JPH04275731A - Radio communication equipment - Google Patents

Abstract

PURPOSE:To supply a radio communication equipment in which expensive parts are not necessary to be used and which can easily and speedily adjust a frequency without opening an equipment. CONSTITUTION:A voltage controlled oscillator 12 is used as a reference oscillator. A key input part 15 for inputting correction information for correcting control voltage information corresponding to a reference frequency generated from the voltage controlled oscillator 12, a mode designation terminal 18 for setting a test mode for conducting a test on a local oscillation frequency and a correction control means 14a are provided. When correction information is inputted by the key input part 15 in a state where the test mode is set by the mode designation terminal 18, the correction control means 14a corrects control voltage information based on correction information.

Description

[Detailed description of the invention]

0001

[Industrial Field of Application] The present invention relates to wireless communication devices such as automobile telephones, mobile telephones, and cordless telephones, and in particular, uses a local oscillation frequency generated from a local oscillation circuit to generate received or transmitted signals. The present invention relates to a wireless communication device that performs frequency conversion.

0002

2. Description of the Related Art Generally, a radio telephone device generates a local oscillation frequency corresponding to a radio channel from a frequency synthesizer. Then, in the receiving circuit, this local oscillation frequency is mixed with the received high frequency signal to convert it into an intermediate frequency signal, and the received baseband signal is regenerated by further amplifying and detecting this intermediate frequency signal. In addition, the transmission circuit modulates the transmission carrier signal with the transmission baseband signal, mixes this modulated transmission carrier wave with the local oscillation frequency generated from the frequency synthesizer, converts it into a radio channel frequency, and transmits it from the antenna. It is configured as follows.

The deviation of the received local oscillator frequency and the deviation of the transmitted radio channel frequency in this type of device is determined by the frequency deviation of a reference oscillator provided for providing a reference signal to a frequency synthesizer. For this reason, a temperature compensated crystal oscillator (TCXO) is generally used as the reference oscillator. However, even if this TCXO is used, it is not possible to compensate for frequency shifts caused by changes in the crystal resonator over time. For this reason, after several years have passed, deterioration in reception sensitivity and deterioration in the sound quality of demodulated audio occur in mobile station equipment, and deterioration in reception performance in base stations due to shifts in transmission frequencies. Furthermore, if the amount of deviation in the oscillation frequency becomes large, not only will reception sensitivity and sound quality deteriorate, but control data will no longer be received accurately, making it impossible to control the connection with the base station, and causing interference with other adjacent wireless channels. This is extremely undesirable as it will cause interference to the This interference with other channels becomes a particularly serious problem in recent wireless telephone systems where channel separation is becoming narrower.

[0004] Conventionally, for example, after a few years have passed after a mobile station device has been used, the device is taken to a service station, and the device is disassembled at the service station to adjust the oscillation frequency of the reference oscillator. I was trying to adjust the capacitance of the trimmer capacitor.

[0005]

[Problem to be Solved by the Invention] However, as recent wireless telephone devices have become smaller, components have been mounted in a more dense and complex manner, so it is difficult to open the casing and adjust the internal components with high precision. It required skill and was extremely troublesome to operate.

[0006] Also, a digital TCX is used as a reference oscillator.
It has been considered to reduce the change in frequency deviation over time by using O, or to use a crystal resonator that has undergone sufficient aging to reduce the change over time in the crystal, but these methods would make the reference oscillator extremely expensive. There was a drawback.

[0007]The present invention has focused on the above-mentioned circumstances, and aims to provide a wireless communication device that does not require the use of expensive parts and can perform frequency adjustment easily and quickly without opening the device. do.

[0008]

[Means for Solving the Problems] In order to achieve the above object, the present invention uses a voltage controlled oscillator as a reference oscillator and stores control voltage information corresponding to the reference frequency generated from this voltage controlled oscillator. storage means for inputting correction information for correcting the control voltage information, mode setting means for setting a test mode for testing the local oscillation frequency, and correction control means. It is equipped with When correction information is input by the input means with the test mode set by the mode setting means, the control voltage information is stored in the storage means by the correction control means based on the correction information. This is to correct the .

[0009]

[Operation] As a result, according to the present invention, even if the oscillation frequency of the reference oscillator changes due to aging, the deviation in the transmission frequency can be detected using, for example, a tester while the device is set to the test mode by the mode setting means. By inputting correction information to bring this deviation closer to zero through an input means such as an existing dial keypad, the control voltage information in the storage means is rewritten to new control voltage information that takes into account the above secular change. It will be done. This eliminates the need for the adjuster to disassemble the device and replace parts, making it possible to adjust the frequency extremely easily and in a short time without requiring any skill. In addition, expensive digital T
Since there is no need to use a CXO or a crystal oscillator, the cost increase of the device can be kept to a minimum.

0010

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a circuit block diagram showing the configuration of a wireless communication device according to an embodiment of the present invention. This device is
It consists of a receiving circuit system, a transmitting circuit system, a control circuit system, and a power supply circuit system.

First, in the receiving circuit system, a radio signal transmitted from a base station (not shown) is received by an antenna 1 and then sent to a receiving circuit (R) via a duplexer (DUP) 2.
X) introduced in 3. This receiving circuit 3 first converts the received radio signal into a frequency synthesizer (SYN) which will be described later.
) 11 to convert it into a first intermediate frequency signal, and then the second intermediate frequency signal generated from a local oscillator provided in the receiving circuit 3.
The received local oscillation frequency is mixed and converted into a second intermediate frequency signal. Then, this second intermediate frequency signal is amplified and then detected to obtain a demodulated baseband signal. This demodulated baseband signal includes reception control data used for wireless channel connection control, etc., and a received audio signal. Of these, the reception control data is supplied to a control circuit 14, which will be described later, while the received audio signal is supplied to the received audio signal. Circuit (RX-AUD)
4. The receiving audio circuit 4 performs de-emphasis and expansion processing on the received audio signal, performs band-limited amplification, and then supplies the signal to the speaker 5 for amplification.

On the other hand, in the transmitting circuit system, the microphone 6
The transmitting audio signal of the speaker converted into an electrical signal is introduced into a transmitting audio circuit (TX-AUD) 7. The transmission audio circuit 7 performs pre-emphasis and compression processing on the transmission audio signal, performs band-limited amplification, and then supplies the signal to a transmission circuit (TX) 8 . The transmitting circuit 8 has a modulator, and the modulator modulates the high frequency using the transmitting signal outputted from the transmitting audio circuit 7 and the transmitting control data outputted from the control circuit 14. Then, this modulated high frequency is transmitted to a frequency synthesizer 11.
The transmission frequency signal is mixed with the transmission local oscillation frequency generated by the transmitter to convert it into a transmission frequency, and this transmission frequency signal is transmitted from the antenna 1 to the base station via the antenna duplexer 2.

By the way, the control circuit system includes a local oscillation circuit 10.
, a control circuit (CONT) 14, a key input section 15 including a dial key and a call switch, a display section 16 consisting of, for example, a liquid crystal display, and a memory circuit 17 consisting of, for example, an EEPROM. It is provided with a terminal 18 and a local oscillation output terminal 19 for outputting a transmission local oscillation signal to the outside of the device.

The local oscillator circuit 10 includes a frequency synthesizer 11, a reference oscillator 12 for providing a reference signal to the frequency synthesizer 11, and a digital-to-analog converter (D) for providing a control voltage to the reference oscillator 12. /A) consists of 13. Of these, the reference oscillator 12 is a temperature-compensated voltage-controlled crystal oscillator (V
CTCXO). The storage circuit 17 stores in advance the individual number code (ID code) of the device itself used when making a wireless connection with the base station, the telephone number for short-stay dialing, and control voltage data corresponding to the wireless channel. It is written.

The control circuit 14 is equipped with, for example, a microcomputer as a main control section, and has the following functions:
Normal processing such as processing of reception control data, generation of transmission control data, control of audio paths in the reception audio circuit 4 and transmission audio circuit 7, processing of inputting information from the key input section 15, and control of displaying information on the display section 16. In addition to the various functions described above, it is provided with local oscillation frequency correction control means 14a. The correction control means 14a enters a test mode when the test mode designating terminal 18 is grounded and a predetermined test command is inputted through the key input section 15, and in this state, the correction data inputted through the key input section 15 is set to the test mode. It performs control to rewrite the control voltage data stored in the storage circuit 17 in accordance with the above.

The power supply circuit system includes a rechargeable battery 21 made of, for example, a nickel-cadmium battery, and the output voltage Vcc of this battery 21 is supplied to each circuit system of the above-mentioned apparatus. In addition, 22 is a charging terminal, 2
3 is a backflow prevention diode, and 24 is a charging resistor.

Next, the operation of the apparatus configured as described above will be explained according to the control procedure of the control circuit 14. When the power switch (not shown) is turned on, the control circuit 14 is activated as shown in FIG.
As shown in FIG. 2, first, in step 2a, it initializes itself and performs predetermined initial settings for each circuit. For example, control voltage data is read from the storage circuit 17, and the oscillation frequency of the reference oscillator 12 is set according to this control voltage data. When the initial settings are completed, the control circuit 14 enters the standby state, and steps 2b, 2c, and 2d are performed at the call monitoring, incoming call monitoring, and test mode designation terminals 1 and 14, respectively.
Repeat the monitoring in step 8. If the originating switch is operated in this state, the control shifts to call origination control, and on the other hand, if control data into which incoming call information is inserted from the base station arrives, the control shifts to incoming call control.

Now, when adjusting the local oscillation frequency, the following procedure is used. That is, for example, a service station coordinator first connects the tester 30 used to measure the transmitting local oscillation frequency to the local oscillation output terminal 19.
Connect. Then, the test mode designation terminal 18 is connected to a ground terminal (not shown), and the key input section 15 is further used to input a recitation pattern using a predetermined input pattern.

Test mode designation terminal 1 in standby state
8 is grounded, the control circuit 14 detects this state in step 2d and starts test control. That is, Figure 3
As shown in FIG. 3, first, in step 3a, the input of the recitation pattern is monitored. In this state, when a recitation pattern is inputted by the key input unit 15, the control circuit 14 compares the input pattern of this recitation pattern with a predetermined pattern set in advance in step 3b, and if both patterns match, the recitation pattern is It determines that the input is correct and sets the test mode. On the other hand, if the recitation pattern is not input correctly, the device returns to the standby state. Here, as the recitation pattern, a complicated input pattern is used, such as pressing the keys "2", "5", "8", and "0" simultaneously for a certain period of time or more. Therefore, even if a person other than the adjuster accidentally or intentionally grounds the test mode designation terminal 18, there is almost no problem in which the test mode is actually set.

Now, when the test mode is set, the control circuit 14 monitors the input of test commands in step 3c. In this state, when the adjuster turns on the transmission switch as a test command, the control circuit 14 performs step 3d.
The local oscillation circuit 10 and the transmitting circuit 8 are set to the transmitting operation state. Then, the reference oscillator 12 outputs a reference oscillation frequency corresponding to the control voltage data currently stored in the storage circuit 17, and the frequency synthesizer 11 outputs the transmit local oscillation frequency generated based on the reference oscillation frequency. The frequency is output. Therefore, the adjuster uses the tester 30 to read the value of the above-mentioned transmitting local oscillation frequency, determines whether this frequency deviates from the specified transmitting local oscillating frequency, and, if it deviates, takes steps to reduce the amount of deviation to zero. The corrected data is input by operating the key input section 15. For example, the transmitting local oscillation frequency currently generated by the frequency synthesizer 11 is -5.0 ppm lower than the specified frequency.
If there is a deviation, press the star key * using the key input unit 15, and then input "5" and "0". Then, the control circuit 14 takes in the corrected data in step 3e, and calculates new control voltage data by performing calculations based on this corrected data in step 3f. Then, the control voltage data currently stored in the storage circuit 17 is rewritten with the calculated new control voltage data.

[0021] When the rewriting of the control voltage data is completed, the control circuit 14 performs steps 3g and 3h.
Then, monitoring to see whether the modified data has been re-inputted and monitoring to see if the test mode designation terminal 18 has become open is repeatedly performed. Then, the transmitting local oscillation frequency generated based on the new control voltage data still deviates from the specified frequency, and when the adjuster inputs correction data again to correct this deviation, the control circuit 14 performs step 3f. Return to and execute the process to rewrite the control voltage data again. Thereafter, the control circuit 14
The above control is repeatedly executed every time corrected data is input. On the other hand, when the transmitting local oscillation frequency is corrected to within a predetermined deviation from the specified frequency and the adjuster releases the grounding state of the test mode designation terminal 18, the control circuit 14 detects this in step 3h, and the transmitting circuit 8 to a non-operating state, and then returns to a standby state.

In this way, with this embodiment, even if the oscillation frequency of the reference oscillator 12 deviates from the specified value due to aging, as long as the tester 30 is available, there is no need to disassemble the device and replace circuit parts. The oscillation frequency of the reference oscillator 12 can be modified extremely easily and quickly without any additional work. Therefore, handling of the device can be made easier. Furthermore, there is no need to use a special vibrator whose temperature changes little over time, and inexpensive parts can be used, thereby preventing an increase in the cost of the device.

It should be noted that the present invention is not limited to the above embodiments. For example, in the embodiment described above, corrected data is input from the key input section 15, and the control circuit 14 calculates new control voltage data based on this corrected data. The value may be input as is from the key input section 15, and the control circuit 14 may calculate new control voltage data based on this frequency value. In this way, the adjuster can make adjustments without knowing the value of the specified frequency, and there is no fear that the adjuster will make a calculation error, making it easier and more accurate to make corrections. can.

Further, in the above embodiment, the adjuster inputs the correction data using the key input section 15, but a data input terminal for inputting the measurement data of the tester 30 is provided, and the control circuit is connected to the tester 30. The control voltage data may be modified based on the frequency measurement data taken in from the controller. In this way, the adjuster does not need to input any correction data, so the correction work can be further simplified.

Furthermore, in case the deviation of the transmitting local oscillation frequency from the specified frequency is large, a coarse adjustment step and a fine adjustment step are provided in the correction control procedure of the control circuit. You may also do this. In this way, even if the frequency deviation is large, accurate correction can be made in a short time.

Further, in the above embodiment, the transmit local oscillation frequency generated by the frequency synthesizer 11 is measured, but the oscillation frequency of the reference oscillator 12 may also be measured. Alternatively, the transmission frequency output from antenna 8 or antenna 1 may be measured.

Furthermore, in the above embodiment, the case where the device is brought to a service station with a tester and adjusted is explained as an example, but the adjustment can be made by exchanging data between the wireless telephone device and the base station. You may also do this. For example, a wireless line for communication is set up between the wireless telephone device to be adjusted and the base station, and in this state, the base station receives the transmission signal sent from the wireless telephone device and measures its frequency. do. Correction data representing this measured value or a deviation of this measured value from a specified value is transmitted from the base station to the radio telephone device as control data. The radio telephone device generates new control voltage data based on the corrected data sent from the base station and rewrites the data in the storage circuit. In this way, the owner of the wireless telephone device can easily perform the adjustment himself without requesting a service station. Incidentally, when performing the above adjustment, it is better to bring the wireless telephone device to a position sufficiently close to the base station in order to improve frequency measurement accuracy and perform highly accurate correction. In addition, the correction data sent from the base station is displayed on the display of the radio telephone device, and the owner inputs the displayed data from the key input section to correct the control voltage data of the memory circuit. It's okay. Furthermore, the modification performed using the base station as described above may be performed only at night when communication traffic is relatively low.

In addition, the control procedure and control contents of the modification control means, the configurations of the test mode setting means and modification information input means, etc. can be modified in various ways without departing from the gist of the present invention.

[0029]

As described in detail above, according to the present invention, a voltage controlled oscillator is used as a reference oscillator, and a memory for storing control voltage information corresponding to the reference frequency generated from this voltage controlled oscillator is provided. means, input means for inputting correction information for correcting the control voltage information, mode setting means for setting a test mode for testing the local oscillation frequency, and correction control means. , when correction information is input by the input means with the test mode set by the mode setting means, the correction control means reads the control voltage information stored in the storage means based on the correction information. By making this modification, it is possible to provide a wireless communication device that does not require the use of expensive parts and can perform frequency adjustment simply and quickly without opening the device.

[Brief explanation of the drawing]

FIG. 1 is a circuit block diagram showing the configuration of a wireless communication device in an embodiment of the present invention.

FIG. 2 is a flowchart showing a control procedure and control contents in a control circuit of the apparatus shown in FIG.

FIG. 3 is a flowchart showing control procedures and control contents in the control circuit of the device shown in FIG.

[Explanation of symbols]

1...Antenna, 2...Antenna duplexer (DUP), 3...Receiving circuit (RX), 4...Receiving audio circuit (RX-AU)
D), 5...Speaker, 6...Microphone, 7...Transmission audio circuit (TX-AUD), 8...Transmission circuit (TX),
10...Local oscillation circuit, 11...Frequency synthesizer (SY
N), 12... Reference oscillator (VCTCXO), 13... Digital-to-analog converter (D/A), 14... Control circuit (
CONT), 14a... Correction control means, 15... Key input unit, 16... Display (LCD), 17... Memory circuit (EEPR)
OM), 18... Test mode designation terminal, 19... Local oscillation output terminal, 20... Power supply circuit, 21... Battery, 22... Charging terminal, 23... Diode for backflow blocking, 24... Charging resistor, 30... Tester.

Claims (2)

[Claims] Claim 1. A wireless communication device that performs frequency conversion for transmitting or receiving communication signals using a local oscillation frequency generated from a local oscillation circuit, comprising a voltage controlled oscillator as a reference oscillator, the voltage controlled oscillator a local oscillation circuit for generating a local oscillation frequency corresponding to a wireless channel based on a reference frequency generated from the voltage controlled oscillator; and a storage means for storing control voltage information corresponding to the reference frequency generated from the voltage controlled oscillator. an input means for inputting modification information for modifying at least the control voltage information; a mode setting means for setting a test mode for testing the local oscillation frequency; and a mode setting means for setting a test mode for testing the local oscillation frequency; and correction control means for correcting the control voltage information stored in the storage means based on the correction information input by the input means in a state where the mode is set. . 2. The wireless communication device according to claim 1, wherein the local oscillation circuit includes a frequency output terminal for outputting a local oscillation frequency or a reference frequency generated by a voltage controlled oscillator to the outside of the device. Device.