JP2002009639A - Digital wireless transmission fpu device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a ground wireless relay unit having high accuracy and high frequency stability with which can supply IF signals from a remote place. SOLUTION: An IF signal generating section 12 supplies a digitally modulated IF signal 30 to a transmission control section IF amplifier 22, which amplifies the IF signal 30 and superimposes a reference signal 23, from a reference signal generating section 13 to the IF signal 30 to obtain an IF signal 22a, and outputs the resulting signal to a transmission high-frequency section IF amplifier 20 via an IF cable 24 as an IF signal 22a. The IF amplifier 20 extracts a reference signal 10 from the received IF signal 20a, supplies the reference signal 10 to a PLL circuit 9, receives a PLL output pilot signal 11 to obtain an IF signal 2a and to output it to an IF frequency converter 3. The IF frequency converter 3 mixes the signal 2a with an IF local oscillation signal 17a, a next-stage RF frequency converter 4 mixes the output of the converter 3 with an RF local oscillation signal 18a and gives an output 4a to a power amplifier 5. The PLL circuit 9 supplies the pilot signal 11 and TF/RF local oscillation signals, all of which satisfy required synchronization conditions with the reference signal 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-precision frequency-stabilized reference signal for a transmission signal, which is supplied to a transmission high-frequency section. And a digital radio transmission FPU device having a function of achieving high stability.

[0002]

2. Description of the Related Art Digital wireless transmission FP according to the prior art
FIG. 2 shows a block diagram of the U device.

In FIG. 2, reference numeral 12 denotes an IF signal generator for generating a digitally modulated IF signal 30a, 1 a transmission high-frequency unit for converting a required IF signal 30 into an RF signal 5a and sending it out, and 2 an IF signal. A transmission high-frequency IF amplifier for amplifying 30, an IF frequency converter 3 for converting the IF signal 2 a amplified to a predetermined level into a signal of a required frequency, and 4 a signal converted to a required frequency for a required RF signal An RF frequency converter 4a for converting the signal into 4a, a power amplifier 5 for power-amplifying and outputting the RF signal 4a input from the RF frequency converter 4, and 6 transmitting an RF signal 5a of a required level input from the power amplifier 5 An antenna 7 is an IF local oscillator that generates an IF local oscillation signal 7a input to the IF frequency converter 3, and an RF local oscillation signal 8 is input to the RF frequency converter 4. Shows the RF local oscillator for generating a.

Hereinafter, the operation will be described. The IF signal generation unit 12 generates a digitally modulated IF signal 30a and supplies the digitally modulated IF signal 30a to the transmission high-frequency unit IF amplifier 2 of the transmission high-frequency unit 1. The transmission high-frequency unit IF amplifier 2 amplifies the IF signal 30 to a predetermined level and outputs the signal to the IF frequency converter 3.

[0005] The IF frequency converter 3 includes a transmission high-frequency section IF.
The IF signal 2a of a predetermined level input from the amplifier 2 is
Using the IF local oscillation signal 7a output from the F local oscillator 7, the signal is converted into a signal of a required frequency.

[0006] The RF frequency converter 4 converts a signal of a predetermined level input from the IF frequency converter 3 into an RF local oscillator 8.
Required RF using the RF local oscillation signal 8a which is the output of
The signal is converted to a signal 4a.

[0007] The power amplifier 5 transmits to the antenna 6 an RF signal 5 a obtained by power-amplifying the RF signal 4 a input from the RF frequency converter 4 to a predetermined level.

[0008]

In the conventional digital radio transmission FPU device, the IF local oscillator and the RF local oscillator generate an IF local oscillation signal and an RF local oscillation signal which are synchronized with respective reference oscillation signal sources. . However, OFDM (Orthogonal Frequency Division Multi-Media) with a narrow carrier interval used in digital terrestrial broadcasting, etc.
(plexing, orthogonal frequency division multiplexing) In the signal transmission by the modulation method, each local oscillation signal needs more accurate frequency stability, and if the frequency of the IF signal and the RF signal is not synchronized, the carrier in the receiving system is required. There is a problem that erroneous detection occurs.

In addition, an IF signal generating unit, which is a source for generating an IF signal, must be installed adjacent to the transmitting high frequency unit.
There is a problem that it is not possible to alleviate the restriction on the installation location of the digital wireless transmission FPU device by supplying the IF signal from a remote place.

The present invention provides a high precision and high frequency stability R
It is an object of the present invention to provide a digital radio transmission FPU device capable of transmitting an F signal and supplying an IF signal from a remote place.

[0011]

In order to achieve the above object, a digital radio transmission FPU apparatus according to the present invention is provided with a reference signal generating section, wherein the IF local oscillation signal and the RF local oscillation signal are several digits higher in accuracy. A reference signal having a high frequency stability is generated, and a transmission control unit is provided. In this case, the reference signal is superimposed on the IF signal, amplified and supplied to a transmission high-frequency unit, and separated from the IF signal in the transmission high-frequency unit. An IF local PLL reference signal, an RF local PLL reference signal, and a pilot signal generated by a PLL circuit based on the extracted reference signal to synchronize the IF local oscillator and the RF local oscillator, and to provide a pilot signal serving as a reference signal for a reception system. The pilot signal is superimposed on the IF signal after the reference signal is separated and extracted from the IF signal supplied from the transmission control unit. .

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a digital radio transmission FPU device according to the present invention will be described.

FIG. 1 is a block diagram of a digital radio transmission FPU device according to one embodiment of the present invention.

In FIG. 1, reference numeral 19 denotes a required IF signal 20.
The transmission high-frequency unit 20 a converts the frequency of the signal a into an RF signal 5 a and transmits the RF signal 5 a. The transmission high-frequency unit IF amplifier 20 amplifies the IF signal 20 a and extracts the reference signal 10. The transmission high-frequency unit 3 amplifies the IF signal 2 a amplified to a predetermined level. IF to convert to frequency signal
The frequency converter 4 is an RF frequency converter that converts a signal converted to a required frequency into a required RF signal 4a, and 5 is an R frequency converter.
A power amplifier for power-amplifying and outputting the RF signal 4a input from the F-frequency converter 4; an antenna 6 for transmitting an RF signal 5a of a required level input from the power amplifier 5;
Reference numeral 7 denotes an IF local oscillator that generates an IF local oscillation signal 17a input to the IF frequency converter 3, reference numeral 18 denotes an RF local oscillator that generates an RF local oscillation signal 18a input to the RF frequency converter 4, and reference numeral 9 denotes a reference signal. 10, a PLL circuit 10 for generating an IF local PLL reference signal 9a and an RF local PLL reference signal 9b serving as reference signals for an IF local oscillator 17 and an RF local oscillator 18 and a pilot signal 11 serving as a reference for a receiving system. I in the transmission high-frequency section IF amplifier 20
A reference signal extracted from the F signal 20a, a transmission control unit 21 for supplying the IF signal 30 to the transmission high-frequency unit 19, and a transmission control unit 22 for amplifying a signal obtained by superimposing the reference signal 23 on the IF signal 30 to a required level The IF amplifier 13 is a reference signal generator that generates a reference signal 23 a having several orders of magnitude higher accuracy and higher frequency stability than the local oscillation signal of the transmission high frequency unit 19,
2 is a signal I for generating a digitally modulated IF signal 30a.
An F signal generation unit 24 is an IF cable for transmitting the IF signal 22a from the transmission control unit 21 to the transmission high frequency unit 19.

The operation will be described below. IF signal generator 1
2 generates a digitally modulated IF signal 30 a and supplies it to the transmission control IF amplifier 22 of the transmission control unit 21.
In the transmission control unit 21, the input IF signal 30 is amplified to a required level by the transmission control unit IF amplifier 22. The transmission control unit IF amplifier 22 superimposes the reference signal 23 supplied from the reference signal generation unit 13 on the IF signal 30 and amplifies it to a required level to produce an IF signal 22a.
4 to the transmission high-frequency section 19.

The transmission high-frequency IF amplifier 20 amplifies the input IF signal 20a to a required level, and amplifies the reference signal 1a.
0 is extracted, and a pilot signal 11 output from the PLL circuit 9 is superimposed and output to the IF frequency converter 3 as an IF signal 2a.

The IF frequency converter 3 includes an IF local oscillator 1
The IF signal 2a is converted into a signal of a required frequency using the IF local oscillation signal 17a of No. 7 and output to the RF frequency converter 4.

The RF frequency converter 4 includes the RF local oscillator 1
The signal of a required frequency from the IF frequency converter 3 is converted into an RF signal 4a using the RF local oscillation signal 18a of No. 8 and output to the power amplifier 5.

The power amplifier 5 power-amplifies the RF signal 4 a input from the RF frequency converter 4 to a signal of a required level and sends it to the antenna 6.

IF local oscillator 17 and RF local oscillator 18
Are synchronized with the IF local PLL reference signal 9a and the RF local PLL reference signal 9b output from the PLL circuit 9.
It outputs the F local oscillation signal 17a and the RF local oscillation signal 18a to the IF frequency converter 3 and the RF frequency converter 4, respectively.

The PLL circuit 9 includes a pilot signal 11 synchronized with a reference signal 10, an IF local oscillator 17 and an RF signal.
An IF local PLL reference signal 9a and an RF local PLL reference signal 9b to the local oscillator 18 are generated.

The pilot signal 11 is a signal synchronized with the reference signal 10. The transmission high-frequency IF amplifier 20 separates the reference signal 10 superimposed on the IF signal 20 a from the separated signal.
The signal is superimposed on the F signal and becomes a reference signal for the receiving system.

[0023]

According to the present invention, if the transmission control unit
A signal having a high accuracy and high frequency stability is superimposed on the signal and transmitted to the transmission high frequency section. The transmission high frequency section separates and extracts the reference signal from the IF signal again and supplies the same to the PLL circuit. A PLL circuit generates an IF local PLL reference signal, an RF local PLL reference signal, and a pilot signal to synchronize the local oscillation signals of the IF local oscillator and the RF local oscillator, and superimposes the pilot signal on the IF signal. And can output RF signals with high accuracy and high frequency stability.
Modulated wave transmission becomes possible.

In addition, since the IF signal generator, which is an IF signal source, can be separated from the transmission high-frequency unit by the transmission control unit via the IF cable, the restriction on the installation location of the transmission high-frequency unit is relaxed, and the final RF signal is located near the antenna. Since a signal can be output, the influence of disturbance is reduced, and high-quality signal wireless transmission becomes possible.

[Brief description of the drawings]

FIG. 1 is a digital wireless transmission FP according to an embodiment of the present invention.
Block diagram of U device

FIG. 2 is a block diagram of a digital radio transmission FPU device according to the prior art.

[Explanation of symbols]

1: transmission high-frequency unit 2: transmission high-frequency unit IF amplifier 3:
IF frequency converter, 4: RF frequency converter, 5: power amplifier, 6: antenna, 7: IF local oscillator, 8: RF local oscillator, 9: PLL circuit, 10, 23, 23a: reference signal, 11: pilot Signal, 12: IF signal generation unit,
13: Reference signal generator, 21: Transmission controller, 22: Transmission controller IF amplifier, 24: IF cable, 30, 30
a: IF signal, 17: IF local oscillator, 18: RF local oscillator, 19: transmission high frequency unit, 20: transmission high frequency unit IF
Amplifier, 2a, 20a, 22a: IF signal, 4a, 5
a: RF signal, 7a, 17a: IF local oscillation signal, 8
a, 18a: RF local oscillation signal, 9a: IF local PLL
Reference signal, 9b: RF local PLL reference signal

Claims (3)

[Claims] 1. A digitally modulated IF (Intermedi
rate (intermediate frequency) signal to RF (Radio Frequency)
(cy, radio frequency) Digital radio transmission FP that converts the frequency to a signal, amplifies the power to the required level, and sends out from the antenna
In a U (Field Pick-up Unit, terrestrial radio relay device) device, an IF signal generation unit for generating the IF signal, a reference signal generation unit, an IF signal generated from the IF signal generation unit, and the reference signal generation Receiving the reference signal generated from the
A transmission control unit for superimposing the reference signal on a signal; receiving an IF signal on which the reference signal supplied from the transmission control unit is superimposed; separating the IF signal into an IF signal and a reference signal; A digital radio transmission FPU device comprising: a transmission high-frequency unit for converting a signal into an RF signal with a local oscillation signal synchronized with the reference signal, amplifying the power, and transmitting the amplified signal from the antenna. 2. The digital radio transmission F according to claim 1,
In the PU device, the transmission high-frequency unit receives an IF signal on which the reference signal supplied from the transmission control unit is superimposed, separates the signal into an IF signal and a reference signal, and generates a reference signal of a reception system synchronized with the reference signal. A pilot signal (pilot) as a signal, an IF station PLL reference signal synchronized with the reference signal, and an RF local station P
A PLL (Phase-Locked Loop) circuit for generating an LL reference signal; and a transmission high-frequency IF amplifier having a function of superimposing the pilot signal on an IF signal from which the reference signal is separated and amplifying the pilot signal to a required level. An IF local oscillator that generates the IF local oscillation signal synchronized with the IF local PLL reference signal; and an RF local oscillator that generates the RF local oscillation signal synchronized with the RF local PLL reference signal generated by the PLL circuit An IF frequency converter that performs frequency conversion of an IF signal on which a pilot signal output from the transmission high-frequency unit IF amplifier is superimposed with the IF local oscillation signal; and an IF signal that is frequency-converted by the IF frequency converter. An RF frequency converter for converting the frequency of the RF local oscillation signal into an RF signal; A digital radio transmission FPU device, comprising: a power amplifier for transmitting. 3. The digital radio transmission F according to claim 1,
In the PU device, the transmission control unit receives an IF signal generated from the IF signal generation unit and a reference signal generated from the reference signal generation unit, and superimposes the reference signal on the IF signal.
A digital radio transmission FPU device comprising a transmission control unit IF amplifier having a function of amplifying an F signal to a required level and supplying the IF signal to the transmission high frequency unit via an IF cable.