuring the difference between the carrier frequency of the partner station and the own station from the received signal in (2) requires a highly stable crystal to measure how much the frequency has shifted due to the Doppler effect. There was a problem in feasibility. For example, in a mobile phone system having a carrier of about 1 to 2 GHz, when the terminal moves at a speed of 60 km / h, the maximum Doppler frequency is
f _d = carrier frequency × radio station relative speed / radio wave propagation speed = (1-2) × 10 ⁹ × 60 / (60 × 60 × 300000)
= 56-111Hz
It will be about.

However, 0.1 at high stability crystal of about × 10 ^-6, since with frequency error of approximately ^{1~2GHz × 0.1 × 10 -6 = 100~200Hz} , the or Doppler effect frequency of the crystal is shifted It was difficult to measure the Doppler frequency.

  Therefore, in this method, a method of obtaining the frequency shift due to the Doppler effect from the continuously changing frequency of the received frequency can be considered. However, in this case as well, the measurement error is different because the Doppler effect occurs depending on the radio wave propagation environment. As it became larger, it was difficult to accurately determine the moving speed. In particular, this method cannot measure the frequency by the Doppler effect because the spread width cannot be measured while the frequency is shifted in one direction when the radio wave comes from only one direction. .

  Further, the methods (1) and (2) both require a very long time before the influence of fading is removed and sufficient measurement accuracy is obtained.

  The present invention solves the problems of the conventional moving speed measuring method, and measures and measures the relative moving speed capable of accurately obtaining the value of the frequency shift due to the Doppler effect without being affected by the stability of the crystal. It is intended to provide.

  The present invention solves the above problems, and measures the relative movement speed between a mobile station and a fixed station or between mobile stations in a limited frequency band and with a monotonous waveform (for example, a sine wave). It is what makes it possible. Therefore, according to the present invention, when two waves having different frequencies are transmitted and the two waves are received at the other station, the two waves returned by the frequency shift are returned, and the two waves transmitted to the other station are returned. To generate two new waves that cancel each other so that they are not affected by the frequency uncertainty component added at the time of frequency shift at the other station. At this time, the frequency difference between the two new waves is due to the Doppler effect. The most important feature is to measure the frequency difference between the affected parts.

FIG. 1 is a diagram for explaining the outline of the present invention. In the present invention, the first oscillating means 101 of the radio station 1 oscillates a first wave of frequency f _1, the second oscillating means 102 frequency f ₂ second of (f ₂ ≠ f ₁₎ Waves are oscillated and each wave is transmitted from the transmission means 103 to the radio station 2.

The receiving means 201 of the radio station 2 receives the first wave and the second wave. Then, the frequency shift means 202 shifts the frequency of each wave by a predetermined frequency shift wave. By the frequency processing by the frequency shift means 202, a third wave having the frequency f ₃ is generated from the first wave, and a _fourth wave having the frequency f ₄ (f ₄ ≠ f ₃ ) is generated from the second wave. Is done. The transmission unit 203 transmits the generated third wave and fourth wave to the radio station 1.

The frequency shift means 202 shifts the waves having the frequencies f ₁ and f _{2 because} the wave transmitted from the radio station 2 to the radio station 1 by the transmission means 203 is received by the reception means 201 of the radio station 2 and the radio station 1 This is so as not to be confused with the wave from.

  When the receiving means 104 of the wireless station 1 receives the third wave and the fourth wave, the frequency shifting means 105 is different between the first wave, the second wave, the third wave, and the fourth wave. By shifting the frequency using two sets of two waves, a fifth wave whose frequency difference is determined by the Doppler effect due to the relative moving speed between the first radio station and the second radio station; A sixth wave is generated. Any of the following may be used as a method of generating the fifth wave and the sixth wave.

  (1) The fifth wave is generated by the frequency shift means for shifting the frequency by inputting the first wave and the second wave, and the frequency is shifted by inputting the third wave and the fourth wave. The sixth wave is generated by the frequency shift means.

  (2) The fifth wave is generated by the frequency shift means for shifting the frequency by inputting the first wave and the third wave, and the frequency is shifted by inputting the second wave and the fourth wave. The sixth wave is generated by the frequency shift means.

  (3) The fifth wave is generated by the frequency shift means for shifting the frequency by inputting the first wave and the fourth wave, and the frequency is shifted by inputting the second wave and the third wave. The sixth wave is generated by the frequency shift means.

  Even if any one of the above methods (1) to (3) is used, two new offsets are made so as not to be affected by the frequency indeterminate component added at the time of frequency shift by the frequency shift means 202 in the radio station 2. Can generate waves. In addition, at this time, it is possible to measure the frequency difference between the fifth wave and the sixth wave so that the frequency difference is only an influence due to the Doppler effect.

  The measuring means 106 obtains the relative moving speed between the radio station 1 and the radio station 2 based on the generated frequency difference between the fifth wave and the sixth wave.

  Since the present invention is a method for directly obtaining the frequency shift due to the Doppler effect regardless of the stability of the carrier frequency of the local station and the counterpart station, it is a wave that arrives continuously only from one direction. However, accurate measurement is possible in a short time. In particular, even if the carrier frequency is about 1 to 2 GHz or higher and the frequency value shifted by the Doppler effect and the frequency value shifted because the stability of the carrier frequency itself is insufficient, The invention can measure the frequency shift due to the influence of the Doppler effect without any problem.

  Since the present invention uses a method for measuring the Doppler effect of a monotonic periodic signal, it is possible to directly measure the relative moving speed between a mobile station and a fixed station or a mobile station by radio waves without widening the frequency band. There is an effect that it is possible.

[First Embodiment]
The first embodiment of the present invention is a method for measuring the relative movement speed between a first radio station and a second radio station, and the first radio station and the second radio station are respectively Means described below are provided.

The first radio station
First oscillating means for oscillating a first wave;
A second oscillating means for oscillating a second wave;
First transmission means for transmitting the first wave as a radio wave;
Second transmitting means for transmitting the second wave as a radio wave,
The first wave and the second wave are transmitted to the second radio station.

The second radio station
First receiving means for receiving the transmitted first wave;
Second receiving means for receiving the transmitted second wave;
A third oscillation means for oscillating a frequency shift wave;
A first frequency shift means for inputting a first wave received by the first receiving means and a wave for frequency shift, shifting the frequency and outputting a third wave;
A second frequency shift means for inputting a second wave and a frequency shift wave received by the second reception means, shifting the frequency and outputting a fourth wave;
A third transmission means for transmitting a third wave;
A fourth transmission means for transmitting the fourth wave,
The third wave and the fourth wave are transmitted to the first radio station.

Furthermore, the first radio station
Third receiving means for receiving a third wave;
A fourth receiving means for receiving a fourth wave;
Obtained from the first wave obtained from the first oscillating means, the second wave obtained from the second oscillating means, the third wave obtained from the third receiving means, and the fourth receiving means. Multi-frequency shift means for inputting the received fourth wave and shifting the respective frequencies;
Doppler frequency shift measuring means for measuring a frequency shift due to the Doppler effect caused by relative movement between the first radio station and the second radio station according to the processing result of the multi-frequency shift means;
A conversion means for converting the measured Doppler frequency shift into a relative movement speed;
The relative moving speed between the first radio station and the second radio station is measured.

[Second Embodiment]
The second embodiment of the present invention is the same as the first embodiment described above.
The multi-frequency shift means in the first radio station is:
Third frequency shifting means for inputting the third wave received by the third receiving means and the fourth wave received by the fourth receiving means and shifting the frequency;
A fourth frequency shift means for inputting the first wave obtained from the first oscillation means and the second wave obtained from the second oscillation means and shifting the frequency;
The Doppler frequency shift measuring means is:
Frequency shift extraction means for taking out the Doppler frequency shift by inputting the output of the third frequency shift means and the output of the fourth frequency shift means is provided.

[Third Embodiment]
The third embodiment of the present invention is the same as the first embodiment described above.
The multi-frequency shift means in the first radio station is:
A fifth frequency shift means for shifting the frequency by inputting the third wave received by the third receiving means and the first wave obtained from the first oscillation means;
A fourth frequency shift means for inputting the fourth wave received by the fourth reception means and the second wave obtained from the second oscillation means and shifting the frequency;
The Doppler frequency shift measuring means is:
Frequency shift extracting means for taking out the Doppler frequency shift by inputting the outputs of the fifth frequency shift means and the sixth frequency shift means is provided.

[Fourth Embodiment]
The fourth embodiment of the present invention is the same as the first embodiment described above.
The multi-frequency shift means in the first radio station is:
A seventh frequency shift means for inputting the third wave received by the third receiving means and the second wave obtained from the second oscillating means and shifting the frequency;
An eighth frequency shift means for inputting the fourth wave received by the fourth reception means and the first wave obtained from the first oscillation means and shifting the frequency;
The Doppler frequency shift measuring means is:
Frequency shift extracting means for taking out the Doppler frequency shift by inputting the outputs of the seventh frequency shift means and the eighth frequency shift means is provided.

[Fifth Embodiment]
The fifth embodiment of the present invention is the same as the first to fourth embodiments described above.
A first common transmission unit that uses the first transmission unit and the second transmission unit of the first wireless station in common is provided, and the first common wave and the second wave are combined to form a first common Transmit by transmission means.

[Sixth Embodiment]
The sixth embodiment of the present invention is the same as the first to fifth embodiments described above.
First common receiving means for commonly using the first receiving means and the second receiving means of the second wireless station is provided, and the first wave and the second wave transmitted from the first wireless station are provided. Are received by the first common receiving means, and their outputs are used separately.

[Seventh Embodiment]
The seventh embodiment of the present invention is the same as the first to sixth embodiments described above.
A second common transmission unit that uses the third transmission unit and the fourth transmission unit of the second radio station in common is provided, and the third wave and the fourth wave are combined to form a second common Transmit by transmission means.

[Eighth Embodiment]
The eighth embodiment of the present invention is the same as the first to seventh embodiments described above.
A second common receiving means for commonly using the third receiving means and the fourth receiving means of the first radio station is provided, and the third wave and the fourth wave are received by the second common receiving means. The output is used separately.

  Hereinafter, the relative movement speed of the radio station 1 and the radio station 2 is measured by measuring the Doppler effect of the radio wave for the radio station 1 and the radio station 2 moving with each other with reference to the drawings. Examples will be described.

FIG. 2 is a diagram showing Example 1 of the present invention. It is assumed that the radio station 1 and the radio station 2 are moving at the relative movement speed Vd. The radio station 1 includes an oscillator 3 that oscillates a wave having a frequency f ₁ and an oscillator 4 that oscillates a wave having a frequency f ₂ . The output of the oscillator 3 is transmitted from the first transmitter including the amplifier 5 and the antenna 6, and the output of the oscillator 4 is transmitted from the second transmitter including the amplifier 7 and the antenna 8. The here,
The frequency of the radio wave transmitted from the antenna 6 is f ₁
The frequency of the radio wave transmitted from the antenna 8 is f ₂
It is.

In the radio station 2, the wave transmitted from the antenna 6 is received by the first receiver including the antenna 9, the receiving amplifier 10, and the band pass filter 11, while the wave transmitted from the antenna 8 is the antenna 12, The signal is received by the second receiver comprising the receiving amplifier 13 and the band pass filter 14. At this time, the wave received by each antenna is shifted under the influence of the Doppler effect,
・ The frequency of the radio wave received by the antenna 9 is f ₁ + f _d1 ,
The frequency of the radio wave received by the antenna 12 is f ₂ + f _d2 ,
It is.

Here, f _d1 and f _d2 are the values of the frequency shifted by the Doppler effect, and the propagation speed of the radio wave is the speed of light c.
f _d1 = Vd × f ₁ / c (1)
f _d2 = Vd × f ₂ / c (2)
It is.

In the embodiment of the present invention, a frequency shift wave (frequency Δf) is oscillated by the oscillator 15, and the frequency of the received waves is shifted by the frequency shift means 16 and 19. Here, in order to simplify the description, a case where f ₁ > f ₂ >Δf> 0 is described first.

The frequency shift means 16 includes a mixer 17 and a low-pass filter 18 and shifts the output frequency of the band-pass filter 11 in a subtracting direction (MIX-DOWN: the same applies hereinafter). That is, the frequency of the output of the frequency shift means 16 is
f ₃ = f ₁ + f _d1 −Δf (3)
It is.

The frequency shift means 19 comprises a mixer 20 and a low-pass filter 21 and shifts the frequency of the output of the band-pass filter 14 in the subtracting direction. That is, the frequency of the output of the frequency shift means 19 is
f ₄ = f ₂ + f _d2 −Δf (4)
It is.

  The output of the frequency shift means 16 is transmitted by a third transmitter comprising an amplifier 22 and an antenna 23, while the output of the frequency shift means 19 is transmitted by a fourth transmitter comprising an amplifier 24 and an antenna 25.

here,
The frequency of the radio wave transmitted from the antenna 23 is f ₃ = f ₁ + f _d1 −Δf (5)
The frequency of the radio wave transmitted from the antenna 25 is f ₄ = f ₂ + f _d2 −Δf (6)
It is.

  In the radio station 1, the wave transmitted from the antenna 23 is received by a third receiver including the antenna 26, the receiving amplifier 27, and the band pass filter 28, while the wave transmitted from the antenna 25 is transmitted to the antenna 29. , Reception amplifier 30 and band-pass filter 31.

At this time, the wave received by each antenna is shifted under the influence of the Doppler effect,
The frequency of the radio wave received by the antenna 26 is f ₃ + f _d3 ,
・ The frequency of the radio wave received by the antenna 29 is f ₄ + f _d4 ,
It is.

Here, f _d3 and f _d4 are values of the frequency shifted by the Doppler effect,
f _d3 = Vd × f ₃ / c = (f ₁ + f _d1 −Δf) Vd / c (7)
f _d4 = Vd × f ₄ / c = (f ₂ + f _d2 −Δf) Vd / c (8)
It is.

In the radio station 1, the wave of the frequency f ₁ oscillated by the oscillator 3, the wave of the frequency f ₂ oscillated by the oscillator 4, the wave of the frequency f ₃ + f _d3 of the output of the band pass filter 28, and the frequency of the output of the band pass filter 31. The wave of f ₄ + f _d4 is input to the multi-frequency shift means 32, and the relative movement speed between the radio station 1 and the radio station 2 is obtained using the result.

  In the case of the first embodiment shown in FIG. 2, the multi-frequency shift means 32 includes two frequency shift means 33 and 34. The frequency shift means 33 includes a mixer 35 and a low-pass filter 36, and shifts the output frequency of the band-pass filter 28 and the output frequency of the band-pass filter 31 in the subtracting direction.

As a result, the frequency of the output of the frequency shift means 33 is
f ₅ = (f ₃ + f _d3 ) − (f ₄ + f _d4 )
= (F ₁ −f ₂ ) + (f ₁ −f ₂ ) (2 + Vd / c) Vd / c (9)
It becomes.

The frequency shift means 34 comprises a mixer 37 and a low-pass filter 38, and has a frequency wave that is the difference between the frequency f ₁ wave and the frequency f ₂ wave,
f ₆ = f ₁ −f ₂ (10)
Get.

Frequency shift means 39 and speed display means 42 are used as means for measuring the relative movement speed between radio stations. First, comparing Equation (9) with Equation (10), it can be seen that if the difference between the frequency f ₅ and the frequency f ₆ is taken, only the influence due to the Doppler effect remains. Therefore, in the first embodiment, the output of the frequency shift means 33 and the output of the frequency shift means 34 are input to the frequency shift means 39 in order to extract this influence.

The frequency shift means 39 is composed of a mixer 40 and a low-pass filter 41, and has a frequency wave that is the difference between the frequency f ₅ wave and the frequency f ₆ wave,
f ₇ = f ₅ −f ₆
= (F ₁ −f ₂ ) (2 + Vd / c) Vd / c (11)
Get. Here, as the Doppler frequency shift extraction means, the frequency difference between f ₅ and f ₆ is obtained by the frequency shift means 39. For example, the frequency of f _{5 and} the frequency of f ₆ are obtained by using a frequency counter, for example. Thus, the frequency of these differences may be obtained by a calculation means. The same applies to other embodiments.

The speed display means 42 obtains the frequency of the output of the frequency shift means 39, calculates f ₇ × c / {2 (f ₁ −f ₂ )}, and displays it to obtain the next measurement result.
Measurement result of relative movement speed = Vd {1 + Vd / (2c)} ≈Vd (12)
In the first embodiment of the present invention shown in FIG. 2, the polarity of the frequency shift means 16, 19, 33, and 34 is shifted in the direction of subtraction (MIX-DOWN). Several other combinations of shifting polarity are possible.

Table 1 shows an example of the relationship between the frequency of the output of the frequency shift means 39 and the polarity of each frequency shift means for the case of f ₁ > f ₂ >Δf> 0. “Addition” means shifting in a direction in which the absolute value of the frequency increases (MIX-UP), and subtraction means shifting in a direction in which the absolute value of the frequency decreases (MIX-DOWN).

Table 2 shows an example of the relationship between the frequency of the output of the frequency shift means 39 and the polarity of each frequency shift means in the case of f ₁ >Δf> f ₂ > 0.

Table 3 shows an example of the relationship between the output frequency of the frequency shift means 39 and the polarity of each frequency shift means when Δf> f ₁ > f ₂ > 0.

From Tables 1 to 3, the frequency of f ₇ is (f ₁ + f ₂ ) (2 + Vd / c) Vd / c and (f ₁ −f ₂ ) (2 + Vd / c) Vd / c. There are cases. To determine the relative moving velocity, in the former case, multiplied by _{c / {2 (f 1 +} f 2)} to f _7, in the latter case, applying a _{c / {2 (f 1 -f} 2)} to f ₇ . In any case, if Vd / c is regarded as a sufficiently small value and ignored, the calculation result is practically equal to Vd.

  FIG. 3 is a diagram showing Embodiment 2 of the present invention. The difference between FIG. 2 and FIG. 3 is that, in the multi-frequency shift means 32 of FIG. 2, the wave obtained by mixing the first wave and the second wave (transmission waves), the third wave and the fourth wave The influence of the Doppler effect was obtained by comparing the waves obtained by mixing the waves (between the received waves). In FIG. 3, the first and third waves (transmitted wave and received wave) are obtained in the multi-frequency shift means 43. ) And a wave obtained by mixing the second wave and the fourth wave (the other transmission wave and reception wave) are measured to measure the influence of the Doppler effect.

Also in the radio station 1 of FIG. 3, the frequencies of the waves transmitted from the antenna 6 and the antenna 8 are f ₁ and f ₂ , respectively, as in the case of FIG.

In the radio station 2 of FIG. 3, each wave is received under the influence of the Doppler effect, and as in the case of FIG.
・ The frequency of the radio wave received by the antenna 9 is f ₁ + f _d1 ,
The frequency of the radio wave received by the antenna 12 is f ₂ + f _d2 ,
It is. f _d1 and f _d2 are given by Equation (1) and Equation (2), respectively.

Also in this case, in order to simplify the description, a case where f ₁ > f ₂ >Δf> 0 will be described first. Also in the second embodiment of the present invention shown in FIG. 3, the radio station 2 uses the same frequency as in the first embodiment of FIG. 2 to subtract the two frequencies f ₁ + f _d1 and f ₂ + f _d2 by Δf. Shift to
The frequency of the radio wave transmitted from the antenna 23 is f ₃ = f ₁ + f _d1 −Δf (13)
The frequency of the radio wave transmitted from the antenna 25 is f ₄ = f ₂ + f _d2 −Δf (14)
It is.

At this time, the waves received by the respective antennas 26 and 29 of the radio station 1 are shifted under the influence of the Doppler effect,
The frequency of the radio wave received by the antenna 26 is f ₃ + f _d3 ,
・ The frequency of the radio wave received by the antenna 29 is f ₄ + f _d4 ,
It is.

Here, f _d3 and f _d4 are values of the frequency shifted by the Doppler effect,
f _d3 = Vd × f ₃ / c = (f ₁ + f _d1 −Δf) Vd / c (15)
f _d4 = Vd × f ₄ / c = (f ₂ + f _d2 −Δf) Vd / c (16)
It is.

In the radio station 1, the wave of the frequency f ₁ oscillated by the oscillator 3, the wave of the frequency f ₂ oscillated by the oscillator 4, the wave of the frequency f ₃ + f _d3 of the output of the band pass filter 28, and the frequency of the output of the band pass filter 31. The wave of f ₄ + f _d4 is input to the multi-frequency shift means 43, and the relative movement speed between the radio station 1 and the radio station 2 is obtained using the result.

In the case of the second embodiment shown in FIG. 3, the multi-frequency shift means 43 includes two frequency shift means 44 and 45. The frequency shift means 44 comprises a mixer 46 and a low-pass filter 47, and shifts the frequency of the output of the band-pass filter 28 and the frequency f ₁ of the output of the oscillator 3 in the subtracting direction. As a result, the frequency of the output of the frequency shift means 44 is
f ₈ = f ₁ − (f ₃ + f _d3 ) (17)
It becomes.

The frequency shift means 45 comprises a mixer 48 and a low-pass filter 49, and shifts the frequency of the output of the band-pass filter 31 and the frequency f ₂ of the output of the oscillator 4 in the subtracting direction. As a result, the frequency of the output of the frequency shift means 45 is
f ₉ = f ₂ − (f ₄ + f _d4 ) (18)
It becomes.

In the second embodiment, frequency shift means 39 and speed display means 42 are used as means for measuring the relative movement speed between radio stations. The frequency shift means 39 inputs the output of the frequency shift means 44 and the output of the frequency shift means 45, obtains the difference between f ₈ and f ₉ and extracts the influence of the Doppler effect.

f ₁₀ = f ₉ −f ₈
= (F ₁ −f ₂ ) (2 + Vd / c) Vd / c (19)
Get.

Thereafter, as in the case of the first embodiment, the speed display means 42 obtains the frequency of the output of the frequency shift means 39, calculates f ₁₀ × c / {2 (f ₁ −f ₂ )}, and displays it. By doing so, the following measurement results are obtained.
Measurement result of relative movement speed = Vd {1 + Vd / (2c)} ≈Vd (20)
In the second embodiment of the present invention shown in FIG. 3, the polarities shifted with respect to the frequencies of the frequency shift means 16, 19, 44, 45 are all shifted in the subtracting direction (MIX-DOWN). Several other combinations of shifting polarity are possible.

Table 4 shows an example of the relationship between the output frequency of the frequency shift means 39 and the polarity of each frequency shift means in the case of f ₁ > f ₂ >Δf> 0. “Addition” means shifting in a direction in which the absolute value of the frequency increases (MIX-UP), and subtraction means shifting in a direction in which the absolute value of the frequency decreases (MIX-DOWN).

Table 5 shows an example of the relationship between the output frequency of the frequency shift means 39 and the polarity of each frequency shift means for the case of f ₁ >Δf> f ₂ > 0.

Table 6 shows an example of the relationship between the output frequency of the frequency shift means 39 and the polarity of each frequency shift means when Δf> f ₁ > f ₂ > 0.

As can be seen from Tables 4 to 6, as in Example 1, the frequency of f ₁₀ is (f ₁ + f ₂ ) (2 + Vd / c) Vd / c, and (f ₁ −f ₂ ) (2 + Vd / c) Vd / c. To determine the relative moving velocity, in the former case, multiplied by _{c / {2 (f 1 +} f 2)} to f _10, in the latter case, applying a _{c / {2 (f 1 -f} 2)} to f ₁₀ . In any case, if Vd / c is regarded as a sufficiently small value and ignored, the calculation result is practically equal to Vd.

FIG. 4 is a diagram showing Embodiment 3 of the present invention. Similarly to the case of FIG. 3, the frequencies of the outputs of the bandpass filters 11 and 14 of the radio station 2 are f ₁ + f _d1 and f ₂ + f _d2 (f _d1 and f _d2 are the expressions (1) and (2), respectively. In the frequency shift means 50 and 53, the two frequencies f ₁ + f _d1 and f ₂ + f _d2 are shifted in the direction of adding Δf.

The frequency shift means 50 is composed of a mixer 51 and a high-pass filter 52, and shifts in the direction of adding Δf to the output frequency of the band-pass filter 11. The frequency shift means 53 includes a mixer 54 and a high-pass filter 55, and shifts the output frequency of the band-pass filter 14 and Δf in the adding direction. as a result,
The frequency of the radio wave transmitted from the antenna 23 is f ₃ = f ₁ + f _d1 + Δf (21)
The frequency of the radio wave transmitted from the antenna 25 is f ₄ = f ₂ + f _d2 + Δf (22)
It is.

At this time, the waves received by the respective antennas 26 and 29 of the radio station 1 are shifted under the influence of the Doppler effect,
The frequency of the radio wave received by the antenna 26 is f ₃ + f _d3 ,
・ The frequency of the radio wave received by the antenna 29 is f ₄ + f _d4 ,
It is.

Here, f _d3 and f _d4 are values of the frequency shifted by the Doppler effect,
f _d3 = Vd × f ₃ / c = (f ₁ + f _d1 + Δf) Vd / c (23)
f _d4 = Vd × f ₄ / c = (f ₂ + f _d2 + Δf) Vd / c (24)
It is.

In the radio station 1, the wave of the frequency f ₁ oscillated by the oscillator 3, the wave of the frequency f ₂ oscillated by the oscillator 4, the wave of the frequency f ₃ + f _d3 of the output of the band pass filter 28, and the frequency of the output of the band pass filter 31. The wave of f ₄ + f _d4 is input to the multi-frequency shift means 56, and the relative movement speed between the radio station 1 and the radio station 2 is obtained using the result.

In the third embodiment shown in FIG. 4, the multi-frequency shift means 56 includes two frequency shift means 57 and 58. Frequency shifting means 57, a mixer 59 made of a high-pass filter 60, the frequency f ₂ of the output frequency and the oscillator 4 of the output of the band pass filter 28 is shifted in the direction of addition. As a result, the frequency of the output of the frequency shift means 57 is
f ₁₁ = f ₂ + (f ₃ + f _d3 ) (25)
It becomes.

The frequency shift means 58 includes a mixer 61 and a high-pass filter 62, and shifts the output frequency of the band-pass filter 31 and the frequency f ₁ of the output of the oscillator 3 in the adding direction. As a result, the frequency of the output of the frequency shift means 58 is
f ₁₂ = f ₁ + (f ₄ + f _d4 ) (26)
It becomes.

Also in the third embodiment, frequency shift means 39 and speed display means 42 are used as means for measuring the relative movement speed between radio stations. The frequency shifting means 39 inputs the outputs of the frequency shifting means 58 of the frequency shifting means 57, and determines the difference between f ₁₁ and f _12, is taken out the influence component of the Doppler effect. The wave of the frequency difference between the wave of frequency f _{11 and} the wave of frequency f ₁₂ is
f ₁₃ = f ₁₁ −f ₁₂
= (F ₁ −f ₂ ) (2 + Vd / c) Vd / c (27)
Get.

Thereafter, as in the case of the second embodiment, the speed display means 42 obtains the frequency of the output of the frequency shift means 39, calculates f ₁₃ × c / {2 (f ₁ −f ₂ )}, and displays it. By doing so, the following measurement results are obtained.
Measurement result of relative movement speed = Vd {1 + Vd / (2c)} ≈Vd (20)
In the third embodiment of the present invention shown in FIG. 4, the polarities of the frequency shift means 50, 53, 57, and 58 are shifted in the adding direction (MIX-UP). Several other combinations of shifting polarity are possible.

Table 7 shows an example of the relationship between the output frequency of the frequency shift means 39 and the polarity of each frequency shift means in the case of f ₁ > f ₂ >Δf> 0. “Addition” means shifting in a direction in which the absolute value of the frequency increases (MIX-UP), and subtraction means shifting in a direction in which the absolute value of the frequency decreases (MIX-DOWN).

Table 8 shows an example of the relationship between the output frequency of the frequency shift means 39 and the polarity of each frequency shift means when f ₁ >Δf> f ₂ > 0.

Table 9 shows an example of the relationship between the frequency of the output of the frequency shift means 39 and the polarity of each frequency shift means when Δf> f ₁ > f ₂ > 0.

As can be seen from Tables 7 to 9, the frequency of f ₁₃ is (f ₁ + f ₂ ) (2 + Vd / c) Vd / c, and (f ₁ −f ₂ ), as in Examples 1 and _2. ) (2 + Vd / c) Vd / c. To determine the relative moving velocity, in the former case, multiplied by _{c / {2 (f 1 +} f 2)} to f _13, in the latter case, applying a _{c / {2 (f 1 -f} 2)} to f ₁₃ . In any case, if Vd / c is regarded as a sufficiently small value and ignored, the calculation result is practically equal to Vd.

  FIG. 5 shows a fourth embodiment of the present invention. In this embodiment, the amplifier 5, the antenna 6, the amplifier 7 and the antenna 8 corresponding to the first transmitter and the second transmitter in FIG. 2 are composed of the adder 63, the amplifier 64 and the antenna 65 in FIG. The antenna 9, the reception amplifier 10, the bandpass filter 11 and the antenna 12, the reception amplifier 13, the bandpass filter corresponding to the first receiver and the second receiver of FIG. 14 is constituted by a first common receiving means comprising an antenna 66, a receiving amplifier 67, and bandpass filters 11 and 14.

  Further, an amplifier 22, an antenna 23, an amplifier 24, and an antenna 25 corresponding to the third transmitter and the fourth transmitter in FIG. 2 are added to the second adder 68, the amplifier 69, and the antenna 70 in FIG. The antenna 26, the reception amplifier 27, the band-pass filter 28 and the antenna 29, the reception amplifier 30, and the band-pass filter 31 corresponding to the third receiver and the fourth receiver in FIG. , And a second common receiving means comprising the antenna 71, the receiving amplifier 72, and the band-pass filters 28 and 31 shown in FIG.

In Examples 1 to 3 of the present invention, respectively when the frequency f ₁ and f ₂ are very far, although an example using a dedicated amplifier for each frequency, the frequency of each other f ₁ and f ₂ Is close, the amplifier can be used in common and it is economical. In addition, when amplifiers are shared, there is an advantage that variations in delay time due to amplifiers are reduced compared to a case where they are configured separately.

It is a figure explaining the outline | summary of this invention. It is a figure which shows Example 1 of this invention. It is a figure which shows Example 2 of this invention. It is a figure which shows Example 3 of this invention. It is a figure which shows Example 4 of this invention.

Explanation of symbols

1, 2, radio station 3, 4, 15 oscillator 5, 7, 22, 24, 64, 69 amplifier 6, 8, 9, 12, 23, 25, 26, 29, 65, 66, 70, 71 antenna 10, 13 27, 30, 67, 72 Receiving amplifier 11, 14, 28, 31 Band pass filter 16, 19, 33, 34, 39, 44, 45, 50, 53, 57, 58, 105,
202 Frequency shift means 17, 20, 35, 37, 40, 46, 48, 51, 54, 59, 61 Mixer 18, 21, 36, 38, 41, 47, 49 Low-pass filter 52, 55, 60, 62 High-pass filter 32, 43, 56 Multi-frequency shift means 42 Speed display means 63, 68 Adder 101 First oscillating means 102 Second oscillating means 103, 203 Transmitting means 104, 201 Receiving means 106 Measuring means

Claims (2)

A method for measuring a relative movement speed between a first radio station and a second radio station, comprising:
Transmitting a first wave and a second wave having different frequencies from the first radio station as radio waves;
The second radio station receives the first wave and the second wave transmitted from the first radio station , and mixes the received first wave with a predetermined frequency shift wave. Thereby shifting the frequency to generate a third wave, mixing the received second wave and the predetermined frequency shifting wave to shift the frequency to generate a fourth wave, Send the third and fourth waves as radio waves,
The first radio station receives the third wave and the fourth wave transmitted from the second radio station,
(A) A frequency is shifted by mixing the transmitted first wave and the transmitted second wave to generate a fifth wave, and the received third wave and the received fourth wave To generate a sixth wave with a frequency shift by mixing with
(B) A frequency is shifted by mixing the transmitted first wave and the received third wave to generate a fifth wave, and the transmitted second wave and the received fourth wave To generate a sixth wave with a frequency shift by mixing with
(C) A frequency is shifted by mixing the transmitted first wave and the received fourth wave to generate a fifth wave, and the transmitted second wave and the received third wave To generate a sixth wave by shifting the frequency by mixing
The fifth on the basis of the frequency difference of the wave and the sixth wave of the moving speed measuring method characterized by measuring the relative velocity between the first radio station and the second radio station. A method for measuring a relative moving speed between a first radio station and a second radio station,
The first radio station is:
Transmitting means for transmitting the first wave and the second wave having different frequencies as radio waves;
Receiving means for receiving a third wave and a fourth wave transmitted from the second radio station;
(A) A frequency is shifted by mixing the transmitted first wave and the transmitted second wave to generate a fifth wave, and the received third wave and the received fourth wave The frequency is shifted by mixing the first wave and the sixth wave to generate the sixth wave, or (b) the frequency is mixed by mixing the transmitted first wave and the received third wave. Shift to generate a fifth wave and mix the transmitted second wave and the received fourth wave to shift the frequency to generate a sixth wave, or (c ) A frequency is shifted by mixing the transmitted first wave and the received fourth wave to generate a fifth wave, and the transmitted second wave and the received third wave The frequency is shifted by mixing the And the frequency shift means for generating,
The fifth on the basis of the frequency difference of the wave and the sixth wave of, and a measuring means for measuring the radio wave of the relative movement speed between the first radio station and the second radio station,
The second radio station is
Receiving means for receiving the first wave and the second wave transmitted from the first radio station;
The received first wave and a predetermined frequency shift wave are mixed to generate a third wave by shifting the frequency, and the received second wave and the predetermined frequency shift wave A frequency shift means for generating a fourth wave by shifting the frequency by mixing
Moving speed measuring method characterized by comprising a transmitting means for transmitting the third wave and the fourth wave of the radio wave.

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