JP2009027699A - Ssb signal receiver - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an SSB signal receiver for demodulating an original signal more correctly as compared with a conventional case and removing noises on acoustic feeling, by performing calculation with a divider other than zero at any case in division processing for obtaining a demodulation signal of an SSB signal. <P>SOLUTION: In the SSB signal receiver 1, by using a formula derived with a divisor signal S181 of a divider 190, which is not zero, the maximum amplitude of a carrier component S911 as an output signal of a noise removal circuit 900 and the maximum amplitude of an SSB signal component S912 are adjusted by amplitude ratio regulators 910, 920 (amplifier or attenuator). Here, A is the maximum amplitude of the carrier component S911, B is the maximum amplitude of the SSB signal component S912, G is an amplification degree of phase shifter 50, and ϕ is the phase shift amount. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an SSB (Single Side Band) signal receiving apparatus including amplitude distortion, and more particularly to a receiving apparatus used for medium wave broadcasting, short wave broadcasting, radio telephone, radio paging, radio control, radio beacon and the like. It is about.

  2. Description of the Related Art Conventionally, an SSB signal receiving device used for medium wave broadcasting, short wave broadcasting, wireless telephone, wireless calling, wireless control, wireless beacon and the like is known (for example, see Patent Document 1). This SSB signal refers to a sideband signal having only an LSB component and a USB component when the modulated wave is developed into a carrier component, an LSB component, and a USB component. In such a communication system using an SSB signal, a carrier component is not included at the time of transmission, so that the amount of transmission power can be reduced and the efficiency of transmission power can be improved.

  FIG. 1 is a diagram illustrating a configuration of a conventional SSB signal receiving apparatus. The SSB signal receiving apparatus 2 is an apparatus that orthogonally demodulates an SSB signal with a carrier wave. The SSB signal with a carrier wave is a carrier component signal (hereinafter referred to as “carrier wave component”) S31 and an SSB signal component signal (hereinafter referred to as “carrier wave component”). , Referred to as “SSB signal component”.) After being separated into S32, re-synthesis, quadrature detection and signal calculation are performed without adjusting the amplitude ratio of these, and a demodulated signal S191 of the SSB signal is output. . In FIG. 1, the SSB signal receiving apparatus 2 includes a frequency conversion circuit 20, a carrier / signal separation circuit 30, an amplifier 40, a carrier / signal recombination circuit 80, quadrature detection circuits 100 and 110, a detection signal calculation circuit 200, and a divider 190. It has. Detailed description of each circuit will be described later.

  In such an SSB signal receiving apparatus 2, the divider 190 divides the signal S171 that is the dividend by the signal S181 that is the divisor, and outputs the division result as a demodulated signal S191 of the SSB signal (Patent Document 1, Paragraph 1). No. 0024).

JP 2007-81653 A

  However, in the conventional SSB signal receiving apparatus 2, when the signal S181 that is the divisor in the division processing of the divider 190 is zero, the demodulated signal S191 that is the division result of the divider 190 becomes indefinite, and the original signal is accurately demodulated. There was a problem that I could not. In order to solve this problem, it is assumed that a complementing process or the like is performed using a plurality of sampling values together with the division process by the divider 190. However, when such a complementing process is performed, the demodulated signal S191 has a drawback that it contains significant noise in terms of hearing. Therefore, such a complementary process cannot be sufficiently dealt with.

  Therefore, the present invention has been made in view of such a problem. In the division processing for obtaining the demodulated signal of the SSB signal, in any case, calculation is performed with a divisor other than zero, and the original signal is more than conventional. An object of the present invention is to provide an SSB signal receiving apparatus capable of accurately demodulating and removing audible noise.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have found a means for generating a divisor that is not zero in any case in the division processing for obtaining the demodulated signal of the SSB signal. That is, in the SSB signal receiving apparatus, it has been found that the divisor does not become zero in any case by adjusting the maximum amplitude of the carrier component and the maximum amplitude of the SSB signal so as to satisfy the condition of Expression (900) described later. .

  First, an example of an SSB signal receiving apparatus to which the present invention is applied will be described. FIG. 2 is a diagram for explaining an example of the SSB signal receiving apparatus according to the present invention. This SSB signal receiver 1 is a device that demodulates an SSB signal to which a carrier wave is added by quadrature detection, and includes a frequency conversion circuit 20, a carrier wave / signal separation circuit 30, an amplifier 40, a noise removal circuit 900, a carrier wave / signal resynthesis. A circuit 80, quadrature detection circuits 100 and 110, a detection signal calculation circuit 200, and a divider 190 are provided.

  The frequency conversion circuit 20 converts the SSB signal to which the carrier wave is added into a signal having a certain intermediate frequency. The carrier / signal separation circuit 30 separates the carrier component S31 and the SSB signal component S32 from the intermediate frequency signal. The amplifier 40 amplifies the amplitude of the carrier wave component S31 and outputs the carrier wave component S41.

  The noise removal circuit 900 amplifies or attenuates the carrier component S41 and the SSB signal component S32 by the amplitude ratio adjusters 910 and 920 so as to satisfy the condition of the expression (900) described later, and the carrier component S911 and the SSB signal component S912 are obtained. Output. The carrier wave / signal recombination circuit 80 combines the carrier wave component S911 and the SSB signal component S912 by the synthesizer 60, and outputs a combined signal S61. The carrier component S51 obtained by amplifying and shifting the carrier component S911 by a predetermined amount by the phase shifter 50 is combined by the combiner 70 with the combiner 70, and a combined signal S71 is output. Here, the carrier component S911 and the carrier component S51 are signals having different signs, amplitudes, or phase shifts by the phase shifter 50.

  The quadrature detection circuits 100 and 110 perform quadrature detection on the combined signals S61 and S71. The detection signal calculation circuit 200 receives the quadrature detection signals of the in-phase component and the quadrature component from the quadrature detection circuits 100 and 110, respectively, performs a predetermined calculation, and obtains a dividend signal S171 and a divisor signal S181 for obtaining a demodulated signal S191. Output. The divider 190 divides by the dividend signal S171 and the divisor signal S181 and outputs a demodulated signal S191 of the SSB signal.

  In such an SSB signal receiving apparatus 1, the present invention is configured so that the maximum amplitude of the carrier component S 911 and the maximum of the SSB signal component S 912, which are output signals of the noise removal circuit 900, so that the divisor signal S 181 of the divider 190 does not become zero. The amplitude is adjusted by amplitude ratio adjusters 910 and 920 (amplifiers or attenuators). That is, the SSB signal receiving apparatus 1 uses a conditional expression (expression (900) described later) derived that the divisor signal S181 is not zero.

つまり、この式（９００）は除数信号Ｓ１８１が零でないときの条件式であるから、この式（９００）を満たすように、搬送波成分Ｓ９１１の最大振幅及びＳＳＢ信号成分Ｓ９１２の最大振幅を調整する。これにより、除数信号Ｓ１８１は零になることがない。 Specifically, the maximum amplitude of the carrier wave component S911 is A, the maximum amplitude of the SSB signal component S912 is B, the amplification degree of the phase shifter 50 provided in the carrier wave / signal recombining circuit 80 is G, and the phase shift amount is φ. In such a case, the condition of the following expression (900) is satisfied.

That is, since this equation (900) is a conditional equation when the divisor signal S181 is not zero, the maximum amplitude of the carrier component S911 and the maximum amplitude of the SSB signal component S912 are adjusted so as to satisfy this equation (900). Thereby, the divisor signal S181 does not become zero.

  That is, the SSB signal receiving apparatus according to the present invention is a SSB signal receiving apparatus that demodulates an SSB signal to which a carrier wave is added by quadrature detection. Based on the signal separation means, the amplitude adjustment means for adjusting the maximum amplitude based on the carrier wave component and the SSB signal component, the carrier wave component and the SSB signal component with the maximum amplitude adjusted, and the carrier wave component and the SSB signal component A carrier wave / signal synthesizing means for generating a carrier wave component having a different sign, amplitude or phase from the carrier wave component, synthesizing the generated carrier wave component and the SSB signal component, and outputting these two synthesized signals; A quadrature detection means for quadrature detection of each of the two combined signals and outputting a quadrature detection signal; and the quadrature detection means Detection signal calculation means for generating a demodulated signal of the SSB signal by division calculation using the orthogonal detection signal output from the signal, and detection signal calculation by adjusting the maximum amplitude of the carrier wave component and SSB signal component by the amplitude adjustment means The divisor in the division operation of the means is prevented from becoming zero.

  In the SSB signal receiving apparatus according to the present invention, the carrier wave / signal combining unit includes a phase shifter for generating carrier wave components having different codes, amplitudes, or phases, and the amplitude adjusting unit When the maximum amplitude of the carrier wave component is A, the maximum amplitude of the SSB signal component after amplitude adjustment is B, the amplification degree of the phase shifter is G, and the phase shift amount is φ, the condition of the above-described equation (900) is satisfied. The maximum amplitude of the carrier wave component and the maximum amplitude of the SSB signal component are adjusted so as to satisfy.

  In this case, it is desirable that the phase shift amount φ of the phase shifter is −3π / 2 or −π / 2. The phase shift amount φ of the phase shifter is preferably −2π <φ ≦ 0 (where φ ≠ −π, 0).

  As described above, according to the present invention, the division processing for obtaining the demodulated signal of the SSB signal is performed with a divisor other than zero. As a result, the demodulated signal does not become indefinite, and the original signal can be demodulated more accurately than before, and audible noise can be removed.

  The best mode for carrying out the present invention will be described below in detail with reference to the drawings. The first embodiment is an example in which, in the phase shifter 50 provided in the carrier wave / signal recombining circuit 80, the amplification degree G = 1 and the phase shift amount φ = −3π / 2 (3π / 2 slow phase) are set. In the phase shifter 50, Example 2 shows an example in which the amplification degree G = 1 and the phase shift amount φ = −π / 2 (slow phase of π / 2) are set. In the phase shifter 50, an arbitrary amplification degree G is set, and the phase shift amount φ is set to −2π <φ ≦ 0 (where φ ≠ −π. , 0) is shown as an example. Hereinafter, Examples 1 to 3 will be described. Note that the numbers of the mathematical expressions are the same as those of the signal S shown in the figure.

[Example 1]
First, Example 1 will be described. The first embodiment is an example in which, in the phase shifter 50 provided in the carrier wave / signal recombining circuit 80, the amplification degree G = 1 and the phase shift amount φ = −3π / 2 (3π / 2 slow phase) are set. It is. FIG. 3 is a diagram showing the configuration of the SSB signal receiving apparatus (Example 1) according to the embodiment of the present invention.

Example 1 / Configuration
First, the configuration of the SSB signal receiving device 1-1 will be described. The SSB signal receiving device 1-1 includes a frequency conversion circuit 20, a carrier wave / signal separation circuit 30, an amplifier 40, a noise removal circuit 900, a carrier wave / signal resynthesis circuit 80, quadrature detection circuits 100 and 110, and a detection signal calculation circuit 200. -1 and a divider 190 are provided. The noise removal circuit 900 includes amplitude ratio adjusters 910 and 920 that are amplifiers or attenuators. The carrier wave / signal recombination circuit 80 includes a phase shifter 50 and combiners 60 and 70. Includes a phase shifter 101, multipliers 102 and 103, and LPFs (low-pass filters) 104 and 105, and a quadrature detection circuit 110 includes a phase shifter 111, multipliers 112 and 113, and LPFs 114 and 115. The signal arithmetic circuit 200-1 includes multipliers 130, 140, 150 and subtracters 170, 180.

  Comparing the conventional SSB signal receiving device 2 shown in FIG. 1 with the SSB signal receiving device 1-1 of the first embodiment shown in FIG. 3, both devices include a frequency conversion circuit 20, a carrier / signal separation circuit 30, an amplifier. 40, the quadrature detection circuits 100 and 110, the detection signal calculation circuit 200 (200-1), and the divider 190 are common, but the SSB signal reception device 1-1 has the same configuration as the SSB signal reception device 2. In addition, it is different in that a noise removal circuit 900 is provided.

  When the SSB signal receiving apparatus 1-1 receives the SSB signal to which the carrier wave is added, the frequency conversion circuit 20 converts the SSB signal to which the carrier wave is added into a signal having a certain intermediate frequency. The carrier wave / signal separation circuit 30 receives the intermediate frequency signal frequency-converted by the frequency conversion circuit 20, and separates the carrier wave component S31 and the SSB signal component S32 from the signal. The amplifier 40 amplifies the amplitude of the carrier component S31 separated by the carrier / signal separation circuit 30.

  The noise removal circuit 900 inputs the carrier wave component S41 amplified by the amplifier 40 and the SSB signal component S32 separated by the carrier wave / signal separation circuit 30, respectively, so as to meet the condition of the above-described equation (900). The carrier component S41 and the SSB signal component S32 are amplified or attenuated, and the carrier component S911 and the SSB signal component S912 are output. Specifically, the amplitude ratio adjuster 910 amplifies or attenuates the carrier wave component S41 so as to meet the condition of Expression (900), and outputs the carrier wave component S911. In addition, the amplitude ratio adjuster 920 amplifies or attenuates the SSB signal component S32 so as to meet the condition of Expression (900), and outputs an SSB signal component S912. In Equation (900), A is the maximum amplitude of the carrier component S911, B is the maximum amplitude of the SSB signal component S912, G is the amplification factor of the phase shifter 50 provided in the carrier / signal recombining circuit 80, and φ is The amount of phase shift of the phase shifter 50 is shown respectively. In the case of the first embodiment, since G = 1 and φ = −3π / 2, A / B> √2.

  The carrier wave component S911 that is an output signal of the noise removal circuit 900 includes a phase shifter 50 and a combiner 60 of the carrier wave / signal recombination circuit 80, and a phase shifter 101, a multiplier 103, and a quadrature detection circuit of the quadrature detection circuit 100. 110 are respectively supplied to the phase shifter 111 and the multiplier 113. Also, the SSB signal component S912 that is the output signal of the noise removal circuit 900 is supplied to the combiners 60 and 70 of the carrier wave / signal recombination circuit 80, respectively.

  The carrier / signal recombining circuit 80 receives the carrier component S911 and the SSB signal component S912 from the noise removal circuit 900, combines the carrier component S911 and the SSB signal component S912, outputs a combined signal S61, and outputs the carrier component S911. Are combined with the carrier component S51 and the SSB signal component S912 shifted in phase by −3π / 2, and a combined signal S71 is output. Specifically, the combiner 60 combines the carrier component S911 and the SSB signal component S912, and outputs a combined signal S61. The phase shifter 50 shifts the carrier component S911 by -3π / 2 and outputs the carrier component S51, and the combiner 70 combines the carrier component S51 and the SSB signal component S912 from the phase shifter 50. The synthesized signal S71 is output.

  The combined signal S61 that is an output signal of the carrier wave / signal recombining circuit 80 is supplied to the multipliers 102 and 103 of the quadrature detection circuit 100, and the combined signal S71 is supplied to the multipliers 112 and 113 of the quadrature detection circuit 110, respectively. Is done.

  The quadrature detection circuit 100 receives the composite signal S61 from the carrier wave / signal recombination circuit 80, receives the carrier wave component S911 from the noise removal circuit 900, performs quadrature detection on the composite signal S61, and generates the quadrature detection signal S101 of the in-phase component. The quadrature component quadrature detection signal S102 is output. Specifically, the multiplier 102 multiplies the signal obtained by shifting the carrier component S911 by −π / 2 by the phase shifter 101 and the combined signal S61, and the LPF 104 filters the signal multiplied by the multiplier 102. Processing is performed to remove high frequency components, and quadrature detection signal S102 of quadrature components is output. The multiplier 103 multiplies the carrier wave component S911 and the combined signal S61, and the LPF 105 filters the signal multiplied by the multiplier 103 to remove a high frequency component, and a quadrature detection signal having an in-phase component. S101 is output.

  An in-phase component quadrature detection signal S101, which is an output signal of the quadrature detection circuit 100, is supplied to the multipliers 130 and 150 of the detection signal arithmetic circuit 200-1, respectively, and the quadrature component quadrature detection signal S102 is supplied to the detection signal arithmetic circuit 200. −1 multiplier 140.

  The quadrature detection circuit 110 receives the composite signal S71 from the carrier wave / signal recombination circuit 80, receives the carrier wave component S911 from the noise removal circuit 900, performs quadrature detection on the composite signal S71, and generates the quadrature detection signal S111 of the in-phase component. The quadrature component quadrature detection signal S112 is output. Specifically, the multiplier 112 multiplies the signal obtained by shifting the carrier component S911 by −π / 2 by the phase shifter 111 and the combined signal S71, and the LPF 114 filters the signal multiplied by the multiplier 112. Processing is performed to remove the high frequency component, and the quadrature detection signal S112 of the quadrature component is output. The multiplier 113 multiplies the carrier wave component S911 and the combined signal S71, and the LPF 115 filters the signal multiplied by the multiplier 113 to remove the high-frequency component, and the quadrature detection signal of the in-phase component S111 is output.

  An in-phase component quadrature detection signal S111, which is an output signal of the quadrature detection circuit 110, is supplied to the multipliers 140 and 150 of the detection signal arithmetic circuit 200-1, respectively, and the quadrature component quadrature detection signal S112 is supplied to the detection signal arithmetic circuit 200. −1 multiplier 130.

  The detection signal calculation circuit 200-1 outputs the quadrature detection signal S101 and quadrature detection signal S102 of the in-phase component from the quadrature detection circuit 100, and the quadrature detection signal S111 and quadrature detection of the quadrature component from the quadrature detection circuit 110. The signal S112 is input, a predetermined calculation is performed, and a dividend signal S171 and a divisor signal S181 for obtaining a demodulated signal S191 are output. Specifically, the multiplier 130 multiplies the quadrature detection signal S101 having the in-phase component and the quadrature detection signal S112 having the quadrature component, and outputs a signal S131. The multiplier 140 multiplies the quadrature detection signal S102 having the quadrature component by the quadrature detection signal S111 having the in-phase component, and outputs a signal S141. Multiplier 150 multiplies quadrature detection signal S101 having the in-phase component and quadrature detection signal S111 having the in-phase component, and outputs signal S151. The subtractor 170 subtracts the signal S141 output from the multiplier 140 from the signal S151 output from the multiplier 150, and outputs a dividend signal S171. The subtracter 180 subtracts the signal S131 output from the multiplier 130 from the signal S141 output from the multiplier 140, and outputs a divisor signal S181.

  The dividend signal S171 and the divisor signal S181, which are output signals of the detection signal arithmetic circuit 200-1, are supplied to the divider 190.

  Divider 190 receives dividend signal S171 and divisor signal S181 from detection signal arithmetic circuit 200-1, performs division, and outputs demodulated signal S191 of the SSB signal.

[Example 1 / Signal]
Next, signals in the SSB signal receiving device 1-1 shown in FIG. 3 will be described. The carrier wave component S911 output from the noise removal circuit 900 is expressed by the following equation where the waveform with respect to time t when the maximum amplitude is 1 is cos (ωt) and the maximum amplitude is A.
A × cos (ωt) (911)
Also, the SSB signal component S912 output from the noise removal circuit 900 is expressed by the following equation, where f (t) is a waveform with respect to time t when the maximum amplitude is 1, and B is the maximum amplitude.
B x f (t) (912)
Here, in a transmission device that transmits an SSB signal to which a carrier wave is added, a baseband signal before modulation is represented by g (t), and a signal obtained by performing Hilbert transform on this signal is represented by h (t). The SSB signal, that is, f (t), is expressed by the following equation.
f (t) = g (t) × cos (ωt) + h (t) × sin (ωt)
Therefore, the synthesized signal S61 output from the synthesizer 60 and the synthesized signal S71 output from the synthesizer 70 are expressed by the following equations, where the amplification degree of the phase shifter 50 is G and the phase shift amount is φ. The
Acos (ωt) + B {g (t) cos (ωt) + h (t) sin (ωt)} (61)
AGcos (ωt + φ) + B {g (t) cos (ωt) + h (t) sin (ωt)} (71)

  In-phase quadrature detection signal S101 and quadrature-component quadrature detection signal S102 output by quadrature detection circuit 100, and in-phase component quadrature detection signal S111 and quadrature-component quadrature detection signal S112 output by quadrature detection circuit 110 Is represented by the following equation.

また、直交検波回路１００のＬＰＦ１０５により高次周波数信号（２ωｔを含む項）が除去されるから、以下の式で表される。

Since the in-phase component quadrature detection signal S101 is (101) = (61) × (911),

Further, since the high-order frequency signal (term including 2ωt) is removed by the LPF 105 of the quadrature detection circuit 100, it is expressed by the following equation.

また、直交検波回路１００のＬＰＦ１０４により高次周波数信号（２ωｔを含む項）が除去されるから、以下の式で表される。

Since the quadrature detection signal S102 of the quadrature component is (102) = (61) × (911) (where (911) is a signal delayed by 90 °).

Further, since the high-order frequency signal (term including 2ωt) is removed by the LPF 104 of the quadrature detection circuit 100, it is expressed by the following equation.

また、直交検波回路１１０のＬＰＦ１１５により高次周波数信号（２ωｔを含む項）が除去されるから、以下の式で表される。

Since the in-phase component quadrature detection signal S111 is (111) = (71) × (911),

Further, since the high-order frequency signal (term including 2ωt) is removed by the LPF 115 of the quadrature detection circuit 110, it is expressed by the following equation.

また、直交検波回路１１０のＬＰＦ１１４により高次周波数信号（２ωｔを含む項）が除去されるから、以下の式で表される。

Since the quadrature detection signal S112 of the quadrature component is (112) = (71) × (911) (where (911) is a signal delayed by 90 °).

Further, since the high-order frequency signal (term including 2ωt) is removed by the LPF 114 of the quadrature detection circuit 110, it is expressed by the following equation.

Therefore, the dividend signal S171 of the divider 190 is (171-1) = (101) × (111) − (102) × (111) = {(101) − (102)} × (111). It is expressed by the following formula.

Further, the divisor signal S181 of the divider 190 is (181) = (102) × (111) − (101) × (112), and is expressed by the following equation.

In Example 1, since the amplification degree G = 1 of the phase shifter 50 and the phase shift amount φ = −3π / 2, when these are substituted into the equations (171-1) and (181), the following equations are respectively obtained: It is represented by

Therefore, the demodulated signal S191 output from the divider 190 is (191-1) = (171-1 ′) ÷ (181-1 ′), and is expressed by the following equation.

  From this equation, it can be seen that the component of the baseband signal g (t) before modulation is obtained from the demodulated signal S191. It can also be seen that an accurate SSB signal demodulated signal can be obtained without using amplitude information.

ここで、ｆ（ｔ）＝ｇ（ｔ）ｃｏｓ（ωｔ）＋ｈ（ｔ）ｓｉｎ（ωｔ）より

で、表されるから、式（１８１−０）にｇ（ｔ）,ｈ（ｔ）を代入して、

となる。ここで、ｆ（ｔ）は１を最大振幅とするから、時間ｔの変化により、

は、

の範囲をとり、最大値は１である。
また、ｓｉｎ｛θ（ｔ）+α｝は、−１≦ｓｉｎ｛θ（ｔ）+α｝≦＋１の範囲の値をとり、絶対値の最大値は１である。したがって、どのようなｇ（ｔ）,ｈ（ｔ）であっても上式が成立するための条件は、以下の式で表される。

本実施例１の場合、Ｇ＝１及びφ＝−３π／２であるから、Ａ／Ｂ＞√２となる。 By the way, the condition for the divisor signal S181 not to be zero is (181) ≠ 0, and is expressed by the following equation.

Here, f (t) = g (t) cos (ωt) + h (t) sin (ωt)

Therefore, substituting g (t) and h (t) into the equation (181-0),

It becomes. Here, since f (t) has 1 as the maximum amplitude, the change of time t

Is

The maximum value is 1.
Sin {θ (t) + α} takes a value in the range of −1 ≦ sin {θ (t) + α} ≦ + 1, and the maximum absolute value is 1. Therefore, the condition for satisfying the above equation for any g (t), h (t) is expressed by the following equation.

In the case of the first embodiment, since G = 1 and φ = −3π / 2, A / B> √2.

  FIG. 7 is a waveform diagram of the demodulated signal S191 output from the SSB signal receiving device 1-1 according to the first embodiment illustrated in FIG. FIG. 6 is a waveform diagram of the demodulated signal S191 output from the conventional SSB signal receiving apparatus 2 shown in FIG. According to FIG. 6, it can be seen that the demodulated signal S191 of the conventional SSB signal receiving apparatus 2 contains significant noise. On the other hand, according to FIG. 7, the demodulated signal S191 of the SSB signal receiving apparatus 1-1 of the first embodiment does not contain significant noise and is removed by the SSB signal receiving apparatus 1-1. Recognize.

  As described above, according to the SSB signal receiving device 1-1 of the first embodiment, the amplification value G = 1 of the phase shifter 50 and the phase shift amount φ = −3π / 2 are set as the design values. The amplitude ratio adjuster of the noise removal circuit 900 is set so that the ratio of the maximum amplitude A of the carrier wave component S911 and the maximum amplitude B of the SSB signal component S912, which is an output signal of the noise removal circuit 900, satisfies the condition of Expression (900). By setting the amplification factor of the amplifiers 910 and 920 or the attenuation factor of the attenuator, the divisor signal S181 of the divider 190 does not become zero in any case. Therefore, since the demodulated signal S191 that is the output signal of the divider 190 does not become indefinite in any case, it is possible to demodulate the original signal more accurately than before, and to remove audible noise.

  Further, according to the SSB signal receiving device 1-1 of the first embodiment, since the phase shift amount φ = −3π / 2, the right side of the equation (900) is minimized. As a result, A / B can be reduced as compared with other phase shift amounts, so that the amplitude of the demodulated signal S191 can be increased (see equation (191-1)). Therefore, in the process using the demodulated signal S191, the signal-to-noise power ratio can be increased.

[Example 2]
Next, Example 2 will be described. The second embodiment is an example in which, in the phase shifter 50 provided in the carrier wave / signal recombining circuit 80, the amplification degree G = 1 and the phase shift amount φ = −π / 2 (slow phase of π / 2) are set. It is. FIG. 4 is a diagram showing the configuration of the SSB signal receiving apparatus (Example 2) according to the embodiment of the present invention.

[Example 2 / Configuration]
First, the configuration of the SSB signal receiving device 1-2 will be described. The SSB signal receiving device 1-2 includes a frequency conversion circuit 20, a carrier wave / signal separation circuit 30, an amplifier 40, a noise removal circuit 900, a carrier wave / signal resynthesis circuit 80, quadrature detection circuits 100 and 110, and a detection signal calculation circuit 200. -2 and a divider 190. The noise removal circuit 900 includes amplitude ratio adjusters 910 and 920, the carrier wave / signal recombination circuit 80 includes a phase shifter 50 and combiners 60 and 70, and the quadrature detection circuit 100 includes a phase shifter 101. , Multipliers 102 and 103 and LPFs 104 and 105, quadrature detection circuit 110 includes phase shifter 111, multipliers 112 and 113, and LPFs 114 and 115, and detection signal calculation circuit 200-2 includes multipliers 130 and 140. 150, a sign inverter 160, and subtracters 170, 180.

  When the SSB signal receiving device 1-1 of the first embodiment shown in FIG. 3 and the SSB signal receiving device 1-2 of the second embodiment shown in FIG. 4 are compared, the basic configuration of both devices is the same. The difference is that the detection signal arithmetic circuit 200-2 of the receiving device 1-2 includes a sign inverter 160. This difference is that in the first embodiment, the phase shifter 50 sets the amplification degree G = 1 and the phase shift amount φ = −3π / 2, and in the second embodiment, the phase shifter 50 sets the amplification degree G = 1 and This is because the phase amount φ = −π / 2 is set. In the following, in FIG. 4, the same reference numerals as those in FIG. The phase shifter 50 of the carrier wave / signal recombining circuit 80 shifts the carrier wave component S911 by −π / 2 and outputs the carrier wave component S51.

  In FIG. 4, the noise removal circuit 900 inputs the carrier wave component S41 amplified by the amplifier 40 and the SSB signal component S32 separated by the carrier wave / signal separation circuit 30 so that the divisor signal S181 does not become zero. The carrier wave component S32 and the carrier wave component S41 are amplified or attenuated so as to meet the condition of the expression (900) described above, and the carrier wave component S911 and the SSB signal component S912 are output, as in the first embodiment. In this case, since G = 1 and φ = −π / 2, A / B> √2.

  Further, the detection signal calculation circuit 200-2 receives the in-phase component quadrature detection signal S101 and the quadrature component quadrature detection signal S102 from the quadrature detection circuit 100, and the quadrature detection circuit 110 outputs the in-phase component quadrature detection signal S111 and quadrature component. The quadrature detection signal S112 is input, a predetermined calculation is performed, and a dividend signal S171 and a divisor signal S181 for obtaining a demodulated signal S191 are output. Specifically, the multiplier 130 multiplies the quadrature detection signal S101 having the in-phase component and the quadrature detection signal S112 having the quadrature component, and outputs a signal S131. The multiplier 140 multiplies the quadrature detection signal S102 having the quadrature component by the quadrature detection signal S111 having the in-phase component, and outputs a signal S141. Multiplier 150 multiplies quadrature detection signal S101 having the in-phase component and quadrature detection signal S111 having the in-phase component, and outputs signal S151. The sign inverter 160 receives the signal S151 output from the multiplier 150, inverts the sign, and outputs a signal S161. The subtracter 170 subtracts the signal S141 output from the multiplier 140 from the signal S161 output from the sign inverter 160, and outputs a dividend signal S171. The subtracter 180 subtracts the signal S131 output from the multiplier 130 from the signal S141 output from the multiplier 140, and outputs a divisor signal S181. Here, the generation route of the divisor signal S181 is the same as the generation route of the first embodiment. Therefore, the equation (181) indicating the divisor signal S181 is the same as that in the first embodiment.

[Example 2 / Signal]
Next, signals in the SSB signal receiving device 1-2 shown in FIG. 4 will be described. The expressions (911), (912), (61), (71), (101), (102), (111), (112), and (181) described in the first embodiment are the same in the second embodiment. This is because the signals of these equations have the same generation route as in the first embodiment.

In the second embodiment, the dividend signal S171 of the divider 190 is (171-2) = − (101) × (111) − (102) × (111) = {− (101) − (102)} × (111 ), It is expressed by the following formula.

In the second embodiment, since the amplification degree G = 1 of the phase shifter 50 and the phase shift amount φ = −π / 2, when these are substituted into the equations (171-2) and (181), the following equations are obtained. It is represented by

Therefore, the demodulated signal S191 output from the divider 190 is (191-2) = (171-2 ′) ÷ (181-2 ′), and is expressed by the following equation.

  Here, the equation (191-2) indicating the demodulated signal S191 is the same as the equation (191-1) indicating the demodulated signal S191 of the first embodiment. Thereby, it can be seen that the component of the baseband signal g (t) before modulation is obtained from the demodulated signal S191, as in the first embodiment. It can also be seen that an accurate SSB signal demodulated signal can be obtained without using amplitude information.

  By the way, in order that the divisor signal S181 does not become zero, (181) ≠ 0 is necessary. Since the equation (181) is the same as that in the first embodiment, the condition is represented by the above-described equation (900). In the case of the second embodiment, since G = 1 and φ = −π / 2, A / B> √2.

  As described above, according to the SSB signal receiving device 1-2 of the second embodiment, when the amplification degree G = 1 and the phase shift amount φ = −π / 2, which are the design values, are set. The amplitude ratio adjuster of the noise removal circuit 900 is set so that the ratio of the maximum amplitude A of the carrier wave component S911 and the maximum amplitude B of the SSB signal component S912, which is an output signal of the noise removal circuit 900, satisfies the condition of Expression (900). By setting the amplification factor of the amplifiers 910 and 920 or the attenuation factor of the attenuator, the divisor signal S181 of the divider 190 does not become zero in any case. Therefore, since the demodulated signal S191 that is the output signal of the divider 190 does not become indefinite in any case, it is possible to demodulate the original signal more accurately than before, and to remove audible noise.

  Further, according to the SSB signal receiving device 1-2 of the second embodiment, since the phase shift amount φ = −π / 2, the right side of the equation (900) is minimized. As a result, A / B can be reduced as compared with other phase shift amounts, so that the amplitude of the demodulated signal S191 can be increased (see equation (191-2)). Therefore, in the process using the demodulated signal S191, the signal-to-noise power ratio can be increased.

Example 3
Next, Example 3 will be described. The third embodiment is a generalization of the first and second embodiments described above. In the phase shifter 50 provided in the carrier wave / signal recombining circuit 80, an arbitrary amplification degree G is set, and the phase shift is performed. In this example, the amount φ is set in the range of −2π <φ ≦ 0 (where φ ≠ −π, 0). This Example 3 includes Example 1 and Example 2. FIG. 5 is a diagram showing the configuration of the SSB signal receiving apparatus (Example 3) according to the embodiment of the present invention.

  First, the configuration of the SSB signal receiving device 1-3 will be described. The SSB signal receiving apparatus 1-3 includes a frequency conversion circuit 20, a carrier wave / signal separation circuit 30, an amplifier 40, a noise removal circuit 900, a carrier wave / signal resynthesis circuit 80, quadrature detection circuits 100 and 110, and a detection signal calculation circuit 200. −3 and a divider 190. The noise removal circuit 900 includes amplitude ratio adjusters 910 and 920, the carrier wave / signal recombination circuit 80 includes a phase shifter 50 and combiners 60 and 70, and the quadrature detection circuit 100 includes a phase shifter 101. , Multipliers 102 and 103 and LPFs 104 and 105, quadrature detection circuit 110 includes phase shifter 111, multipliers 112 and 113, and LPFs 114 and 115, and detection signal calculation circuit 200-3 includes multipliers 130 and 140. 150, amplifiers 152 and 154, an adder 156, and subtracters 170 and 180.

  When comparing the SSB signal receivers 1-1 and 1-2 of the first and second embodiments shown in FIGS. 3 and 4 with the SSB signal receiver 1-3 of the third embodiment shown in FIG. Are the same, but the detection signal calculation circuit 200-3 of the SSB signal reception device 1-3 is different from the detection signal calculation circuit 200-1 of the SSB signal reception device 1-1 and the SSB signal reception device 1-2. The difference is that the configuration of the detection signal arithmetic circuit 200-2 is generalized. Hereinafter, in FIG. 5, the same reference numerals are given to portions common to FIGS. 3 and 4, and detailed description thereof will be omitted. The phase shifter 50 of the carrier wave / signal recombining circuit 80 amplifies the carrier wave component S911 by the amplification degree G, shifts the phase by the phase shift amount φ, and outputs the carrier wave component S51. In this case, the carrier wave component S911 and the carrier wave component S51 are signals having different signs, amplitudes, or phase shifts by the phase shifter 50.

  In FIG. 5, the noise removal circuit 900 inputs the carrier wave component S41 amplified by the amplifier 40 and the SSB signal component S32 separated by the carrier wave / signal separation circuit 30 so that the divisor signal S181 does not become zero. The carrier wave component S32 and the carrier wave component S41 are amplified or attenuated so as to meet the condition of the expression (900) described above, and the carrier wave component S911 and the SSB signal component S912 are output. It is the same.

  Further, the detection signal calculation circuit 200-3 receives the quadrature detection signal S101 and quadrature detection signal S102 of the in-phase component from the quadrature detection circuit 100, and the quadrature detection signal S111 and quadrature component of the quadrature detection circuit 110. The quadrature detection signal S112 is input, a predetermined calculation is performed, and a dividend signal S171 and a divisor signal S181 for obtaining a demodulated signal S191 are output. Specifically, the multiplier 130 multiplies the quadrature detection signal S101 having the in-phase component and the quadrature detection signal S112 having the quadrature component, and outputs a signal S131. The multiplier 140 multiplies the quadrature detection signal S102 having the quadrature component by the quadrature detection signal S111 having the in-phase component, and outputs a signal S141. Multiplier 150 multiplies quadrature detection signal S101 having the in-phase component and quadrature detection signal S111 having the in-phase component, and outputs signal S151. The amplifier 152 receives the signal S151 output from the multiplier 150 and multiplies the signal S151 by sinφ. The amplifier 154 receives the signal S131 output from the multiplier 130 and multiplies the signal S131 by cos φ. The adder 156 adds the signal multiplied by the amplifier 152 and the signal multiplied by the amplifier 154, and outputs a signal S157. The subtracter 170 subtracts the signal S141 output from the multiplier 140 from the signal S157 output from the adder 156, and outputs a dividend signal S171. The subtracter 180 subtracts the signal S131 output from the multiplier 130 from the signal S141 output from the multiplier 140, and outputs a divisor signal S181.

  In the case of the first embodiment, since the phase shift amount φ = −3π / 2, sin φ = 1 in the amplifier 152 and cos φ = 0 in the amplifier 154. Therefore, the configuration of the detection signal arithmetic circuit 200-3 is the same as that of the detection signal arithmetic circuit 200-1 shown in FIG. In the second embodiment, since the phase shift amount φ = −π / 2, sin φ = −1 in the amplifier 152 and cos φ = 0 in the amplifier 154. Therefore, the configuration of the detection signal calculation circuit 200-3 is the same as the configuration of the detection signal calculation circuit 200-2 shown in FIG.

  In FIG. 5, since the generation route of the divisor signal S181 is the same as the generation route of the first and second embodiments, the equation (181) indicating the divisor signal S181 is the same as that of the first and second embodiments. . Therefore, in order that the divisor signal S181 does not become zero, (181) ≠ 0 is necessary, and the condition is expressed by the above-described equation (900). When phase shift amount φ is −2π <φ ≦ 0 and φ = −π or 0, equation (900) does not have a solution, so that the SSB signal receiving device 1-3 does not remove noise. Can not.

  Further, as described in the first and second embodiments, the demodulated signal S191 is generated in the same manner, so that the component of the baseband signal g (t) before modulation can be obtained and the amplitude information is used. Therefore, an accurate demodulated signal of the SSB signal can be obtained. A description of the equation for generating the demodulated signal S191 is omitted.

  As described above, according to the SSB signal receiving apparatus 1-3 of the third embodiment, when the amplification degree G and the phase shift amount φ of the phase shifter 50 that are the design values are set, the output of the noise removal circuit 900 The amplitude ratio adjusters 910 and 920 of the noise removal circuit 900 are adjusted so that the ratio of the maximum amplitude A of the carrier wave component S911 and the maximum amplitude B of the SSB signal component S912 matches the condition of the equation (900). By setting the amplification level or the attenuation level of the attenuator, the divisor signal S181 of the divider 190 does not become zero in any case. Therefore, since the demodulated signal S191 that is the output signal of the divider 190 does not become indefinite in any case, it is possible to demodulate the original signal more accurately than before, and to remove audible noise.

  In any of the first to third embodiments described above, the amplitude ratio adjusters 910 and 920 included in the noise removal circuit 900 are amplifiers when the amplification degree is greater than 1, and the amplification degree is 1 When it is smaller, it is an attenuator. Omitting an amplifier or attenuator is the same as setting the amplification degree of the amplifier or attenuator to 1.

  The present invention has been described with reference to the embodiments. However, the present invention is not limited to the first to third embodiments, and various modifications can be made without departing from the technical idea thereof.

  In the first to third embodiments, the SSB signal receiving apparatuses 1-1 to 1-3 are configured by the circuits shown in FIGS. 3 to 5, but the present invention is not necessarily configured by hardware. However, a part or all of them are configured by a DSP (Digital Signal Processor) or CPU (Central Processing Unit) and a storage device, and a program for realizing a part or all of the functions is stored in the storage device. Also good. In this case, the function is realized by causing the DSP or CPU to execute a program stored in the storage device.

It is a figure which shows the structure of the conventional SSB signal receiver. It is a figure for demonstrating the SSB signal receiver of this invention. It is a figure which shows the structure of the SSB signal receiver (Example 1) by embodiment of this invention. It is a figure which shows the structure of the SSB signal receiver (Example 2) by embodiment of this invention. It is a figure which shows the structure of the SSB signal receiver (Example 3) by embodiment of this invention. It is a wave form diagram of the demodulated signal by the conventional SSB signal receiver. It is a wave form diagram of the demodulation signal by the SSB signal receiver (Example 1) by embodiment of this invention.

Explanation of symbols

1, 2 SSB signal receiver 20 Frequency conversion circuit 30 Carrier / signal separation circuit 40 Amplifier 50 Phase shifter 60, 70 Synthesizer 80 Carrier / signal recombination circuit 100, 110 Quadrature detection circuit 101, 111 Phase shifter 102, 103 , 112, 113 Multipliers 104, 105, 114, 115 LPF
130, 140, 150 Multiplier 152, 154 Amplifier 156 Adder 160 Sign inverter 170, 180 Subtractor 190 Divider 200 Detection signal operation circuit 900 Noise removal circuit 910, 920 Amplitude ratio adjuster

Claims (4)

In an SSB signal receiving apparatus that demodulates an SSB signal to which a carrier wave is added by quadrature detection,
A carrier wave / signal separating means for separating the SSB signal to which the carrier wave is added into a carrier wave component and an SSB signal component;
Amplitude adjusting means for adjusting the maximum amplitude based on the carrier component and the SSB signal component;
The carrier wave component and the SSB signal component with the maximum amplitude adjusted are input, the carrier wave component and the SSB signal component are combined, a carrier wave component having a different code, amplitude, or phase is generated from the carrier wave component, and the generated carrier wave A carrier wave / signal combining means for combining the component and the SSB signal component and outputting these two combined signals;
Orthogonal detection means for orthogonally detecting the two combined signals and outputting an orthogonal detection signal;
A detection signal calculation means for generating a demodulated signal of the SSB signal by a division calculation using the quadrature detection signal output by the quadrature detection means,
An SSB signal receiving apparatus characterized in that the divisor in the division operation of the detection signal calculating means does not become zero by adjusting the maximum amplitude of the carrier wave component and the SSB signal component by the amplitude adjusting means. The SSB signal receiving device according to claim 1,
The carrier wave / signal combining means has a phase shifter for generating carrier wave components having different signs, amplitudes or phases;
The amplitude adjusting unit is configured such that the maximum amplitude of the carrier component after amplitude adjustment is A, the maximum amplitude of the SSB signal component after amplitude adjustment is B, the amplification degree of the phase shifter is G, and the phase shift amount is φ. ,

The SSB signal receiving apparatus is characterized in that the maximum amplitude of the carrier wave component and the maximum amplitude of the SSB signal component are adjusted so as to satisfy the above condition. The SSB signal receiving device according to claim 2,
The SSB signal receiving apparatus characterized in that the phase shift amount φ of the phase shifter is set to -3π / 2 or -π / 2. The SSB signal receiving device according to claim 2,
The SSB signal receiving apparatus characterized in that the phase shift amount φ of the phase shifter is set to −2π <φ ≦ 0 (where φ ≠ −π, 0).

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