JPH01248765A - Receiving machine - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a receiver that receives signals transmitted by both sideband and vestigial sideband methods in AM modulation, and particularly for automotive applications where ghost flutter suddenly changes. The present invention relates to a receiver suitable for TV reception, etc.

[Conventional technology]

Image quality deterioration due to ghost flutter on TV and transmission has recently become a problem as buildings become taller. In particular, with in-vehicle TV receivers, the reception environment for radio waves is poor, and measures against fading are taken by diversity reception using antenna switching to prevent image quality deterioration. However, there is a long-awaited system that can quickly respond to changes in ghosts.

Traditional ghost detection technology
B, 2, pp. 157-163, 1984,
Journal of Television Television Society, 40.9, pp. 892-8
98 pages, 1986, Journal of the Television Television Society, 40.1
1. 5, as discussed in pages 1098 to 1105, 1986, by separating the synchronization signal from the video signal and detecting the timing of the rise of this synchronization signal, the Boost constant < mts ratio r , delay time τ, and high frequency phase angle ψ), and the operation timings of various detection circuits, arithmetic circuits, etc. are all generated from synchronization signals.

[Problem to be solved by the invention]

The above conventional technology has the problem that it is not possible to generate accurate timing signals to various circuits due to disturbances in synchronization timing due to rapidly changing ghosts and collapse of synchronization signals due to multiple long ghosts, and the ghost detection circuit malfunctions. Ta.

SUMMARY OF THE INVENTION An object of the present invention is to provide a receiver having a ghost constant detection section capable of detecting a ghost constant for any ghost K and having a function of reducing the influence of ghost interference.

[Means to solve the problem]

The above purpose is to provide a ghost detection circuit with a means for detecting an IF multiplied signal AM, an A-D converter that samples the AM detection output for a fixed period at an arbitrary timing, and a Fourier transform of the sampling data to obtain the frequency spectrum of the signal. A Fourier transform unit for detection and an arithmetic circuit that detects a ghost constant by using the fact that the amplitude and phase of the upper side wave component and residual side wave component or lower side wave component of the signal are equal or have a constant relationship from the frequency spectrum. This is achieved by configuring.

[Effect]

The AM detection means detects the in-phase and quadrature components of the IP multiplied signal, and the A-D converter outputs the AM detection for a certain period of time at any timing not directly related to the multiplexed timing signals such as synchronization signals and pilot signals. The Fourier transform unit performs Fourier transform on the sampling data to detect the frequency spectrum, and the arithmetic circuit operates to calculate the ghost constant from the frequency spectrum at any timing, so it can detect rapidly changing ghosts and multiple long Even if the synchronization signal or pilot signal is corrupted by a ghost or the like, the ghost constant can be detected without malfunction.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing a ghost detection circuit according to an embodiment of the present invention.

The configuration and operating principle of the same figure (&) will be explained below.

1 is a ghost detection circuit section, 2 is an IF signal input terminal, 3 is a synchronous detection circuit, 4 is a synchronous detection circuit, 5 is a phase synchronized oscillator, 6 is an A-D converter, 7 is an A-D converter, 8 is a 90° phase shifter, 9 is an arithmetic circuit section, 10 is a Fourier transform section, 11 is a Fourier transform section, 12 is an arithmetic circuit, 15 is a control voltage generation circuit, and 42 is a detection circuit section.

The IF multiplied signal input to terminal 2 is input to synchronous detection circuits 3 and 4, and is 90° with respect to the oscillation signal from the phase synchronous oscillator.
The oscillation signal whose phase is shifted by 0° by the phase shifter 8 is subjected to in-phase and quadrature detection. The in-phase and quadrature detection outputs from the synchronous detection circuits 3 and 4 are sampled at arbitrary timings for a certain period of time by human converters 6 and 7, and the in-phase and quadrature detection outputs with respect to the time axis are converted into discrete value data, and each is subjected to Fourier transformation. Fourier transform is performed by sections 10 and 11. The operation so far will be described in more detail.

If we assume that the IF multiplied signal input to terminal 2 is the IF multiplied signal of TV broadcast using the vestigial sideband (VSB) method, the input signal If(t) is Ir(t) −a(t) + X ui( t)
−= (1) Ghost wave arriving via the path g(
t) is the modulation signal, γ1 is the amplitude ratio of the desired wave and ghost wave,
τ1 is the delay time of the ghost wave, ψ1 is the phase angle of the ghost wave with respect to the desired wave, and ωO is the IF multiplied signal angular frequency.

The residual sideband signal spectrum is shown as shown in Figure 2 (&), and the roll-off characteristic of the vSB filter is shown as shown in (1)). For example, the characteristic W(ω) of the VSB filter is W(ω)−5,7(
-β≦ω≦β) (3), and the Fourier transform of the modulation signal g(t) is G(ω), h.

If we express the Fourier transform of (1) by H(ω), then H(ω)−
G(ω)·W(ω) There is a relationship shown in (4).

The input signal Ir(t) shown in equation (1) is all(ωot
-ψ), the outputs q(t) and 1(t) of the synchronous detection circuits 3 and 4 are q(t) -g(t)-ψ-h(t)mψ+2γtg(
t-τ1)as e i-Σrih(t-rt)s+n
θ1 1(t) −−g(t) ginψ−h(t) cr11ψ
-Jrtg(t-τ1)-01-Σr1h(t-τ1)
■θ1...-(s) (θ1--ψ1+ψ) Output Q(ω) of the Fourier transform sections 10 and 11.

! (ω) is ω, and the discrete value data for ω in (6) is input to the arithmetic circuit 12%C. The operation of the arithmetic circuit 12 will be explained below. The signal data input to the arithmetic circuit 12 is the real part and imaginary part of the above equation (6), and the respective components are Q, -(ω), Qi(ω).
).

Ir(ω), 11(ω), and the angular frequency −β to β
If you extrude only the range of Qr(6))-6Gr(ω) + b-Gi(ω)
−・・・−(7)Qi(ω)=−b−Qr(ω
) + α−Ql(ca+) −・−(8)Ir
(ω)-o-Gr(ω)+a-G1(ω)
−−−・−(9)11(ω)−−4−Qr(ω)
+a−Gi(ω) ・<10). By the way, the signal spectra A and B shown in Fig. 2 (α) are ω-
Since there is a symmetrical angular frequency position (±ωe)K with O as the center, the spectral components of the modulated signal are equally spectrum A,
The ratio A/B of B is given by a relational expression using only ghost constants. Spectra A and B are expressed by the ratio of A and B, and in the case of a single ghost, if three angular frequency points in the range -β≦ω≦β are pushed out, (12)
Five equations shown in the formula can be made simultaneously, and the three unknowns, that is, the Siborst constants (r, τ, φ) can be calculated. In addition, if there are ghost waves of 2 waves, 3 waves, etc., the boost constant can be detected by pushing out the angular frequency points by 6 points, 9 points, etc., respectively. The ghost constant detected by the arithmetic circuit 12 is sent to the control voltage generation circuit 15, where it controls various circuits such as a TV receiver, such as a circuit for ghost elimination, a transversal filter, etc. Generate and output voltage.

As described above, according to this embodiment, the boost constant can be detected by sampling the AM detection signal for a certain period of time at an arbitrary timing. ), the ghost constant can be detected under any ghost conditions because it is not affected by timing signals such as synchronization signals and pilot signals multiplexed with the signal, improving ghost detection performance.

Furthermore, if the sampling period of the A-D converters 6 and 7 is set to the same horizontal interval, approximately 65 to 49μ flags or more, a horizontal synchronizing signal always exists within that sampling period. Ghosts can be detected even at the white level.If the horizontal synchronization signal is included, there is a double harmonic of the horizontal synchronization signal of 15.75KH, and the frequency spectrum sampled in this way has only a limited number of frequencies. Therefore, simultaneous equations can be easily created and ghost constant detection can be speeded up.

Although this embodiment has been described with respect to TV broadcast waves of the vestigial sideband system, the same operation can be performed for broadcast waves having other AMm harmonic signals including those of the double sideband system. In particular, the QPSK method and the QPSK method, which put video and audio signals into orthogonal components and transmit more information within a limited band, are strongly affected by ghosts (reflected waves), so this method's ghost detection method is effective. It is.

An embodiment of the present invention shown in FIG. 1 (1) will be described below.

Blocks that perform the same operations as those shown in FIG. 1(a) are given the same numbers.

In the figure (b), 14 is a bandpass filter that extracts a part of the upper sideband, 15 is a bandpass filter that extracts a part of the residual sideband, and 16 and 17 are envelope detection circuits. The IF multiplied signal inputted to the terminal 2 is branched, and one side is inputted to the bandpass filter 14 and the other side is inputted to the bandpass filter 15. The bandpass filters 14 and 15 operate to extract signal components in the band A shown by the solid line and the band B shown by the dashed line from among the bands shown by the broken line in FIG.
4 extracts the signal component of the band A portion, and a bandpass filter 15 extracts the signal component of the band B portion. The signals that have passed through each bandpass filter are envelope-detected by envelope detection circuits 16 and 17, and the detection power of each is sampled at arbitrary timing for a certain period of time by A-D converters 6 and 7, and converted into discrete value data. do. This discrete value data is subjected to Fourier transform by Fourier transform sections 10 and 11, respectively, and the frequency spectrum of the signal after envelope detection is detected, and each data is input to an arithmetic circuit 12. In the arithmetic circuit 12, the svector person is obtained from the Fourier coefficient output of the Fourier transform section 10, the svector B is obtained from the output of the Fourier transform section 11, and the ratio of the two is calculated as #) (12) A similar equation is obtained. From this, the ghost constant can be detected in the same way as the principle explained in the embodiment of FIG. 1 (α).

According to this embodiment, the same effect as that described in the explanation of the embodiment of FIG.
Since the outputs of 0 and 11 themselves represent the frequency spectrum that appears in the upper sideband, the residual sideband, or the frequency spectrum that appears in the lower sideband, processing in the arithmetic circuit 12 is simplified and ghost detection is Speed-up can be achieved.

Note that the bandpass filters 14 and 15 are required to have steep cutoff characteristics, but can be constructed from SAW filters, digital filters, or the like.

An embodiment of the present invention shown in FIG. 1(0)K will be described below.

Note that blocks that operate in the same way as in FIG. 1 (α) are given the same numbers.

In the same figure (0), 18 is a ghost detection circuit section by digital signal processing, 19 is an RF signal input terminal, 20 is a frequency conversion circuit section, 21 is a terminal to which the IF multiplied signal orthogonal component is output or input, 22.23 is a mixer, 24 is a local oscillator, 25 is a 90° phase shifter, 26 and 27 are digital filters that split the input data into the two bands A and B shown in FIG. 2 (Q), 2B, 29, 30
and 51 is a squaring circuit that squares input data, 32 and 63 are adder circuits, and 54 and 35 are high-speed A-D converters that sample the in-phase component and quadrature component of the IF multiplied signal for a certain period of time at an arbitrary timing and discretize the same. It is a vessel.

The RF multiplied signal inputted to the terminal 19 is branched into two, one is frequency-converted by the oscillation signal from the local oscillator 24 in the mixer 22 and becomes the IF multiplied signal in-phase component, and the other is split into the 90° phase shifter 25 in the mixer 25. The frequency is converted by the oscillation signal that has passed through the oscillation signal, and it becomes an IP multiplied signal orthogonal component. High speed A
-D converters 34 and 65 perform AD conversion on the IP multiplied signal in-phase component and quadrature component, and digital filters 26 and 27 separate the components into band A and band B. I
Among the in-phase components of the F signal, the data of the signal components that can pass through the band A are sent to the 2-east circuit 28, and among the in-phase components of the IF signal, the data of the signal components that can pass through the band Bi are sent to the 2-east circuit 3.
0, data of signal components that can pass through band A among the orthogonal components of the IP signal are sent to the 2 East circuit 29.

Among the IF signal orthogonal components, data of signal components that can pass through band B are inputted to the 2nd east circuit 31 and squared.
Addition circuits 32 and 33 add the signals.

The outputs of the adder circuits 52 and 55 are subjected to Fourier transform by calculating the square root thereof in Fourier transform units 10 and 11 to detect a frequency spectrum and send the data to the calculation circuit 12. The data input to the arithmetic circuit is equal to the above equations (13) and (14), and the ghost constant can be calculated by similarly setting up simultaneous equations using (15).

As described above, this embodiment has the same effects as the embodiments shown in FIGS. 1(a) and 1(b).

As above, the embodiment of FIG. Further, in the case of FIG. 1(0), it can also be constructed with a digital signal processing processor.

Hereinafter, a third embodiment of a ghost processing circuit using the ghost detection circuit units 1 and 18 according to an embodiment of the present invention will be described.
This will be explained with reference to FIGS.

FIG. 3 is a block diagram showing a ghost processing circuit according to an embodiment of the present invention. FIG. 3 (α) shows the case where the ghost detection circuit 1 is used, and FIG. This is an example. 56 is an IF band signal processing circuit operated by an external control signal, and detects ghost constants (γ11τ1.ψ1) from ghost detection circuit units 1 and 18.
A feedback type detection control system is constructed by controlling the signal processing circuit 36. The signal processing circuit 36 has two
The function of the entire circuit differs depending on the function of the circuit. One of them is that the signal processing circuit 36 can be made into a ghost removal circuit by configuring a filter with reverse characteristics of the transmission path using a transversal filter or the like and making it an erasure circuit. The other is to perform simple waveform shaping and equalization by generating a reverse phase signal of the ghost wave component of the IF signal input to terminal 2 and adding the reverse phase signal. It is possible to carry out operations to assist synchronization separation in (stages), operations of means for generating timing signals to various circuits, or to prevent malfunctions.

As described above, in this embodiment, by using the signal processing circuit 56 as an erasing circuit, it is possible to remove the boost, and by assisting the operation of the means for generating the timing signal, it is possible to prevent synchronization errors and to prevent timing errors in the receiver. This has the effect of preventing malfunctions of various circuits that require signals.

FIG. 4 is a block diagram showing a ghost processing circuit according to an embodiment of the present invention, and 57 is a delay device.

Similarly to FIG. 5, this embodiment also includes a signal processing circuit 36 for processing ghost waves in the IF signal band, and constitutes a feed-forward type detection control system.

The figure (α) # (1)) shows an embodiment using the ghost detection circuit section 1, and the figure (0) and (d) show the embodiment using the ghost detection circuit section 18t.

Figures (b) and (d) show a multi-processing effect by correcting the delay time of the arithmetic processing time of the boost detection circuit sections 1 and 18 by configuring a delay device 57 in the detection control loop. It is an enhanced version of In this example, the third
Similar to the embodiment shown in the figure, the signal processing circuit 36 is controlled by control signals from the ghost detection circuit section 1 and 1, and cancels ghosts as a ghost removal circuit, or assists the operation of the timing signal generation means in the subsequent stage. By doing so, you can expect the same effect as Ro.

FIG. 5 is a block diagram showing a ghost processing circuit according to an embodiment of the present invention, and 38 is a video detection circuit section for detecting an IF signal. This embodiment is an example in which the signal processing circuit 36 is configured in the video stage, and (α) is an example in which the ghost detection circuit 1 is used, and (b) is an example in which the ghost detection circuit 18 is used to configure the ghost processing circuit. In this embodiment as well, as described in the explanation of the embodiment in FIG. By providing assistance, we can expect the same effect as Mr. Ro.

An embodiment of the ghost processing circuit shown in FIGS. 3 to 5 has been described above, but the signal processing circuit 56 may function as a ghost removal circuit that completely eliminates ghosts, or may function as a means for generating a timing signal in the subsequent stage. As described above, when used as a ghost removal circuit, in addition to configuring an inverse filter using the detection ghost constant to eliminate it, for example, the amplitude ratio γ1 of the detection constant
Ghost removal is also possible by treating rl as one control signal and sequentially using an adaptive algorithm to operate adaptively so that the value of rl becomes zero. For example, this is a method in which the amplitude ratio r1 is converged to a reference value of zero by applying the maximum slope method or the like and modifying the tap coefficients of the successive transversal filter.

Furthermore, when the timing signal generating means is used as a correction circuit, detection accuracy and erasure accuracy sufficient to remove ghosts are not required, and the circuit can be configured with a simple hardware circuit. For example, if the signal processing circuit 360 input signal is delayed or advanced by τ1 according to the detection delay time τ1, and an inverse phase signal is generated and added, processing to the extent that the synchronization signal can be separated is performed. The timing signals sent to various circuits can be accurately captured.

A timing regeneration method for preventing synchronization signal corruption due to ghosts and synchronization timing malfunctions due to sudden changes in ghosts will be described below.

FIG. 6 is a block diagram showing one method of timing regeneration for providing timing signals to various circuits of a receiver using the ghost detection circuit sections 1 and 18 of the present invention.

59 is a synchronization separation circuit that separates a synchronization signal from a video signal, and 40 is a timing generation circuit section that generates a timing signal. The same figure (α) shows the ghost detection circuit section 1, the same figure (
1)) is a configuration example when the ghost detection circuit section 18 is used.

The video signal detected by the video detection circuit section 58 is input to a synchronization separation circuit section 59, where the synchronization signal is separated. What is shown in FIG. 7(α) is the extracted synchronization signal.

The timing generation circuit section 40 receives this synchronization signal and the detected ghost constant, and considers the signal with the largest amplitude among the υ direct wave and the ghost wave as the desired wave. For example, in Figure 7 (α
), the signal shown by the broken line is determined to be the desired wave, and in the case of 1ffb), the signal shown by the - dotted chain line is determined to be the desired wave. In the state of (α) in the figure, a synchronization timing signal is generated when the synchronization signal rises or falls. In the following state, when the signal level of the dot-dashed line increases rapidly as shown in (b) in the same figure, the signal with the maximum amplitude ratio γ1 of the detected ghost constant is used as the desired wave, and the synchronization signal rises or falls. A timing signal as shown in FIG. 3(d) is generated by setting the rising edge of the timing signal at a timing shifted by the detection delay time τ1 at that time.

As described above, according to the present embodiment, it is possible to prevent synchronization disturbance due to a sudden change in ghost, and also to prevent and improve the deterioration of the DU ratio of the signal since the signal with the maximum amplitude is used as the desired wave.

FIG. 8 is a block diagram showing one method of timing generation for giving timing signals to various circuits of a receiver using the ghost detection circuit units 1 and 18 of the present invention, and (α) in the figure shows a method for generating timing for providing timing signals to various circuits of a receiver. The circuit section 1 shown in FIG. 2B is an example configured using a ghost detection circuit 18. Reference numeral 41 denotes a variable delay device controlled by a control signal containing information on the ghost detection circuit section 1 and the detected ghost constant from the first day. FIG. 10 shows a synchronization signal, with the dotted line representing a direct wave and the dashed line representing a ghost wave.

In FIG. 8, the synchronization signal of the signal detected by the video detection circuit section 58 is such that a direct wave rises at time t1 shown in FIG. If the signal is larger, then this signal is delayed by τ′ by the variable delay device 41, and the rise of the direct wave is in the time portion, and the timing generation circuit portion 40
The rising edge of time ti is determined by the control signal from the ghost detection circuit section 1 or 18 and the output from the synchronization separation circuit section 59, and a timing signal is generated and output. FIG. 10(b) shows the synchronizing signal portion of the output signal of the variable delay device 41. The state of the ghost suddenly changes from this state, and the state where the ghost wave level becomes higher than the direct wave level is the synchronization signal shown in FIG. 10(c). The ghost detection circuit section 38 that has detected all of this state uses the variable delay device 41 to set the high-level ghost wave as the desired wave.
is operated to reduce the amount of delay by the detected delay time τ, thereby obtaining the synchronizing signal waveform shown in FIG. 10 (4). As a result, the timing signal generation circuit section 40 generates a timing signal at the same timing as in the initial state, and the entire receiver circuit can handle the ghost wave as a desired wave, thereby preventing synchronization disturbance. Furthermore, even if the synchronization signal is corrupted, the ghost detection circuit units 1 and 18 can detect the ghost constant, so by holding the timing generation circuit 40 at the initial timing and controlling the variable delay device 41, the timing signal can be regenerated in the same way. can.

As described above, according to this embodiment, even if the synchronization separation circuit section 59 cannot perform normal synchronization separation, the ghost detection circuits 1 and 18 can control the variable delay device 41 and the timing generation circuit section 40. can be reproduced, malfunctions of various circuits can be prevented, and DU ratio deterioration can be prevented by selecting the desired wave.

The embodiment shown in FIG. 9 is the variable delay device 41 in FIG.
is configured in the IF stage, and can perform the same operation as the embodiment shown in Figure 8. Furthermore, since the processing is in the IP signal band, it is possible to provide timing signals to various circuits in subsequent stages. This increases the effectiveness of preventing malfunctions. Above 9th
According to the embodiments shown in FIGS. 1 and 10, it is possible to prevent synchronization disturbances due to sudden changes in ghosts and malfunctions of various circuits due to this.

All of the embodiments described above are based on the vestigial sideband method.
It is applicable to receivers used in broadcasting and communications using double-sideband systems, and detects constants such as reflected waves, ghost waves, and echoes that occur in transmission systems such as wireless and wired cables, and uses the detection constants to detect Since the signal processing is carried out using the following signals, the operation speed of the series of signal processing for the goth) K is high.

FIG. 11 is a diagram showing the configuration of a space diversity receiver using the ghost detection circuit section 1 according to an embodiment of the present invention. Blocks that operate in the same way as in the previous embodiment are given the same numbers. In the figure, 43 and 44 are antennas, and 45 and 46 are RF
A frequency converter for converting the double signal to the IP double signal; 47 is a local oscillation circuit; 48 is a changeover switch for switching and selecting the outputs from the frequency converters 45 and 46 under external control;
Reference numeral 49 denotes a level detection circuit section which inputs the signal from the changeover switch 48 and detects the level of the input signal at the timing from the timing generation circuit section 40.

This embodiment relates to a receiver that performs antenna switching diversity reception using one of the timing signal regeneration configurations shown in FIG. 8(α), and its operation will be described below.

The changeover switch 48 selects either the antenna 46 and the frequency converter 46 or the antenna 44 and the frequency converter 45 in the initial state. Suppose that the timing generation circuit unit 40 reproduces a timing signal of, for example, a TV double signal vertical synchronization signal, and sends this to the level detection circuit unit 49.
The level detection circuit detects the level of the output signal from one of the receiving systems using this timing signal, and selects the changeover switch 4.
8, detects the level of the output signal from the other receiving system, compares the two levels, selects the one with the higher level, and controls the selector switch 48 to select the receiving system with the higher level. do.

According to this embodiment, the timing generation circuit section 40 generates accurate timing signals regardless of the presence or absence of ghosts, so that antenna switching and level detection operations do not malfunction, allowing accurate signal reception and synchronization. Disturbance can be prevented.

FIG. 12 is a block diagram showing the configuration of a space dipacity receiver using a ghost detection circuit section 1t according to an embodiment of the present invention. numbered and shown. The operation will be described below.

The signal processing circuit 56 is a circuit that performs signal processing at the IF stage, and is a transversal filter that eliminates ghosts using the ghost constant from the ghost detection circuit section 1. As in the embodiment shown in FIG. 11, one of the reception systems is selected by the changeover switch 48, and one IF multiplied signal passes through the signal processing circuit 36 and is detected by the video detection circuit section 3B.
9 is input. One is input to the ghost detection circuit section 1 to detect a ghost constant, and this constant is sent to the signal processing circuit 36 and the timing generation circuit 40. The timing generation circuit section 40 generates an accurate timing signal using the synchronization signal from the synchronization separation circuit section and the ghost constant, and sends the timing signal to the level detection circuit section 49 . On the other hand, the signal processing circuit 36 processes ghosts regardless of the timing signal, and from the output thereof, the level detection circuit 49
The same operation as in the embodiment shown in the figure is performed. However, selector switch 4
Since the ghost constant changes when switching the antenna, the level detection circuit section 49 sends a reset signal to the signal processing circuit 56 so as to reset the tap coefficient of the transversal filter in the signal processing circuit 56 when switching the antenna.

As described above, antenna switching and level detection operations do not malfunction due to ghosts, and operate to select a receiving system with a high level, and operate to remove ghosts by the signal processing circuit 36, so fading and ghost interference are avoided. 13 is a block diagram showing the configuration of a space diversity receiver using the ghost detection circuit section 1 according to an embodiment of the present invention, which is similar to the embodiment described above. Blocks that perform the following actions are given the same number. In the figure, reference numeral 51 denotes a phase synthesis chainer which converts the RF multiplied signal received by the antennas 43 and 44 into the IF multiplied signal, combines the carrier phases of both signals, and outputs the resultant signal.

The IF multiplied signal, which is the output of the phase synthesizer 50, is inputted to the demodulation circuit 51 and the ghost detection circuit section 1 via the signal processing circuit 56. A ghost constant is detected in the ghost detection circuit section 1, the signal processing circuit 36 is controlled, and the ghost is removed in the signal processing circuit 56. The phase synthesis chainer 50 always operates to synthesize carrier phases into the same phase regardless of external timing signals, and the ghost detection circuit section 1 also operates regardless of external timing signals.

According to this embodiment, the phase synthesis tuner 50 enables stable reception that is resistant to fading, and the signal processing circuit 36 eliminates ghost interference, thereby improving reception quality. Further, according to this embodiment, the phase synthesis themeer 50
The ghost detection circuit unit 1 can be operated independently without external timing control, and it is not limited to TV signals that include timing signals such as synchronization signals, but can be transmitted in the vestigial sideband or both sidebands. Diversity reception in which signals can be processed becomes possible.

The embodiments described above can be applied not only to TV signals but also to receivers for broadcast communication using the vestigial sideband method or the double sideband method, and can perform effective processing.

〔Effect of the invention〕

According to the present invention, in a receiver used for broadcasting or communication using a vestigial sideband method or a double sideband method, it is possible to detect a constant of a reflected wave (ghost wave) from a signal spectrum,
This makes it possible to construct a receiver that can reproduce corrupted timing signals and the like included in multiple signals and also remove reflected waves, which has the effect of eliminating reception disturbances caused by reflected waves.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a ghost detection circuit according to an embodiment of the present invention, FIG. 2 is a signal spectrum diagram representing a residual sideband, and FIGS. 3, 4, and 5 are an embodiment of the present invention. A block diagram showing the example ghost processing circuit, FIG. 6 is a block diagram showing one method for generating all the timing signals according to an embodiment of the present invention, and FIG. 7 is a signal waveform showing the synchronization signal and the generated timing signal. 8 and 9 are diagrams representing one method for generating timing signals according to an embodiment of the present invention; FIG. 10 is a timing diagram representing synchronization and timing signals; FIGS. FIG. 13 is a block diagram showing a space diversity receiver according to an embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Ghost detection circuit part, 18... Ghost detection circuit part, 3, 4... Synchronous detection circuit, 9... Arithmetic circuit, 10, 11... Fourier transform part, 12... Arithmetic operation Circuit, 14゜15... Bandpass filter, 16, 17.
... Envelope m-ray detection circuit, 26, 27... Digital filter, 56... Signal processing circuit, 40... Timing generation circuit section, 41... Variable delay device, 42... Detection circuit section. Representative Patent Attorney Katsutoshi Ogawa / [ (b) Hayabusa I Figure (Q) 2nd (OL) (e) Figure 3 (α) 4th - Figure 5 (b) 6th (b) ) 77th (cL) (b) (C) (CL) Time → Saketoshima 8th face (OL) (b) /d ↑U ’7th Cb’) 1st θ Ward

Claims (1)

[Claims] 1. Receive signals transmitted in the double sideband method and the vestigial sideband method, and receive a first signal in an upper sideband higher than the carrier wave and a lower sideband or vestigial side lower than the carrier wave. A detection circuit section that detects a second signal in the wave band, and the amplitude ratio, delay time, and high frequency phase of the direct wave that arrives directly from the transmission point via the transmission path and the reflected wave that arrives through a different transmission path. an arithmetic circuit unit that calculates and detects a reflected wave constant such as an angle from the first and second signals; and a control signal that is generated and output from the reflected wave constant detected by the arithmetic circuit unit to a means for processing an external received signal. 1. A receiver comprising a control voltage generation circuit. 2. The receiver according to claim 1, wherein the detection circuit section includes a first synchronous detection circuit that performs in-phase synchronous detection of the received signal and a second detection circuit that performs orthogonal detection of the received signal. . 3. The detection circuit section includes a first synchronous detection circuit that performs in-phase synchronous detection of the received signal, and a second synchronous detection circuit that performs orthogonal synchronous detection of the received signal.
The detection outputs of the synchronous detection circuit and the first synchronous detection circuit are A
- A first A-D converter that performs D conversion, and a second A-D converter that performs A-D conversion of the detection output of the second synchronous detection circuit. Receiving machine. 4. The arithmetic circuit unit includes a first Fourier transform unit that inputs the first signal and performs Fourier transform, a second Fourier transform unit that inputs the second signal and performs Fourier transform, and a first
2. The receiver according to claim 1, further comprising an arithmetic circuit that calculates a reflected wave constant from the output of the Fourier transform section and the output of the second Fourier transform section. 5. The arithmetic circuit unit includes a first Fourier transform unit that performs Fourier transform on the output of the first AD converter, and a first Fourier transform unit that performs Fourier transform on the output of the first AD converter;
A second Fourier transform unit that Fourier transforms the output of the A-D converter, and an arithmetic circuit that calculates a reflected wave constant from the output of the first Fourier transform unit and the output of the second Fourier transform unit. The receiver according to claim 1, characterized in that: 6. The arithmetic circuit unit performs Fourier transform on the output data of the first A-D converter and the output data of the second A-D converter, and calculates a reflected wave constant from the data obtained by the Fourier transform. 2. The receiver according to claim 1, further comprising a microcomputer that performs calculation and output processing. 7. The detection circuit unit includes a first bandpass filter that extracts the first signal from the received signal, and a first bandpass filter that extracts the first signal from the received signal.
a second bandpass filter that extracts a signal from the first bandpass filter; a first envelope detection circuit that envelope-detects a signal passed through the first bandpass filter; and a second envelope detection circuit that envelope-detects a signal passed through the second bandpass filter. 2. The receiver according to claim 1, characterized in that it is constituted by a line detection circuit. 8. The detection circuit section includes a first bandpass filter that extracts the first signal from the received signal, and a first bandpass filter that extracts the first signal from the received signal.
a second bandpass filter for extracting the signal of an envelope detection circuit, a first A-D converter that converts the output of the first envelope detection circuit from analog to digital, and a second A-D converter that converts the output of the second envelope detection circuit from analog to digital. 2. The receiver according to claim 1, wherein the receiver comprises a -D converter. 9. The arithmetic circuit unit includes a first Fourier transform unit that performs Fourier transform on the output of the first AD converter, and a first Fourier transform unit that performs Fourier transform on the output of the first AD converter;
A second Fourier transform section that Fourier transforms the output of the A-D converter, and an arithmetic circuit that calculates a reflected wave constant from the output of the first Fourier transform section and the output of the second Fourier transform section. The receiver according to claim 1, characterized in that: 10. The arithmetic circuit section performs a Fourier transform on the output data of the first A-D converter and the output data of the second A-D converter, and calculates a reflected wave constant from the data obtained by the Fourier transform. 2. The receiver according to claim 1, comprising a microcomputer that performs calculation and output processing.