JPH10142312A - High frequency receiver - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high frequency receiver which can secure accuracy for positioning operations by detecting when a C/N of signals of an intermediate frequency band is deteriorated thereby to cause a malfunction at the carrier regeneration time. SOLUTION: An output of a loop filter 7 of a carrier regenerator 5 is connected to a window comparator 13 via a low pass filter(LPF) 12, and one output of the window comparator 13 is connected to a judge device 15 via a delay part 14, while the other output is directly connected to the judge device 15. The judge device 15 compares both outputs and generates an agreement/ disagreement signal to a positioning operation part 10. The output signal from the judge device 15 is used as alarm information when the output of the carrier regenerator 15 malfunctions, thereby to calculate a position of a high frequency receiver. Even if a C/N of waves from a satellite is deteriorated, the positioning can be carried out normally with good accuracy.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-frequency receiver for a positioning device in which a user receives a radio wave from a satellite and calculates his / her own position.

[0002]

2. Description of the Related Art FIG. 6 is a block diagram of a conventional high frequency receiver. 1 is a receiving antenna, 2 is a frequency converter, 3 is a local oscillator, 4 is a data demodulator, 5 is a carrier regenerator,
6 is a phase comparator (PD), 7 is a loop filter, 8 is a voltage controlled oscillator (VCO), 9 is a Doppler amount calculator, 10
Denotes a positioning calculation unit, and 11 denotes an automatic frequency control (AFC) processing unit.

Next, the operation will be described. In this type of high-frequency receiver, a receiving antenna 1 receives a radio wave from a satellite, and a frequency converter 2 converts the frequency into an appropriate intermediate frequency band. One of the signals in the intermediate frequency band can obtain a demodulated signal by the data demodulator 4. This demodulated signal contains carrier frequency information transmitted by the satellite. This demodulated information is passed to the Doppler amount calculator 9. The other of the output signals of the intermediate frequency band reproduces a carrier by the carrier regenerator 5 using a synchronous detection method, measures the frequency, and passes the received frequency information from the high frequency receiver to the Doppler amount calculation unit 9. The Doppler amount calculation unit 9 calculates the Doppler amount from the demodulation information and the reception frequency information, and the positioning calculation unit 10 calculates the position of the high frequency receiver. Further, an automatic frequency control (AFC) operation is performed on the output signal of the carrier regenerator 5 to control the local oscillator 3 so that the carrier regenerator 5 operates optimally.

[0004]

However, in the above-mentioned conventional configuration, the C / N of the signal in the intermediate frequency band is deteriorated due to the deterioration of the C / N of the radio wave from the satellite, and a malfunction occurs in the carrier reproduction. For this reason, the amount of Doppler fluctuates extremely, the positioning accuracy cannot be obtained, and the positioning cannot be performed normally. In this type of high-frequency receiver, it is necessary to perform positioning normally even when the C / N of a radio wave from a satellite is deteriorated, and sufficient positioning accuracy is required.

Accordingly, the present invention solves the above problem by detecting when the C / N of the signal in the intermediate frequency band is degraded or malfunctions in the carrier reproduction, so that accuracy can be obtained in the positioning calculation. It is intended to provide a high-frequency receiver.

[0006]

According to the first aspect of the present invention, the output of the loop filter of the carrier regenerator is connected to a window comparator via a low-pass filter, and one of the outputs of the window comparator is connected via a delay unit. To the determiner, the other is connected to the arithmetic unit as it is, and has a determiner that compares the two and outputs a match / mismatch signal to the positioning arithmetic unit, and outputs the output signal of the determiner when the output of the carrier regenerator malfunctions. The positioning of the receiver is calculated as the alarm information.

According to a second aspect of the present invention, the output of the determiner is connected to the automatic frequency control processing section, and when the output of the carrier regenerator malfunctions, the output signal of the determiner is used as alarm information to automatically output the signal to the receiver. It was used for frequency control operation to track the satellite.

According to a third aspect of the present invention, the output signal of the determiner is connected to a visual display means via a driver to notify alarm information to a user using the high frequency receiver.

[0009]

According to the first aspect of the present invention, positioning can be performed normally and sufficient positioning accuracy can be obtained even when the C / N of a radio wave from a satellite is deteriorated.

According to the second aspect of the present invention, even when the C / N of the radio wave from the satellite deteriorates in a short time, the satellite can be tracked, the positioning can be performed normally, and a sufficient position can be obtained. The positioning accuracy can be obtained.

According to the third aspect of the present invention, the output of the determiner can be connected to the visual display means via the driver, and alarm information can be shown to the user using the high frequency receiver.

(Embodiment 1) FIG. 1 is a block diagram of a high-frequency receiver according to Embodiment 1 of the present invention, and FIG. 2 is a configuration diagram of a window comparator, a delay unit, and a decision unit of the high-frequency receiver. 3 is a waveform diagram of the high-frequency receiver. FIG.
, 1 is a receiving antenna, 2 is a frequency converter, 3 is a local oscillator, 4 is a data demodulator, 5 is a carrier regenerator,
6 is a phase comparator (PD), 7 is a loop filter, 8 is a voltage controlled oscillator (VCO), 9 is a Doppler amount calculator, 10
Is a positioning operation unit, 11 is an AFC processing unit, 12 is a low-pass filter (LPF), 13 is a window comparator,
4 is a delay unit, and 15 is a decision unit.

The receiving antenna 1 is connected to a frequency converter 2. One of the outputs of the frequency converter 2 is connected to the data demodulator 4 and the other is connected to the carrier regenerator 5. The output of the data demodulator 4 and the output of the carrier regenerator 5 are connected to a Doppler amount calculator 9, and the output of the Doppler amount calculator 9 is connected to a positioning calculator 10. Further, a low-pass filter (L
PF) 12 to a window comparator 13, one of the outputs of the window comparator 13 is sent to a decision unit 15 via a delay unit 14, and the other is outputted to a decision unit 15
, And the determiner 15 is connected to the positioning operation unit 10.

In FIG. 2, a window comparator 1
3 is a first comparator 18, a second comparator 1
9, an AND circuit 20. 21 and 22 are reference voltages (3V, 2V). The output of the AND circuit 20 is input to the delay unit 14 and the determinator 15. The delay unit 14 has a delay unit 1, a delay unit 2, and a delay unit 3, and is connected to the determination unit 15.

Next, the operation will be described. The radio wave from the satellite is received by the receiving antenna 1 and the frequency is converted to the intermediate frequency band by the frequency converter 2. One of the signals in the intermediate frequency band can obtain a demodulated signal by the data demodulator 4. This demodulated signal contains carrier frequency information transmitted by the satellite. This demodulated information is passed to the Doppler amount calculator 9. The other of the output signals in the intermediate frequency band is reproduced by the carrier regenerator 5 in a synchronous detection system using the carrier regenerator 5, the frequency is measured, and the received frequency value of the high frequency receiver is passed to the Doppler amount calculator 9. The Doppler amount is calculated using the reception frequency value and the demodulation information, and the position of the high-frequency receiver is calculated by the positioning operation unit 10.

Here, high frequency components are removed from the output signal of the loop filter 7 of the carrier regenerator 5 by the LPF 12. When the carrier regenerator 5 is normally locked, the output of the LPF 12 shows a constant DC voltage value, and when the carrier regenerator 5 is not locked, that is, when the
The output of F12 fluctuates randomly between 0V and 5V. Therefore, the output of the LPF 12 is divided into three regions, and if the region is the same at the previous time, it is determined that the output is normal. This operation is performed by the window comparator 13, the delay unit 14, and the decision unit 15.

FIG. 3 shows the waveform of each part at this time. When the RF input signal is deteriorated as shown in FIG.
The output of the PF is out of the loop of the PLL and fluctuates randomly between 0 V and 5 V as shown in FIG. 3B, and the output of the window comparator 13 is as shown in FIG. 3C. This is sampled and delayed using a clock faster than the symbol clock. The determination is made by the determiner 15 using the information of the signals before, two before and three before. FIG. 3D shows an output signal of the determiner 15. The output signal of the determiner 15 is used as alarm information in the positioning operation unit 10, the information from the Doppler amount operation unit 9 is normal when the alarm signal is active, and abnormal when the alarm signal is inactive.
Reflect on positioning calculation. This makes it possible to perform positioning even when the output of the carrier regenerator malfunctions due to some influence (for example, when the satellite is in the shadow of a building for a moment while moving or receives external disturbance noise for a moment). It can be performed normally and sufficient positioning accuracy can be obtained.

(Embodiment 2) FIG. 4 is a block diagram of a high-frequency receiver according to Embodiment 2 of the present invention. The output of the decision unit 15 in addition to FIG. 1 is connected to the AFC processing unit 11. The AFC processor 11 operates as if the output signal of the carrier regenerator 5 is gated with the signal from the determiner 15. Since the signal of the decision unit 15 is an alarm signal of the carrier regenerator, when this signal is inactive, it works to stop the operation of automatic satellite tracking which is automatic frequency control (AFC). Therefore, even if the satellite enters the shadow of the building for a moment and the C / N of the radio wave from the satellite deteriorates in a short time, the satellite is not lost because the AFC is not applied due to erroneous information, and the satellite is tracked. be able to. For this reason, positioning can be performed normally and sufficient positioning accuracy can be obtained.

(Embodiment 3) FIG. 5 is a block diagram of a high-frequency receiver according to Embodiment 3 of the present invention. In addition to FIG. 4, the output of the determiner 15 is connected to a visual display means 17 via a driver 16. The visual display means 17 is, for example, an LED, so that the user using the high frequency receiver can be notified of the alarm state. From this information, the user can improve the environment by cooperation such as changing the direction of the antenna for high frequency reception or the state of installation, so that positioning can be performed normally and sufficient positioning accuracy can be obtained. Can be.

[0020]

According to the first aspect of the present invention, a low-pass filter (LPF) is obtained from an output of a loop filter of a carrier regenerator.
And one of the outputs of the window comparator to the arithmetic unit via the delay unit,
The other is directly connected to the operation unit, and when the two are compared and matched, the signal is output to the positioning operation unit, and when the output of the carrier regenerator malfunctions, the output signal of the decision unit is used as alarm information to determine the position of the high-frequency receiver. Is calculated. Therefore, even when the C / N of the radio wave from the satellite is deteriorated, positioning can be performed normally and sufficient positioning accuracy can be obtained.

According to a second aspect of the present invention, the output of the decision unit is connected to an automatic frequency control (AFC) processing unit, and when the output of the carrier regenerator malfunctions, the output signal of the decision unit is used as alarm information for the high frequency receiver. AFC operation is being performed to track the satellite. Therefore, even when the C / N of the radio wave from the satellite deteriorates in a short time, the satellite can be tracked, the positioning can be performed normally, and sufficient positioning accuracy can be obtained.

According to the third aspect of the present invention, the output of the determiner is connected to a visual display means via a driver. Thereby, the user using the high frequency receiver can be notified of the alarm state. From this information, the user can improve the environment by cooperation such as changing the direction of the antenna for high frequency reception or the state of installation, so that positioning can be performed normally and sufficient positioning accuracy can be obtained. Can be.

As described above, when the high-frequency receiver of the present invention is used, sufficient accuracy is obtained in positioning calculation, more accurate positioning measurement can be realized, and the reliability of the positioning device is improved. Can be tracked sufficiently, line disconnection can be avoided, and line reliability can be improved, which is a great advantage in the field of electronic communication.

[Brief description of the drawings]

FIG. 1 is a block diagram of a high-frequency receiver according to Embodiment 1 of the present invention.

FIG. 2 is a configuration diagram of a window comparator, a delay unit, and a decision unit of the high-frequency receiver according to Embodiment 1 of the present invention.

FIG. 3 is a waveform diagram of the high-frequency receiver according to Embodiment 1 of the present invention.

FIG. 4 is a block diagram of a high-frequency receiver according to Embodiment 2 of the present invention.

FIG. 5 is a block diagram of a high-frequency receiver according to Embodiment 3 of the present invention.

FIG. 6 is a block diagram of a conventional high-frequency receiver.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Receiving antenna 2 Frequency converter 3 Local oscillator 4 Data demodulator 5 Carrier regenerator 6 Phase comparator (PD) 7 Loop filter 8 Voltage controlled oscillator (VCO) 9 Doppler amount operation unit 10 Positioning operation unit 11 AFC processing unit 12 Low pass Filter (LPF) 13 Window comparator 14 Delay unit 15 Judgment device 16 Driver 17 Visual display means

Claims (3)

[Claims] 1. A frequency converter for converting a radio wave from a satellite to an intermediate frequency band via a receiving antenna, a data demodulator for demodulating carrier frequency information at the time of transmitting a fixed pattern in the satellite, and reproducing a carrier wave. A phase comparator, a loop filter, a voltage-controlled oscillator, a carrier regenerator that randomly fluctuates the output of the no-signal loop filter around one voltage, and a Doppler amount calculator that calculates a Doppler shift amount. A high frequency receiver comprising: a positioning operation processing unit for calculating positioning; an automatic frequency control processing unit for tracking a satellite from an output of the carrier regenerator; and a local oscillator, wherein a loop filter of the carrier regenerator is provided. Is connected to a window comparator via a low-pass filter from one of the outputs, and one of the outputs of the window comparator is determined via a delay unit And the other is connected to the arithmetic unit as it is, and has a determiner for comparing the two and outputting a match / mismatch signal to the positioning arithmetic unit, and outputs an output signal of the determiner when the output of the carrier regenerator malfunctions. A high-frequency receiver characterized by calculating positioning of the receiver. 2. The automatic frequency control processing section according to claim 1, wherein an output of said determiner is connected to said automatic frequency control processing section, and an output signal of said determiner is used as alarm information in an automatic frequency control operation of a receiver when an output of said carrier regenerator malfunctions. The high-frequency receiver according to claim 1, wherein the high-frequency receiver tracks a satellite. 3. The apparatus according to claim 2, wherein an output signal of said judging device is connected to a visual display means via a driver, and alarm information is notified to a user using a high-frequency receiver. High frequency receiver.