JP3058925B2 - Wireless communication device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radio communication apparatus such as an automobile telephone apparatus, a portable telephone apparatus, and a cordless telephone apparatus, and more particularly, to detecting a receiving carrier frequency of a radio channel and based on the detected receiving carrier frequency. And a wireless communication device having automatic frequency control means for controlling a transmission carrier frequency.

[0002]

2. Description of the Related Art In recent years, as one of wireless telephone systems,
A system employing a digital modulation / demodulation method has been proposed. This type of system digitizes and transmits not only control signals but also communication contents such as call voice between the base station and the mobile station.Securing confidentiality, improving data affinity, and improving radio frequency Can be used effectively.

[0003] By the way, in a radio communication device used for a mobile station of this type of system, an automatic frequency control system for controlling its own transmission carrier frequency in accordance with a reception carrier frequency transmitted from a base station is often employed. ing. In this method, for example, a reception intermediate frequency signal obtained by a reception circuit is input to a frequency counter, and the frequency of the reception intermediate frequency signal is counted by the frequency counter at every predetermined time (time base) set in advance. The count value is input to the control circuit. The control circuit generates a digital signal having a level corresponding to the count value, converts the digital signal into an analog DC voltage by a D / A converter, and supplies the analog DC voltage to a voltage controlled oscillator via a low-pass filter. The voltage controlled oscillator oscillates a frequency corresponding to the DC voltage value. Then, a local oscillation frequency corresponding to the oscillation frequency is generated by the reception PLL circuit and supplied to the reception circuit. The transmission PLL circuit generates a transmission carrier frequency corresponding to the oscillation output frequency of the voltage controlled oscillator, and supplies this frequency to the transmission circuit. Thus, the control of the transmission carrier frequency according to the reception frequency is performed.

[0004]

However, in order to implement such a method, there are the following problems to be improved. That is, in a mobile radio system, a mobile station often communicates while moving, so that a received carrier frequency may temporarily change under the influence of fading or the like. When the reception channel frequency changes in this way, this change is immediately reflected on the transmission channel frequency, and the transmission channel frequency greatly deviates from the prescribed frequency. Therefore, conventionally, for example, a method has been considered in which the time constant of the frequency control loop is set to be large, thereby reducing the influence of fading or the like. However, if the time constant is set to a large value in this manner, the transmission channel frequency gradually changes due to the time constant when setting the wireless channel, which causes another problem that the setting of the wireless channel cannot be performed quickly. I was

An object of the present invention is to provide a wireless communication apparatus which can quickly and accurately set a transmission frequency to a specified value at the time of setting a wireless channel, thereby providing excellent responsiveness.

Another object of the present invention is to make it possible to quickly and accurately set a transmission frequency to a specified value when setting a radio channel, and to temporarily reduce the reception frequency due to the effects of fading or the like in a steady state after setting the radio channel. An object of the present invention is to provide a wireless communication device having both responsiveness and stability of a transmission frequency so that the change is not immediately reflected in the transmission frequency even if the transmission frequency changes.

[0007]

In order to achieve the above object, the present invention provides an automatic frequency control means comprising: a receiving means for counting the radio frequency reception frequency or a frequency corresponding to this frequency in accordance with a plurality of time bases; Control means, when setting a radio line, firstly, at least one of the plurality of time bases is selected to perform coarse adjustment of the transmission frequency by selecting at least one of the short time bases. A fine adjustment of the transmission frequency is performed by selecting a time base longer than the time base selected in the adjustment.

According to another aspect of the present invention, there is provided an automatic frequency control means comprising: a receiving means for counting a radio frequency reception frequency or a frequency corresponding to the frequency according to a plurality of time bases; Control means. By this control means, at the time of setting a wireless channel, firstly, at least one of the plurality of time bases is selected to perform a coarse adjustment of the transmission frequency by selecting at least one of the short time bases. A time base longer than the base is selected to fine-tune the transmission frequency, and in a steady state after the wireless channel is set, the transmission time is controlled by selecting the longer time base among the plurality of time bases, and Detect the change of the receiving frequency from the counting result by the short time base,
According to this detection result, the count value based on the long time base is corrected.

[0009]

As a result, according to the present invention, when setting the radio channel, the transmission frequency is first roughly adjusted according to the count value of the reception frequency counted on a short time base, and after the transmission frequency falls within a certain range. Fine adjustment of the transmission frequency is performed according to the count value of the reception frequency counted on a long time base. Therefore, the transmission frequency is adjusted within a certain range in a short time, and is accurately converged to a specified value.

According to another aspect of the present invention, in a steady state after setting a radio channel, the transmission frequency is controlled in accordance with the count value of the reception frequency counted on a long time base. , The change is not immediately reflected in the change in the transmission frequency, and the transmission frequency is maintained relatively stably. Further, when the reception frequency temporarily changes, this change is detected from the short time base count value, and the long time base count value is corrected according to the detection result. For this reason, the count value based on the long time base is obtained by removing a temporary change in the reception frequency due to fading or the like, and therefore, the transmission frequency is extremely stably maintained without being affected by the fading or the like.

[0011]

FIG. 1 shows the configuration of a mobile station apparatus according to an embodiment of the present invention.

In FIG. 1, a radio communication signal transmitted from a base station (not shown) in a predetermined time slot of a radio channel being set includes an antenna 1 and a duplexer (DUP).
The signal is input to a receiving circuit (RX) 3 through a local oscillator 2 and is combined with a local oscillation signal output from a frequency synthesizer (SYN) 4 to be converted into an intermediate frequency signal. The received intermediate frequency signal is supplied to a digital code decoding circuit (MO
D) Digital demodulation is performed after frame synchronization and bit synchronization are established by 6. The synchronization signal obtained by the frame synchronization and the bit synchronization is transmitted to a control circuit (C
ONT) 20. The digital demodulated signal output from the digital code decoding circuit 6 includes a digital communication signal and a digital control signal. Of these, the digital control signal is supplied to the control circuit 20 and identified. On the other hand, the digital speech signal is supplied to an equalizer (EQL) 7 where the demodulated waveform is signal-equalized, and then error-correction decoded by an error-correction code decoding circuit (CH-COD) 8. Then, a speech codec (SP-C
OD) After being decoded at 9 and returned to an analog call signal, the signal is supplied to a receiver 11 via a voice switch 10 and is output from the receiver 11.

On the other hand, the transmission signal output from the transmitter 12 is input to the audio codec 9 via the audio switch 13 and is encoded there. The digital transmission signal obtained by this encoding is error-correction-coded by the error-correction code decoding circuit 8 together with the digital control signal output from the control circuit 20, and then input to the digital code decoding circuit 6. In the digital code decoding circuit 6, a modulation signal of an intermediate frequency corresponding to the digital transmission signal supplied from the error correction code decoding circuit 8 is generated and input to the transmission circuit (TX) 5. In the transmission circuit 5, the modulated signal is combined with a local oscillation signal output from the frequency synthesizer 4 and converted into a high-frequency signal. This high-frequency signal is amplified to a high frequency and then transmitted from the antenna 1 to the base station via the duplexer 2. Sent to.

The mobile station apparatus of this embodiment has a configuration applicable to a system in which a digital system and a current analog system coexist, that is, a dual-mode wireless telephone system. That is, when wireless communication is performed in an analog system instead of a digital system, the control circuit 20
Switches the audio switches 10 and 13 from the audio codec 9 to the analog audio processing circuit (A-AUD) 14. The demodulated signal output from the receiving circuit 3 is converted into an audio signal by the analog audio processing circuit 14, and then supplied to the receiver 11 via the audio switch 10,
Voice is output from the receiver 11. On the other hand, the transmission signal output from the transmitter 12 is input to the analog voice processing circuit 14 via the voice switch 13, where it is converted into an intermediate frequency signal and then converted to a high frequency signal by the transmission circuit 5. And transmitted from the antenna 1. Reference numeral 15 denotes an input display unit having switches such as a dial key and a transmission switch and a display, and 16 denotes a power supply circuit.

FIG. 2 shows a configuration of the receiving circuit 3, the frequency synthesizer 4, and the transmitting circuit 5 of the mobile station apparatus shown in FIG. In the figure, when a received high-frequency signal is input to a receiving circuit 3, it is first amplified by a high-frequency amplifier 31 and then converted into a first intermediate frequency signal by a first receiving mixer circuit 32. Circuit 33
Is converted into a second intermediate frequency signal. Then, the second intermediate frequency signal is amplified by the intermediate frequency amplifier 34 and then supplied to the digital codec 6 and also to the discriminator 18 in the analog audio processing circuit 14.

On the other hand, when the digital transmission signal output from the digital codec 6 is input to the transmission circuit 5, the first transmission mixer circuit 51 first outputs the transmission local oscillation signal output from the frequency synthesizer 4 to the transmission local oscillation signal. The signal is synthesized and converted into an intermediate frequency signal, and then converted into a transmission high frequency signal by a second transmission mixer circuit 53 via a buffer amplifier 52. The transmission high-frequency signal is amplified by a power amplifier (PA) 54 and then transmitted.

The frequency synthesizer 4 and the control circuit 20 have an automatic frequency control (AFC) function for controlling a transmission frequency according to a reception frequency from a base station. That is, the control circuit body 21 of the control circuit 20 outputs a control voltage (digital value) corresponding to a count value of a frequency counter described later, and the control voltage is D / A
After being converted into an analog value by the converter 41, the voltage-controlled crystal oscillation circuit (VCXO) is passed through the low-pass filter 42.
43. Then, a frequency corresponding to the analog value of the control voltage is oscillated and output from the VCXO 43, and this frequency is used as a reference frequency as the reception PLL circuit (R
XPL) 44. The reception PLL circuit 44
A first local oscillation frequency is generated based on the reference frequency, and the first local oscillation frequency is supplied to a first reception mixer circuit 32 via a buffer amplifier 45. Also,
The reference signal generated from the VCXO 43 is multiplied by a multiplication circuit (× N) 46 and then supplied to a second reception mixer circuit 33 via a buffer amplifier 47.

Further, the reference signal generated from the VCXO 43 is input to a transmission PLL circuit (TXPLL) 48. The transmission PLL circuit 48 generates a predetermined transmission local oscillation frequency based on the reference signal, and the transmission local oscillation frequency is supplied to a second transmission mixer circuit 53 via a buffer amplifier 49. The reference signal output from the VCXO 43 is a modulation PLL circuit (MODPLO).
L) 40. The modulation PLL circuit 40 generates a transmission intermediate frequency based on the reference signal, and the transmission intermediate frequency is supplied to a first transmission mixer circuit 51 via a buffer amplifier 50. Therefore,
The transmission circuit 5 generates a transmission frequency corresponding to the reception frequency in the reception circuit 3.

The control circuit 20 includes a first frequency counter 22 in addition to a control circuit body (CONT) 21.
a (COUNT1) and a second frequency counter (CO
UNT2) 22b and a first time generation circuit (TB1) 2
3a and a second time generation circuit (TB2) 23b. First and second time generating circuits 23a, 23
b is a time signal representing a first time base (for example, 10 msec) and a time representing a second time base (for example, 100 msec) longer than the first time base, based on the reference signal generated from the VCXO 43; These signals are supplied to a first frequency counter 22a and a second frequency counter 22b, respectively.

The first frequency counter 22a counts the frequency of the second intermediate frequency signal according to the first time base, and outputs the counted value to the control circuit body 21. That is, the frequency of the second intermediate frequency signal is detected every 10 msec.
On the other hand, the second frequency counter 22b counts the frequency of the second intermediate frequency signal according to the second time base,
The count value is output to the control circuit main body 21. That is, 10
The frequency of the second intermediate frequency signal is detected every 0 msec.

The control circuit main body 21 has, for example, a microcomputer as a main control section, and includes a transmission frequency control means 24 in addition to ordinary control means such as wireless channel connection control means. The transmission frequency control means 24 selectively selects the count values of the first and second frequency counters 22a and 22b in accordance with the operation state of the apparatus, that is, whether the radio line is set or in a steady state. It is used and performs a predetermined calculation, thereby controlling the transmission frequency.

Next, the operation of the apparatus configured as described above will be described according to the control procedure of the control circuit body 21. In the standby state, for example, in order for the user to make a call,
It is assumed that the transmission switch in the input display unit 15 is pressed. Then, as shown in FIG. 3, the control circuit body 21 first outputs a control voltage (digital value) corresponding to the frequency of the wireless line to be set in step 3a, as shown in FIG. Therefore, the VCXO 43 oscillates and outputs a frequency corresponding to the control voltage, and based on this frequency, the receiving PLL circuit 44 and the multiplying circuit 46 generate a first local oscillation frequency and a second local oscillation frequency, respectively. Therefore, the receiving circuit 3 starts receiving a wireless communication signal transmitted from a base station (not shown). Further, the modulation PLL circuit 4
0 and the transmission PLL circuit 48, the VCXO 43
The first intermediate frequency signal and the second intermediate frequency signal
An intermediate frequency signal is generated, and the transmission operation is started in the transmission circuit 5 by these signals.

On the other hand, the first time generation circuit 23a and the second time generation circuit 23b generate time signals corresponding to the first time base and the second time base, respectively, based on the oscillation frequency of the VCXO 43. , To the first and second frequency counters 22a and 22b.
Therefore, the frequency counters 22a and 22b start counting the reception intermediate frequency according to the first and second time bases, respectively.

When the circuit is started in this way, the control circuit main body 21 first starts controlling the frequency using the count value of the first frequency counter 22a using a short time base (10 msec). That is, in step 3b, VCX
After waiting for the time required for O43 to stabilize, a count value is taken from the first frequency counter 22a in step 3c. First, in step 3g, the direction of deviation of the reception intermediate frequency from the predetermined frequency, that is, whether the deviation is in the + direction or in the-direction, is determined from this count value. Next, in step 3e, the amount of frequency deviation is determined. Is the preset range Δ
It is determined whether or not the frequency is within f1 (for example, ± 200 Hz). If the result of this determination is that the deviation of the receiving frequency is greater than Δf1, the control voltage value is modified to reduce this deviation, and this modified control voltage is output in step 3f. Accordingly, the oscillation frequency of the VCXO 43 is modified according to the control voltage value, and accordingly, the local oscillation frequencies for reception and the local oscillation frequencies for transmission are also modified accordingly. Further, the time base signals generated from the first and second time generation circuits 23a and 23b are also corrected.

When the first correction of the oscillation frequency of the VCXO 43 is completed, the control circuit main unit 21 proceeds to step 3
g determines whether or not the next input timing from the first frequency counter 22a has been reached, that is, the first time base (10
msec) has elapsed, and if this 10 msec has elapsed, the flow returns to step 3c to return to the first frequency counter 22a.
The count value is taken from. Then, the direction of frequency shift and the amount of frequency shift are determined from the count value, and the frequency shift amount is Δ
If not, the control voltage is corrected and output in step 3f. Thereafter, similarly, the frequency shift amount becomes Δf
The control from step 3c to step 3g described above is repeated until the value falls within 1.

Now, it is assumed that the deviation of the reception frequency falls within Δf1 by the above control. Then, the control circuit main body 21 performs frequency control using the count value of the second frequency counter 22b using the next longer time base (100 msec). That is, as shown in FIG. 4, the control circuit main body 21 first corrects the control voltage in step 4a according to the determination results in steps 3d and 3e, and outputs the corrected control voltage. Then, in step 4b, it is determined whether or not the input timing from the second frequency counter 22b has come, that is, whether or not the second time base (100 msec) has elapsed.
The process proceeds to step c, where the count value is fetched from the second frequency counter 22b. Then, in steps 4d and 4e, the direction of frequency shift and the amount of frequency shift are determined from the count values. If the frequency shift does not fall within Δf2 (for example, ± 50 Hz), the process returns to step 4a and returns here. The control voltage is corrected and output according to the count value. Thereafter, similarly, the above-described control from step 4a to step 4e is repeated until the frequency deviation amount falls within Δf2.

FIG. 6 shows an example of a change in frequency at the time of setting the above-mentioned radio channel.
The change from P2 to P3 is performed by control using the count value of the first frequency counter 22a having a short time base.
The change from P3 to P4, P5 is the second with a long time base
The control is performed by using the count value of the frequency counter 22b.

By the control using the count value of the second frequency counter 22b, when the frequency shift amount falls within .DELTA.f2, the control circuit main body 21 shifts from step 4e to step 4f and receives first. It is determined whether or not synchronization has been established for the data, and when synchronization is established, a short burst is transmitted in step 4g. The short burst is used to measure the propagation delay between the base station and the short burst, and is composed of a combination of several types of frame patterns and "0" bit patterns. The base station measures the propagation delay time from the result of the short burst reception, inserts time alignment information into the response signal, and returns the response signal. Control circuit body 21 of mobile station apparatus
Detects in step 4h that the response signal has been returned from the base station, sets the transmission timing of the transmission time slot according to the time alignment information in step 4i. Then, in step 4j, speech data is transmitted using this transmission time slot, and thereafter, the communication control state (steady state) is established.

On the other hand, when a steady state is reached, the control circuit body 21
Performs steady-state control as follows, for example. That is, as shown in FIG.
At d, it is monitored whether or not the input timing of the count value from the second frequency counter 22b has come, that is, whether or not the second time base (100 msec) has elapsed. Then, every time 100 msec elapses, the process proceeds to step 5e,
The count value is taken in from the first frequency counter 22b. In addition, the control circuit main body 21 operates during the above monitoring periods (100 m
), the count values of the first frequency counter 22a are sequentially acquired at intervals of a first time base (10 msec) in steps 5a to 5c, and these count values are stored in the control circuit main unit 21.
In the RAM area. That is, the count value of the second frequency counter 22b is set to 1 in the control circuit main body 21.
Each time the count is taken, the count value of the first frequency counter 22a is taken ten times.

When the count value is fetched once from the first frequency counter 22b, the control circuit main body 21 first proceeds to step 5f to count each count value of the first frequency counter 22a held in the RAM area. It is determined whether or not any of them has changed by a predetermined amount or more. If there is any change, it is determined that the reception frequency has temporarily largely changed due to fading or the like during a period of 100 msec, and the process proceeds to step 5g. In this step 5g,
From the count value taken from the second frequency counter 22b,
The count value of the first frequency counter 22a in which a change equal to or more than the predetermined amount is detected is subtracted, and the count value of the first frequency counter 22a when there is no change is added. That is, the second including the frequency change due to the fading
For removing the change from the count value of the frequency counter 22b.

The second frequency counter 22b
Is completed, the control circuit main body 21 proceeds to step 5h. Then, in step 5h, it is determined whether or not the deviation of the reception frequency is within the allowable value Δf2 from the corrected count value of the second frequency counter 22b, and as a result of this determination, the deviation amount of the reception frequency is determined. Is Δf2
If not, the control voltage that has been output up to that point is output as it is in step 5i without correcting the control voltage. On the other hand, if a frequency deviation exceeding Δf2 occurs, the process proceeds to step 5j, where the control voltage value is corrected and output so that the frequency deviation falls within Δf2. On the other hand, if there is no change that is equal to or more than the predetermined amount in step 5f, it is determined that there is no temporary large change in the reception frequency due to fading or the like during the 100 msec period, and the process directly proceeds to step 5h. Transition.

Accordingly, for example, as shown in FIG. 7A, when the reception frequency temporarily changes largely due to fading or the like, this change is caused by the first time base having a short time base.
Is detected by the count value D of the frequency counter 22a.
Then, the value D 'corresponding to the count value D including this change is removed from the count value of the second frequency counter 22b,
Instead, the count value E for one time base is added. Therefore, the oscillation frequency of the VCXO 43, and consequently, the local oscillation frequency for reception and the local oscillation frequency for transmission,
It is stably maintained without being affected by the temporary change of the reception frequency due to the fading or the like. Note that FIG.
(A) shows the state of the count value of each of the first and second frequency counters 22a and 22b when a temporary large change in the reception frequency due to fading or the like does not occur, and the VCXO 43 at this time. Is controlled according to the count value of the second frequency counter 22b.

As described above, according to this embodiment, the first frequency counter 22a for counting the reception frequency on the short first time base (10 msec) and the reception frequency on the long second time base (100 msec) are used. And a second frequency counter 22b that counts the number of VCXs according to the count value of the first frequency counter 22a when setting the wireless line.
Since the oscillation frequency of O43 is controlled, and after the frequency falls within a predetermined range, the oscillation frequency of VCXO 43 is controlled according to the count value of second frequency counter 22b.
The setting of the wireless line can be set accurately in a short time.

In the presentation state after the setting of the radio line, the VC is controlled according to the count value of the second frequency counter 22b.
The oscillation frequency of the XO43 is controlled, and the first
A temporary change in the reception frequency due to fading or the like is detected from the count value of the frequency counter 22a, and a value corresponding to the change is removed from the count value of the second frequency counter 22b using the detection result. Therefore, the effect of a temporary change in the reception frequency due to fading or the like can be effectively removed, and an extremely stable frequency can be obtained.

The present invention is not limited to the above embodiment. For example, the correction of the count value of the second frequency counter 22b in the steady state may be performed without changing the length of the second time base. That is, as shown in FIG. 8, when a time-base count value obtained by the first frequency counter 22a that includes a large change due to fading or the like is detected, the count of the second frequency counter 22b is calculated. A portion of the numerical value corresponding to the time base including the above change may be replaced with a count value of another time base including no change among the time bases of the first frequency counter 22a. In this case, it is preferable to select a time base position to be replaced that is temporally separated from the time base position where the change in the count value is detected. Further, in the above example, the case where the frequency change due to fading or the like occurs in only one time base has been described as an example. However, when the frequency change spreads to a plurality of adjacent time bases, The count values in all time bases may be replaced with other time base count values in which the count values have not changed.

In the above-described embodiment, the first frequency counter 22a counts on the short first time base and the second frequency counter 22 counts on the long second time base.
b, but these frequency counters are 1
It can be shared by individuals. That is, the first frequency counter 22a and the second frequency counter 22b are used with a time lag during the wireless channel setting operation. Therefore, if the time base is externally switched, even one frequency counter can be used. It can be used without any trouble, and in a normal operation state, one frequency counter is operated on a short time base, and the count value of each time base obtained by this frequency counter is added by, for example, 10 time bases. In this case, a count value corresponding to a long time base may be obtained.

Further, the count value of the long time base obtained by the second frequency counter 22b may be fetched by the control circuit body 21 at short time base intervals as shown in FIG. By doing so, it is possible to control the frequency in a steady state quickly and in a short time while reducing the influence of temporary frequency fluctuation due to fading or the like.

In the above embodiment, the case where two types of time bases are used has been described. However, the control may be performed using three or more types of time bases. You may comprise so that it may change stepwise or continuously. In addition, the value of each time base, the means for creating the time base, and the like can be appropriately set or configured.

In addition, the configuration of the counting means for detecting the reception frequency, the circuit configuration of the automatic frequency control circuit, the control procedure and the control contents of the control circuit, etc. are variously modified without departing from the gist of the present invention. Can be implemented.

[0040]

As described above in detail, according to the present invention, the automatic frequency control means includes a counting means for counting a reception frequency of a radio line or a frequency corresponding to this frequency in accordance with a plurality of time bases, and a control means. By the control means, at the time of setting a wireless channel, first, at least one of the plurality of time bases is selected to perform coarse adjustment of the transmission frequency by selecting at least one of the short time bases. By selecting a time base longer than the selected time base and fine-tuning the transmission frequency, the transmission frequency can be set quickly and accurately to the specified value when setting up the radio line, thereby improving the responsiveness. An excellent wireless communication device can be provided.

According to another aspect of the present invention, the automatic frequency control means includes a counting means for counting a reception frequency of a radio line or a frequency corresponding to this frequency in accordance with a plurality of time bases, and a control means. By means, at the time of setting a wireless channel, first, at least one of the plurality of time bases is selected to perform a coarse adjustment of the transmission frequency by selecting at least one of the short time bases. A time base is selected to fine-tune the transmission frequency. In a steady state after setting the radio channel, the long time base is selected from the plurality of time bases to control the transmission frequency, and the short time base is set. The change of the receiving frequency is detected from the counting result by the above, and the counting value by the long time base is determined according to the detection result. By that is corrected,
The transmission frequency can be quickly and accurately set to the specified value when setting the radio line, and in the steady state after setting the radio line, even if the reception frequency temporarily changes due to the effects of fading etc., this change will not affect the transmission frequency. It can be prevented from being immediately reflected, and thereby a wireless communication device having both responsiveness and stability of the transmission frequency can be provided.

[Brief description of the drawings]

FIG. 1 is a circuit block diagram illustrating an overall configuration of a wireless communication device according to an embodiment of the present invention.

FIG. 2 is a circuit block diagram showing a main configuration of the device shown in FIG. 1;

FIG. 3 is a flowchart showing a control procedure and the first half of the control content when setting up a wireless channel of the apparatus shown in FIG. 2;

FIG. 4 is a flowchart showing a control procedure and a latter half of control contents when setting up a wireless channel of the apparatus shown in FIG. 2;

FIG. 5 is a flowchart showing a control procedure and control contents in a steady state of the apparatus shown in FIG. 2;

FIG. 6 is a diagram for explaining a frequency control operation of the device shown in FIG. 2 when setting a wireless channel.

FIG. 7 is a time chart for explaining a correction operation of a count value in a steady state of the apparatus shown in FIG. 2;

FIG. 8 is a time chart for explaining a correction operation of a count value in a steady state of the device according to another embodiment of the present invention.

FIG. 9 is a time chart for explaining an operation of taking in a count value in a steady state of the apparatus according to another embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Antenna, 2 ... Duplexer (DUP), 3 ... Receiving circuit (RX), 4 ... Frequency synthesizer (SYN), 5 ... Transmitting circuit (TX), 6 ... Digital code decoding circuit (MO
D), 7: Equalizer (EQL), 8: Error correction code decoding circuit (CH-COD), 9: Voice code decoding circuit (SP-C)
OD) 10, 13, voice switch, 11 receiver, 1
2: transmitter, 14: analog signal processing circuit (A-AU)
D), 15: input operation unit, 16: power supply circuit, 18: discriminator, 20: control circuit, 21: control circuit body, 22a: first frequency counter (COUNT1),
22b... Second frequency counter (COUNT2), 23
a: first time generating circuit (TB1), 23b: second time generating circuit (TB2), 31: high-frequency amplifier, 32, 5
DESCRIPTION OF SYMBOLS 1 ... 1st mixer circuit, 33, 53 ... 2nd mixer circuit, 3
4, 52 ... intermediate frequency amplifier, 40 ... modulation PLL circuit (M
ODPLL), 41 ... Digital / analog converter, 4
2: Low-pass filter (LPF), 43: voltage-controlled crystal oscillator (VCXO), 44: reception PLL circuit (RXPL)
L), 45, 47, 49, 50 ... buffer amplifier, 46
... multiplier circuit, 48 ... transmission PLL circuit (TXPLL),
54 Power amplifier (PA).

Claims (2)

(57) [Claims] 1. A wireless communication apparatus comprising an automatic frequency control means for detecting a reception frequency of a radio channel and controlling a transmission carrier frequency based on the detected reception carrier frequency, wherein the automatic frequency control means comprises: Counting means for counting the reception frequency of the radio line or the frequency corresponding to this frequency according to a plurality of time bases, and at the time of setting the radio line, first select at least one short time base from among the plurality of time bases, and A wireless communication apparatus comprising: a control unit for performing a coarse adjustment and performing a fine adjustment of a transmission frequency by selecting a time base longer than the time base selected in the coarse adjustment after the coarse adjustment is completed. 2. A wireless communication apparatus comprising an automatic frequency control means for detecting a reception frequency of a radio line and controlling a transmission frequency based on the detected reception frequency, wherein the automatic frequency control means comprises: Counting means for counting the receiving frequency or a frequency corresponding to this frequency in accordance with a plurality of time bases, and at the time of setting a radio channel, first at least one short time base among the plurality of time bases is selected to roughly adjust the transmission frequency. After completion of the coarse adjustment, a time base longer than the time base selected in the coarse adjustment is selected to finely adjust the transmission frequency. The transmission time is controlled by selecting the long time base, and the counting result by the short time base is selected. And control means for detecting a change in the reception frequency from the control signal and correcting the count value based on the long time base in accordance with the detection result.