JPH114184A - Separation device and method for waveform signal superimposed on sine wave signal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device/method which can separate the superimposed waveform information signal from the synthetic signal obtained by superimposing an optional waveform information signal on a sine wave signal without causing any distortion of waveform on a time base. SOLUTION: A sine wave signal is extracted from the sine wave signal on which a waveform signal is superimposed via an LPF 12, and the phase of the extracted sine wave signal is shifted by a differentiator 16. The sine wave signal extracted by the LPF 12 is added to the phase shifted sine wave signal by a phase converter 20 to generate a sine wave signal on which the waveform signal is not superimposed yet. The generated sine wave signal is subtracted from the sine wave signal on which the waveform signal is superimposed by 4 subtracter 30. Thus, the relevant waveform signal is extracted. As a sine wave signal having no phase shift to the original sine wave signal is generated and a waveform signal is extracted, the waveform signal can be extracted with no distortion caused on a time base. Therefore, this device/ method can be suitably used when the transmitted signal is reproduced in a spread spectrum communication system.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a separating apparatus and a separating method for separating a waveform signal (information signal) superimposed on a sine wave signal (carrier signal).

[0002]

2. Description of the Related Art In a power line carrier or the like, a sine wave power signal is used as a carrier wave, and an information signal is superimposed on the power signal and transmitted. On the receiving side, the power signal is separated using an information signal filter or the like superimposed on the power signal. Here, when the information signal is separated from the power signal, the phase of the separated information signal is displaced due to the characteristics of the filter. However, when the information signal is an analog voice or the like, there is essentially no problem.

[0003]

Here, when a digital signal is transmitted by the power line carrier, the phase of the digital signal is displaced on the receiving side, and the waveform is distorted on the time axis. When a pulse signal is transmitted by the PCM method, even if the waveform is distorted on the time axis, the pulse signal can be newly generated on the receiving side to cope with the distortion.

However, when a signal is multiplexed by the spread spectrum method, a new pulse signal cannot be generated on the receiving side unlike the PCM method. The distortion of the waveform on the time axis at the time of reception is a major problem of the spread spectrum system.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and an object of the present invention is to obtain a composite signal obtained by superimposing an arbitrary waveform information signal on a sine wave signal.
An object of the present invention is to provide an apparatus and a method capable of separating a superimposed waveform information signal without distorting a waveform on a time axis.

[0006]

According to a first aspect of the present invention, there is provided a filter for extracting a sine wave signal from a sine wave signal on which a waveform signal is superimposed, and a sine wave signal extracted by the filter. Phase shifting means for giving a phase shift to the sine wave signal extracted by the filter, and a sine wave signal given a phase shift by the phase shifting means to add a sine wave signal before the waveform signal is superimposed. Phase conversion means for generating a sine wave signal, and subtraction means for extracting the waveform signal by subtracting the sine wave signal generated by the phase conversion means from the sine wave signal on which the waveform signal is superimposed. It is a technical feature to provide.

Further, the invention of claim 2 is characterized in that, in claim 1, the phase displacement means comprises a differentiating circuit or an integrating circuit.

According to a second aspect of the present invention, in order to achieve the above object, a step of extracting a sine wave signal from a sine wave signal on which a waveform signal is superimposed by a filter, and adding a phase to the sine wave signal extracted by the filter. Adding a sine wave signal extracted by the filter and a sine wave signal given a phase shift by the step to generate a sine wave signal before the waveform signal is superimposed. And a step of extracting the waveform signal by subtracting the sine wave signal generated in the step from the sine wave signal on which the waveform signal is superimposed.

According to the first or second aspect of the present invention, a sine wave signal is extracted from the sine wave signal on which the waveform signal is superimposed by a filter, and a phase shift is given to the extracted sine wave signal.
The sine wave signal extracted by the filter and the sine wave signal having a phase shift are added to generate a sine wave signal before the waveform signal is superimposed. Then, by subtracting the generated sine wave signal from the sine wave signal on which the waveform signal is superimposed, the waveform signal is extracted. in this way,
Since a sine wave signal having no phase shift from the original sine wave signal is generated and a waveform signal is extracted, the waveform signal can be extracted without being distorted on the time axis.

According to the second aspect of the present invention, since the phase displacement means comprises a differentiating circuit or an integrating circuit, it can be simply constructed.

[0011]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a preferred embodiment of a device for separating a waveform signal superimposed on a sine wave signal according to the present invention. FIG. 1 shows an outline of a power line communication system using a waveform signal separation device according to a first embodiment of the present invention.

The waveform information from spread spectrum transmitter 60 is superimposed on a sine wave power signal on power line 90 by adder 70. The waveform signal separation device 10 separates the waveform information superimposed on the sine wave power signal on the power line 90 and sends it to the spread spectrum receiver 50 side.

The configuration of the waveform signal separating device 10 will be described with reference to FIG. Here, assuming that the sine wave power signal on the power line 90 is Asin (2πft) and the information signal of the spread spectrum transmitter 60 shown in FIG. 1 is H (t), the adder 70 converts the information signal onto the sine wave power signal. The superimposed signal, that is, the signal carried on the power line 90 is Asin
(2πft) + H (t).

The low-pass filter 12 having the filter operator F (x) and the amplification factor b outputs the signal Asin (2πft) + H
Let (t) be bA sin (2πft + φ). That is, the information signal H (t) which is a high frequency component is removed. At this time, the phase is advanced (delayed) by φ while amplifying by b. And
The amplifier 14 having an amplification factor of 1 / b cancels the amount of b amplified by the low-pass filter 12, and outputs Asin (2πft)
+ Φ) is output.

Differentiator 1 with operator D (x) and amplification factor 2πfc
6 shifts the phase of the input Asin (2πft + φ) signal by 90 ° to 2πfcAcos (2πft + φ). Then, the amplifier 18 having an amplification factor of 1 / 2πfc cancels out 2πfc amplified by the low-pass filter 12, and outputs Acos (2πft + φ).

The phase converter 20 including the amplifier 22, the adder 24, and the amplifier 26 generates a sine wave power signal Asin (2πft) on the power line 90 from the above signal. That is, the signal Asin (2πft + φ) from the amplifier 14 is cos
Asin (2πft) at the amplifier 26 having an amplification factor of −φ
+ Φ) (cos−φ) and is added to the adder 24.
On the other hand, the signal Acos (2πft +
φ) is Aco by an amplifier 22 having a gain of sin−φ.
s (2πft + φ) (sin−φ) is applied to the adder 24. The adder 26 outputs the signal Asin (2πft)
+ Φ) (cos −φ) and signal Acos (2πft + φ)
(Sin−φ) to obtain a sine wave signal Asi
n (2πft) is output from the addition theorem.

The subtractor 30 subtracts the sine wave signal Asin (2πft) from the phase converter 20 from the signal Asin (2πft) + H (t) carried on the power line 90, thereby obtaining a spread spectrum transmitter. 60 information signals H
Take out (t). Here, the sine wave signal Asin (2πft) from the phase converter 20 is converted into a carrier wave Asin (2πft) in the signal Asin (2πft) + H (t) carried on the power line 90.
Since there is no phase shift from (πft), the information signal H (t) can be extracted without any distortion on the time axis. In the above example, the signal passed through the low-pass filter 12 is given a 90 ° shift by the differentiator 16, but a 90 ° shift can be given by using an integrator.

Here, the results of an experiment conducted on signal processing by the waveform signal separating device 10 will be described with reference to the waveform diagrams of FIGS. FIG. 7A shows a sine wave power signal on the power line 90 as a waveform A and an information signal as a waveform B. The waveform A is a commercial AC frequency of 60 Hz on the power line 90 shown in FIG. 1, and the waveform B corresponds to an information signal from the spread spectrum transmitter 60 in FIG.

The waveform C shown in FIG. 7B is a signal waveform obtained by superimposing the information signal B on the sine wave power signal A shown in FIG. 7A. FIG. 7B also shows the information signal B for comparison. FIG. 7C is an enlarged view of FIG. 7B. That is, the waveform C is a waveform on the output side of the adder 70 in FIG.

A waveform D shown in FIG. 8A is a signal waveform that has passed through the low-pass filter 12 shown in FIG. FIG.
(A) shows a waveform C before passing through the low-pass filter 12.
Are also shown for comparison. Although the information signal B is removed by the low-pass filter 12 as described above, a phase shift occurs.

A waveform E shown in FIG. 8B is a signal waveform that has passed through the differentiator 16 shown in FIG. FIG. 8B also shows the waveform D before passing through the differentiator 16 for comparison. As described above, the phase is shifted by 90 ° in the differentiator 16.

A waveform F shown in FIG. 8C is a signal waveform that has passed through the phase converter 20 shown in FIG. FIG. 8C also shows a waveform E before passing through the phase converter 20 for comparison. As described above, the phase shift given by the phase converter 20 when passing through the low-pass filter 12 is restored.

FIG. 9A shows a signal waveform C obtained by superimposing an information signal B on the sine wave power signal A shown in FIG.
FIG. 9B shows the sine wave power signal F whose phase has been restored by the phase converter 20 shown in FIG. 8C, and FIG.
The signal of (A) is shown enlarged. As can be seen from the figure, there is no phase shift between the signal waveform C and the sine wave power signal F whose phase has been restored.

FIG. 10A shows a signal waveform C obtained by superimposing an information signal B on the sine wave power signal A shown in FIG.
10 and an information waveform E separated from the signal waveform C by the subtractor 30 shown in FIG. 2, and FIG. 10B shows the signal of FIG. 10A in an enlarged manner. . As can be seen from the figure, the information waveform E is not distorted on the time axis from the source information signal B shown in FIG. That is, the carrier Asin in the signal Asin (2πft) + H (t) to be carried
(2πft) generated signal Asin (2
πft), the information signal H (t) is extracted without any distortion on the time axis.

The waveform signal separating apparatus 10 described above with reference to FIG. 2 includes a sine wave carrier signal shifted in phase by the low-pass filter 12 and a 90 ° phase shift in the sine wave carrier signal. The source sine wave carrier signal was reproduced by adding the applied signal. Here, the separation device for a waveform signal superimposed on a sine wave signal of the present invention can reproduce the source sine wave carrier signal by giving an arbitrary phase shift instead of 90 °. This configuration will be described with reference to the block diagram of the waveform signal separation device shown in FIG.

In this modification, the first linear filter 62
, The sine wave power signal Asin (2
πft) + H (t) when removing the information signal H (t),
The phase advance of φ is given, the phase advance of 与 え is given by the second linear filter 66, and the sine wave power signal Asin (2πft) is generated by the phase converter 80.

This principle will be described in more detail. Time: t Phase advance of first linear filter operator: φ Phase advance of second linear filter operator: 増 幅 Amplification rate of first and second linear filter operators: b1, b2 First and second linear filter operators: F1 (X), F2 (x
) (Phase advance, amplification factor) of Fl (x) and F2 (x) are defined as (bl, φ) and (b2, ψ), respectively. Amplification rate of indefinite integral operator: c1 Indefinite integral operator: (1 / D) (x) Amplification rate of differential operator: c2 Differential operator: D (x) Amplification operator: (1 / b) = x / b, (1 / 2πfc)
(X) = x / 2πfc, d (x) = d · x, e (x) =
e · x An elutriation wave information signal having amplitude A and frequency f: Asin (2π
ft) Arbitrary waveform signal having fundamental frequency fh: H (t) Composite waveform information signal: A on which arbitrary waveform information signal is superimposed
It is defined as sin (2πft) + H (t).

When fh ≠ f is satisfied, using an appropriate linear filter, F1 (A sin (2πft) + H (t)) = b 1A sin
(2πft + φ) F2 (A sin (2π ft) + H (t)) = b 2A sin
(2πft + ψ) holds. By the indefinite integral operator, (1 / D) (Asin (2πft + φ)) = − (c1 / 2πf) Acos (2πft + φ) = (c1 / 2πf) + Asin (2πft + φ−π / 2) By the differential operator, D (Asin (2πft + φ)) = 2πfc2Acos (2πft + φ) = − 2πfc2Asin (2πft + φ−π / 2) Therefore, for a sine wave information signal,
The indefinite integral operator and the differential operator are represented by a linear filter operator F
2 (x), they are also included in the linear filter operator F2 (x).

By the sine wave addition theorem or the rotation transformation,

(Equation 1)

(Equation 2) sin (2πft + φ) = sin (φ) · cos (2πft) + cos
(φ) sin (2πft) sin (2πft + ψ) = sin (ψ) cos (2πft) + cos
(ψ) ・ sin (2πft) holds,

(Equation 3) Since there exists φ and ψ that satisfy the following equation, sin (2πft) = d · sin (2πft + φ) + e · sin
(2πft + ψ) d = −sin (ψ) / sin (φ−ψ) e = sin (φ) / sin (φ−ψ)

Therefore, when the following information signal processing method is constructed from the above operators, the following expression is established. H (t) =
Asin (2πft) + H (t)-[d · F1 (Asin
(2πft) + H (t)) + eF2 (Asin (2πf)
t)) + H (t))]

As with the waveform signal separating apparatus described with reference to FIG. 2, the amplifier 82, the adder 84, and the amplifier 8 shown in FIG.
6 from the signal to the power line 90
Sine wave power signal Asin (2πft) is generated. That is, the signal Asin from the amplifier 68 (2πft + ψ)
Is an amplifier 86 having an amplification factor e that satisfies the conditions described above.
Is applied to the adder 82. On the other hand, the amplifier 64
Is applied to an adder 84 via an amplifier 86 having an amplification factor d satisfying the above-described condition. The adder 84 adds the two signals to output a sine wave signal Asin (2πft) from the above-described addition theorem / rotation theorem.

The subtractor 88 subtracts the sine wave signal Asin (2πft) from the phase converter 20 from the signal Asin (2πft) + H (t) carried on the power line 90, thereby producing a spread spectrum transmitter. 60 information signals H
Take out (t). Here, the sine wave signal Asin (2πft) from the phase converter 80 is converted into a carrier Asin (2πft) in the signal Asin (2πft) + H (t) carried on the power line 90.
Since there is no phase shift from (πft), the information signal H (t) can be extracted without any distortion on the time axis.

Next, a second embodiment of the present invention will be described with reference to FIGS. FIG. 4 shows an outline of a wireless communication system using a waveform signal separation device according to a second example of the present embodiment.

The waveform information multiplexed by the spread spectrum transmitter 60 is transmitted as a radio wave by the transmitter 170 being superimposed on a high frequency sine wave carrier signal. Receiver 17
2 receives the radio wave transmitted from the transmitter and outputs it to the waveform signal separation device 110 side. The waveform signal separation device 110
The waveform information superimposed on the sine wave carrier signal is separated and transmitted to the spread spectrum receivers 50A and 50B. In the second embodiment, the spread spectrum transmitter 6
0 multiplexes and sends information to spread spectrum receivers 50A and 50B, and each of the spread spectrum receivers 50A and 50B separates the multiplexed information after reception.

The configuration of the waveform signal separating device 110 will be described with reference to FIG. Here, assuming that the sine wave carrier signal is Asin (2πft) and the information signal of the spread spectrum transmitter 60 shown in FIG. 4 is H (t), the signal carried by radio is expressed as Asin (2πft) + H (t). Is done.

The high-pass filter 112 outputs the signal Asi
Let n (2πft) + H (t) be bAsin (2πft + φ). That is, the information signal H (t) which is a low frequency component is removed.
The subsequent operation is the same as that of the first embodiment described with reference to FIG.

Next, a third embodiment of the present invention will be described with reference to FIG. FIG. 6 shows an outline of an optical communication system using a waveform signal separation device according to a third example of the present embodiment.

The waveform information multiplexed by the spread spectrum transmitter 60 is superimposed on a high-frequency sine wave carrier signal by the transmitter 270 and transmitted to the optical fiber 280 as an optical signal. The receiver 272 receives the optical signal transmitted from the transmitter and outputs the optical signal to the waveform signal separating device 210 side. The waveform signal separation device 210 separates the waveform information superimposed on the sine wave carrier signal, and sends it to the spread spectrum receiver 50 side. Note that the waveform signal separation device 2 of the third embodiment
10 is the same as the second embodiment described above with reference to FIG.

[0039]

As described above, according to the present invention, a sine wave signal is extracted from a sine wave signal on which a waveform signal is superimposed by a filter, a phase shift is given to the extracted sine wave signal, and the sine wave signal is extracted by the filter. The added sine wave signal and the sine wave signal with the phase shift are added to generate a sine wave signal before the waveform signal is superimposed. Then, by subtracting the generated sine wave signal from the sine wave signal on which the waveform signal is superimposed, the waveform signal is extracted. As described above, since a sine wave signal having no phase shift from the original sine wave signal is generated and a waveform signal is extracted, the waveform signal can be extracted without being distorted on the time axis, and thus the spectrum can be extracted. In spreading communication, it can be suitably used when reproducing a transmitted signal.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a communication system according to a first embodiment of the present invention.

FIG. 2 is a block diagram of the waveform signal separation device shown in FIG.

FIG. 3 is a block diagram according to a modification of the waveform signal separation device shown in FIG.

FIG. 4 is an explanatory diagram showing a communication system according to a second embodiment of the present invention.

5 is a block diagram of the waveform signal separation device shown in FIG.

FIG. 6 is an explanatory diagram showing a communication system according to a third embodiment of the present invention.

FIGS. 7A, 7B, and 7C are waveform diagrams of respective parts of the communication system according to the first embodiment of the present invention.

8 (A), 8 (B), and 8 (C) are waveform diagrams of respective parts of the communication system according to the first embodiment of the present invention.

FIGS. 9A and 9B are waveform diagrams of respective parts of the communication system according to the first embodiment of the present invention.

FIGS. 10A and 10B are waveform diagrams of respective parts of the communication system according to the first embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Waveform signal separation apparatus 12 Low-pass filter 14 Amplifier 16 Differentiator 18 Amplifier 20 Phase converter 30 Subtractor 50 Spread spectrum receiver 60 Spread spectrum transmitter 70 Adder

Claims (3)

[Claims] 1. A filter for extracting a sine wave signal from a sine wave signal on which a waveform signal is superimposed; phase shift means for giving a phase shift to the sine wave signal extracted by the filter; and a sine extracted by the filter. A wave signal and a sine wave signal to which a phase shift has been given by the phase shifting means, to generate a sine wave signal before the waveform signal is superimposed; and the phase conversion means And a subtracting means for subtracting the generated sine wave signal from the sine wave signal on which the waveform signal is superimposed, thereby extracting the waveform signal. . 2. The apparatus for separating a waveform signal superimposed on a sine wave signal according to claim 1, wherein said phase shifting means comprises a differentiating circuit or an integrating circuit. 3. A step of extracting a sine wave signal from a sine wave signal on which a waveform signal is superimposed by a filter, a step of giving a phase shift to the sine wave signal extracted by the filter, and a sine extracted by the filter. Generating a sine wave signal before the waveform signal is superimposed, by adding the wave signal and the sine wave signal given the phase shift by the step, Subtracting the waveform signal from the sine wave signal on which the waveform signal is superimposed to extract the waveform signal, and separating the waveform signal superimposed on the sine wave signal.