CN202077057U - High-precision recovery device for single side-band carriers - Google Patents

Abstract

The utility model provides a high-precision recovery device for single side-band carriers. A single side-band signal is inputted through the input end of a two power divider; the output end of the two power divider is connected with a first detector circuit and the input end of an automatic gain control circuit respectively; the output end of the first detector circuit is connected with the contort end of the automatic gain control circuit; a differential circuit, a second detector circuit, a blocking circuit, a proportional amplifier circuit and a first adder circuit are connected in sequence behind the output end of the automatic gain control circuit; a bias voltage is inputted through the other input end of the first adder circuit; a voltage-controlled oscillator, a frequency mixer and a band pass filter are connected in sequence behind the output end of the first adder circuit; the other input end of the frequency mixer is connected with the automatic gain control circuit; the output end of the band pass filter and the output end of the voltage-controlled oscillator are connected with two input ends of a second adder circuit respectively; and the output end of the second adder circuit serves as the output end of the recovery device. The high-precision recovery device has the advantages that carrier signals in the single side-band signal can be recovered without distortion, and the structure is simple.

Description

A kind of high accuracy recovery device of single sideband singal carrier wave

Technical field

The utility model belongs to communicator, is specifically related to a kind of carrier resetting device of single sideband singal.

Background technology

Coherent demodulation all has remarkable advantages at aspects such as the error rate, detection threshold and output signal-to-noise ratios than non-coherent demodulation, and the purpose that carrier wave recovers is in order to realize coherent demodulation and parameter measurement at receiving terminal.

Carrier wave for the signal of communication that contains carrier component recovers to adopt the phase locked track ring to realize usually, and it is relatively easy that carrier wave recovers; For digital modulation signals, the estimating carrier frequencies algorithm and the carrier recovering method of various maturations such as existing quadratic loop, four directions ring and improved form thereof; And for the modulated-analog signal of suppressed carrier, as: FM (frequency modulation, Frequency Modulation), SSB (monolateral band, Single Side-Band), DSB (double-side band, Double Side-Band) signal such as, the carrier spectrum component of these signals is suppressed at transmitting terminal, and receiving terminal will carry out carrier wave and recover relatively difficulty.

In existing communication system, measurement to the single sideband singal carrier frequency is to adopt single sideband singal spectrum estimation approach, its certainty of measurement is to change with the variation that modulated-analog signal is composed, the gained measurement result is not the carrier frequency on the practical significance, yet there are no the report of relevant single sideband singal carrier frequency accurate measurement method and device so far.

The utility model content

Technical problem to be solved in the utility model be in the existing communication system to the low problem of single sideband singal carrier frequency certainty of measurement, and provide a kind of high accuracy recovery device of single sideband singal carrier wave.

In order to solve the problems of the technologies described above, the technical solution adopted in the utility model is: a kind of high accuracy recovery device of single sideband singal carrier wave, comprise two power splitters, first detecting circuit, automatic gain control circuit, differential circuit, second detecting circuit, block isolating circuit, the ratio amplifying circuit, first add circuit, voltage controlled oscillator, frequency mixer, band pass filter, and second add circuit, the input input single sideband singal of described two power splitters, output is connected respectively to the input of first detecting circuit and automatic gain control circuit, the output of described first detecting circuit is connected to the control end of automatic gain control circuit, be connected with differential circuit in turn behind the output of described automatic gain control circuit, second detecting circuit, block isolating circuit, the ratio amplifying circuit, first add circuit, the straight partially voltage of another input input of first add circuit, connect voltage controlled oscillator behind the output of first add circuit successively, frequency mixer, band pass filter, another input of described frequency mixer is connected to automatic gain control circuit, the output of band pass filter and the output of voltage controlled oscillator are connected respectively to two inputs of second add circuit, and the output of second add circuit is as the output of this recovery device.

Advantage of the present utility model is: the utility model device provides a kind of realization that recovers based on the single sideband singal carrier wave that removes amplitude modulation(PAM) and signal reconstruction, solve the difficult problem that the single sideband singal carrier frequency is accurately measured, recovered the carrier signal in the single sideband singal undistortedly.This device is simple, has the engineering realizability.

Description of drawings

Fig. 1 is the composition frame chart of the high accuracy recovery device of a kind of single sideband singal carrier wave of the utility model.

Fig. 2 is the flow chart of the carrier recovering method of the single sideband singal of use the utility model realization.

Embodiment

Single sideband singal is a kind of signal of communication of carrier suppressed, does not have independently carrier component in signal.Single sideband singal has the characteristics of amplitude modulation-phase-modulated signal, and its envelope changes with the envelope value of modulation signal, and phase place changes with the instantaneous phase of modulation signal, has the advantages that the frequency spectrum linearity is moved.

See also shown in Figure 1ly, the high accuracy recovery device of a kind of single sideband singal carrier wave of the utility model comprises first module 1, second module 2, three module 3, and four module 4.

Described first module 1 comprises two power splitters 101, detecting circuit 102, automatic gain control (AGC) circuit 103, described second module 2 comprises differential circuit 201 and detecting circuit 202, described three module 3 comprises block isolating circuit 301, ratio amplifying circuit 302, add circuit 303, and voltage controlled oscillator 304, described four module 4 comprises frequency mixer 401, band pass filter 402, and add circuit 403.

The input input single sideband singal of described two power splitters 101, output is connected respectively to the input of detecting circuit 102 and automatic gain control circuit 103, the output of described detecting circuit 102 is connected to the control end of automatic gain control circuit 103, be connected with differential circuit 201 behind the output of described automatic gain control circuit 103 in turn, detecting circuit 202, block isolating circuit 301, ratio amplifying circuit 302, add circuit 303, the straight partially voltage of another input input of add circuit 303, connect voltage controlled oscillator 304 behind the output of add circuit 303 successively, frequency mixer 401, band pass filter 402, another input of described frequency mixer 401 is connected to automatic gain control circuit 103, the output of the output of band pass filter 402 and voltage controlled oscillator 304 is connected respectively to two inputs of add circuit 403, and the output of add circuit 403 is as the output of this recovery device.

1 pair of single sideband singal that receives of described first module carries out detection to be handled, and utilizes detection information that single sideband singal is carried out automatic gain and handles, and removes the am signals on the single sideband singal, makes single sideband singal become the phase-modulated signal of standard.

Described second module 2 is carried out differential to this phase-modulated signal and is handled, and handles the instantaneous angular frequency information that extracts this phase-modulated signal by detection again.

Described three module 3 goes out a new phase-modulated signal according to the instantaneous angular frequency signal reconstruct, and the phase-modulated signal of reconstruct is that carrier frequency and amplitude are different with having removed the phase-modulated signal that obtains behind the am signals, and further feature is identical.

Described four module 4, with the phase-modulated signal that reconstructs with removed the phase-modulated signal that obtains behind the am signals and carried out Frequency mixing processing, signal after the mixing is carried out bandpass filtering treatment, leach difference frequency signal wherein, the standard phase-modulated signal that the frequency of difference frequency signal and part 1 are produced carries out phase place and adds processing, can draw the frequency of the carrier signal of single sideband singal, thereby recover the carrier wave of single sideband singal.

Please consult Fig. 2 simultaneously, the operation principle and the process of the high accuracy recovery device of a kind of single sideband singal carrier wave of the utility model are as described below.

Single sideband singal is imported into and is divided into two-way by two power splitters 101 behind the equipment, and one the road to detecting circuit 102, detects the size of input signal.Another road is to automatic gain control circuit 103, and this circuit core device is a slice VGA device, the voltage control that this device is produced by detecting circuit 102, so the signal of automatic gain control circuit 103 outputs is phase-modulated signal S of a weighing apparatus envelope ₁(t).S ₁(t)＝A _mcos[ω _ct+φ(t)]

S ₁(t) phase-modulated signal enters differential circuit 201, this phase-modulated signal is carried out differential handle, and extracts the instantaneous angular frequency information of this phase-modulated signal again by detecting circuit 202.To S ₁(t) phase-modulated signal carries out the differential processing, can get:

$S_2\left(t\right)=A_m{K}_d({\mathrm{\ω}}_c+\frac{\mathrm{d\φ}\left(t\right)}{\mathrm{dt}})\cos [{\mathrm{\ω}}_{c}t+\mathrm{\φ}\left(t\right)]$

In the formula, K _dBe discriminator sensitivity, unit is V/rad/s.

To S ₂(t) detection is handled, and can get:

$S_3\left(t\right)=A_m{K}_d{K}_0({\mathrm{\ω}}_c+\frac{\mathrm{d\φ}\left(t\right)}{\mathrm{dt}})$

In the formula, K ₀Be the envelope detection voltage transmission coefficient.S ₃(t) comprised instantaneous angular frequency information.

With S ₃(t) signal can get through block isolating circuit 301 and ratio amplifying circuit 302:

$S_5\left(t\right)=A_m{K}_d{K}_0{K}_p\frac{\mathrm{d\φ}\left(t\right)}{\mathrm{dt}}$

In the formula, K _pBe the ratio gain amplifier.K _pIt is the problem of inconsistency that is used to compensate the modulation sensitivity of front end discriminator sensitivity, envelope detection voltage transmission coefficient and rear end VCO (voltage controlled oscillator, Voltage Controlled Oscillator).

With S ₅(t) signal and a constant inclined to one side direct voltage V _b(V _bValue be VCO frequency of oscillation center control voltage) in add circuit 303, carry out addition and handle, and with addition result S ₆(t) be loaded into the tuning end of voltage controlled oscillator device 304, this moment, the instantaneous angular frequency of voltage controlled oscillator device 304 output signals can be expressed as:

S ₇(t)＝A _vco?cos[2πf ₁t+φ(t)+φ _v]

In the formula, f ₁For added voltage on the tuning end of voltage controlled oscillator 304 is D _bPairing frequency during volt that is to say the frequency of carrier signal of the phase-modulated signal that reconstructs.

With the phase-modulated signal S that reconstructs ₇(t) the phase-modulated signal S that produces with auto-gain circuit 103 ₁(t) carry out Frequency mixing processing, this function finishes 401 by frequency mixer 401, can obtain mixer output signal:

$S_8\left(t\right)=\frac{1}{2}{A}_m{A}_{\mathrm{vco}}\cos [2\mathrm{\π}(f_c-f_1)t+{\mathrm{\φ}}_v]+\frac{1}{2}{A}_m{A}_{\mathrm{vco}}\cos [2\mathrm{\π}(f_1+f_c)t+2\mathrm{\φ}\left(t\right)+{\mathrm{\φ}}_v]$

Wherein, f _cCarrier frequency for former single sideband singal.

With the signal S after the mixing ₈(t) in band pass filter 402, carry out bandpass filtering treatment, leach difference frequency signal wherein:

$S_9\left(t\right)=\frac{1}{2}{A}_m{A}_{\mathrm{vco}}\cos [2\mathrm{\π}(f_c-f_1)t+{\mathrm{\φ}}_v]$

Add circuit 403 is with the frequency f of difference frequency signal _c-f ₁Carrier frequency f with the phase-modulated signal of reconstruct ₁Carry out addition and handle, can draw the frequency of the carrier signal of single sideband singal, thereby recover the carrier wave of single sideband singal.

Device of the present utility model provides a kind of and has recovered realization equipment based on the single sideband singal carrier wave that removes amplitude modulation(PAM) and signal reconstruction, has solved the difficult problem that the single sideband singal carrier frequency is accurately measured, the undistorted carrier wave that recovers single sideband singal.This device workflow is simple, has practical value.

Claims (1)

1. the high accuracy recovery device of a single sideband singal carrier wave, it is characterized in that: comprise two power splitters, first detecting circuit, automatic gain control circuit, differential circuit, second detecting circuit, block isolating circuit, the ratio amplifying circuit, first add circuit, voltage controlled oscillator, frequency mixer, band pass filter, and second add circuit, the input input single sideband singal of described two power splitters, output is connected respectively to the input of first detecting circuit and automatic gain control circuit, the output of described first detecting circuit is connected to the control end of automatic gain control circuit, be connected with differential circuit in turn behind the output of described automatic gain control circuit, second detecting circuit, block isolating circuit, the ratio amplifying circuit, first add circuit, the straight partially voltage of another input input of first add circuit, connect voltage controlled oscillator behind the output of first add circuit successively, frequency mixer, band pass filter, another input of described frequency mixer is connected to automatic gain control circuit, the output of band pass filter and the output of voltage controlled oscillator are connected respectively to two inputs of second add circuit, and the output of second add circuit is as the output of this recovery device.

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