JPH0831821B2 - Electric field measurement circuit - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric field measuring circuit for measuring an input electric field level in a band of a receiver, and more particularly to an electric field measuring circuit for measuring an input electric field level of a received signal of a mobile telephone system which requires high speed electric field measurement. Regarding the circuit.

[0002]

2. Description of the Related Art A base station of a conventional mobile telephone system such as an automatic telephone is equipped with an electric field measuring circuit for measuring an electric field of a radio signal coming from a communication partner and performing optimum exchange control ( (See Japanese Patent Laid-Open No. 61-139127).

FIG. 6 is a block diagram showing a conventional example of an electric field measuring circuit.

In FIG. 6 , the first local section 220 is
A voltage control transmission unit (hereinafter referred to as VCO) 221, an amplification unit 222, a frequency divider / phase comparator (programmable counter) 224, a low-pass filter (hereinafter referred to as LPF) 22.
5 and a reference signal generating circuit 223 (PLh (Ph
It is a synthesizer of the as Locked Loop system and outputs a local signal S222 . Amplifier 10
4, the first mixer 105, the first intermediate frequency amplifier (hereinafter,
It is referred to as the first IF unit. ) 106, the second local unit 107,
The electric field level detection unit 108, the second mixer unit 109, and the demodulation unit 110 form a super-heterodyne reception unit that measures the input electric field level of the received signal according to the frequency of the local signal. The first local unit 220 generates a local signal S222 having a frequency according to the channel designation signal S211 from the control unit 211, and the first mixer unit 105.
Supply to. The first mixer unit 105 converts the reception signal S103 amplified by the amplification unit 104 into a first intermediate frequency signal (hereinafter, referred to as a first IF signal) S105, and supplies it to the first IF unit 106. In the first IF section 106, the first IF signal S105 is amplified and supplied to the second mixer section 109 and also to the electric field level detection section 108.
The second mixer unit 109 converts the second local signal S107 from the second local unit 107 into a second intermediate frequency signal (hereinafter referred to as a second IF signal) S109, demodulates it in the demodulation unit 110, and demodulates the demodulated data. S110 to control section 211
Send to. The electric field level detection unit 108 detects the input electric field level and sends it to the control unit 211 as electric field information S108.

[0005]

In the above-described conventional electric field measuring circuit, the frequency of the local signal is determined by the channel designation signal from the control unit 211.
It takes several tens of msec to receive the channel designation signal from 11 and settle to the desired frequency, and the control unit determines the frequency according to the command from the host station. , Band 10
There is a drawback in that the measurement time becomes extremely long when trying to measure all 400 channels in the case of MHz) and real-time measurement cannot be performed.

An object of the present invention is to provide an electric field measuring circuit capable of measuring an electric field at high speed.

[0007]

An electric field measuring circuit of the present invention receives a received signal according to a local signal output from a PLL type synthesizer and a PLL type synthesizer when high-speed electric field measurement is not performed, When performing a high-speed electric field measurement, the loop of the PLL of the synthesizer is released, a local signal of a desired frequency is generated by a preset voltage, and a switching circuit for receiving a received signal according to the local signal is provided. Have.

The electric field measuring circuit of the present invention has a control section for outputting a channel designating signal, a voltage controlled oscillating section and a phase comparator, and receives a channel designating signal output from the control section to generate a local signal. A PLL-type synthesizer for outputting a signal, a superheterodyne-type receiver for measuring an input electric field level of a received signal according to the frequency of the local signal, and means for outputting a selection signal and a switching signal provided in the controller. , By the selection signal,
An internal control signal generating circuit for generating a control voltage and a switching circuit for releasing the connection between the phase comparator and the voltage controlled oscillator of the PLL loop by the switching signal and supplying the control voltage to the voltage controlled oscillator. Have and. Preferably, the receiving unit measures an input electric field level of a reception signal of the mobile telephone system.

[0009]

The electric field measuring circuit of the present invention receives a channel designation signal from the control unit, and is a known PL including a VCO, an amplifying unit, a frequency divider, a phase comparator, an LPF and a reference signal generating circuit.
In the electric field measuring circuit which receives the local signal from the L-type synthesizer and detects the received input electric field which is input to the receiver according to the frequency of this local signal, the channel designation signal from the control unit is changed by the switching signal from the control unit. It has a function of generating the output frequency of the VCO according to the output voltage from the internal control signal generating circuit without receiving it. Therefore, when measuring the electric field distribution in the band at high speed, by releasing the PLL loop and measuring it, the sending time for channel designation and the lock time of the synthesizer can be omitted, so that the electric field distribution can be measured at high speed in a very short time. Can be measured.

[0010]

Embodiments of the present invention will now be described with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a graph showing a relationship between a VCO control voltage and a local signal frequency, and FIG. 3 is a graph showing an output example of an internal control signal generating circuit. 4 is a graph showing an output example of the internal control signal generating circuit, and FIG. 5 is a graph showing an example of electric field level measurement.

In FIG. 1, the first local unit 120 is
VCO 121, amplifier 122, frequency divider / phase comparator 12
4, a PLL type synthesizer including an LPF 125 and a reference signal generating circuit 123, and a local signal S1.
22 is output. Similarly to the conventional example shown in FIG.
4, first mixer section 105, first IF section 106, second local section 107, electric field level detection section 108, second mixer section 109 and demodulation section 110 measure the input electric field level of the received signal according to the frequency of the local signal. It constitutes a super-heterodyne receiver.

When high-speed electric field measurement is not performed, the first local section 120 is similar to the conventional example shown in FIG.
A local signal S122 having a frequency according to the channel designation signal S111 from 11 is generated and supplied to the first mixer unit 105. In the first mixer section 105, the reception signal S103 amplified by the amplification section 104 is converted into the first IF signal S105.
And is supplied to the first IF unit 106. First IF unit 1
At 06, the first IF signal S105 is amplified and supplied to the second mixer unit 109 and also to the electric field level detection unit 108. The second mixer unit 109 receives the second IF signal by the second local signal S107 from the second local unit 107.
The signal S109 is converted, demodulated by the demodulator 110, and demodulated data S110 is sent to the controller 111. The electric field level detection unit 108 detects the input electric field level and sends it as electric field information S108 to the control unit 111.

On the other hand, when performing high-speed electric field measurement, the switching circuit 126 is switched by the switching signal S129 from the control unit 111.
And the control voltage S127 supplied to the VCO 121 is generated from the internal control signal generation circuit 127. As a result, the PLL loop is released and the internal control signal generation circuit 1
The control signal S127 from the local signal S12
The frequency of 2 is determined. The control voltage S127 can generate a VCO control voltage S125 having a correlation with the oscillation frequency, as shown in FIG.

Switching between high-speed electric field measurement and normal electric field measurement
The replacement is controlled and controlled by the control unit 111. Control
The controller 111 controls the electric power detected by the electric field level detector 108.
The boundary information S108 is predetermined by a conventional method.
Compare with the standard value. The detected electric field level is
When not exceed the reference value, the control unit 111, an internal control
The signal generation circuit 127 and the switching circuit 126 are respectively
Controlled by selection signal S128 and switching signal S129
Then, high-speed electric field measurement is performed. And the detected electric field
Once the level exceeds the reference value, the control unit 111
It controls the control signal generation circuit 127 and the switching circuit 126.
Then, a normal electric field measurement is performed. At the beginning of the electric field measurement,
Perform fast electric field measurements.

3 and 4 show an internal control signal generating circuit.
Wave of VCO control voltage S125 generated by 127
The example of the figure is shown. Figure 3 shows the sweep waveform
4 shows a random search waveform. Either of FIG. 3 or FIG.
Also in the case, the range of VCO control voltage S125 generated
Corresponds to the frequency band assigned to the system
I do. In FIG. 3, the VCO control voltage S125 is changed from the minimum value to the maximum value.
An example of linearly changing to a large value is shown. Figure 4 shows the waveform
Amplitude decreases over time and eventually falls to a desired value.
An example of bundling is shown. FIG. 5 shows the local signal S122.
Indicates the detected voltage level with respect to the frequency of
The electric field distribution curve of is shown. Electric field distribution curve in Figure 5
Is the VCO control voltage S12 having the sweep waveform shown in FIG.
By using 5, it can be easily obtained.

Further, if there is a channel that causes a problem after measuring the electric field distribution, it is possible to specify a channel signal as in the conventional case and perform a detailed measurement. When an interfering wave or the like occurs within the own system band, the conventional measurement can be performed. By using the circuit of this embodiment having both the function and the high-speed measurement function, the analysis can be performed very efficiently in a short time.

[0018]

As described above, according to the present invention, when the electric field distribution in the band is measured at high speed, the PLL loop is released to perform the measurement, whereby the transmission time for channel designation and the lock time of the synthesizer can be omitted. Therefore, there is an effect that the measurement can be performed at high speed in a very short time.

[Brief description of drawings]

FIG. 1 is a block diagram showing one embodiment of the present invention.

FIG. 2 is a graph showing the relationship between VCO control voltage and local signal frequency.

FIG. 3 is a graph showing an output example of an internal control signal generation circuit.

FIG. 4 is a graph showing an output example of an internal control signal generation circuit.

FIG. 5 is a graph showing an example of electric field level measurement.

FIG. 6 is a block diagram showing a conventional example of an electric field measurement circuit.

[Explanation of symbols]

 104 amplification section 105 first mixer section 106 first IF section 107 second local section 108 electric field level detection section 109 second mixer section 110 demodulation section 111 control section 120 first local section 121 VCO 122 amplification section 123 reference signal generation circuit 124 minutes Frequency / Phase comparator 125 LPF 126 Switching circuit 127 Internal control signal generation circuit

Claims (3)

[Claims] 1. A PLL type synthesizer, and when high-speed electric field measurement is not performed, a reception signal is received according to a local signal output from the PLL type synthesizer, and when high-speed electric field measurement is performed, the synthesizer of the synthesizer is used. In the electric field measuring circuit having a switching circuit for releasing a loop of the PLL to generate a local signal having a desired frequency by a preset voltage and receiving a received signal according to the local signal , the preset voltage But the amplitude over time
Characterized by a decreasing random search waveform,
Electric field measurement circuit. 2. A control unit for outputting a channel designation signal,
A voltage controlled oscillator and an output frequency of the voltage controlled oscillator,
The output of the voltage control is compared with the frequency of the reference signal.
A phase comparator that returns to the oscillating unit is provided , and receives the channel specifying signal output from the control unit and receives the channel specifying signal as a pair.
An electric field measuring circuit having a PLL-type synthesizer for outputting a local signal having a corresponding frequency and a superheterodyne-type receiving unit for measuring an input electric field level of a received signal according to the frequency of the local signal, wherein the control unit is provided. Measured by the receiver
If the electric field level is lower than a predetermined standard, the first logic
The level selection signal and the switching signal of the first logic level
The electric field level measured by the receiver is output.
A selection signal of the second logic level when the value exceeds a predetermined standard
And means for outputting a switching signal of the second logic level , and voltage control when the selection signal is the first logic level.
The output frequency of the oscillator scans the entire range of the specified frequency band.
An internal control signal generating circuit for generating a control voltage for the voltage controlled oscillator , and the phase when the switching signal is at the first logic level.
By disconnecting the connection between the comparator and the voltage controlled oscillator,
Connect the output of the internal control signal generation circuit to the voltage controlled oscillator.
If the switching signal is at the second logic level,
The voltage controlled oscillator and the output of the internal control signal generation circuit
And disconnecting the connection between the phase comparator and the voltage controlled oscillator
Possess a switching circuit which connects the, the initial time of the electric field measurement, the selection signal and the switching of the control unit
The means for outputting the replacement signal is a selection signal of the first logic level.
And outputting a switching signal of the first logic level.
Electric field measurement circuit to collect. 3. The electric field measuring circuit according to claim 2, wherein the receiving unit measures an input electric field level of a reception signal of the mobile telephone system.