JP2000031871A - Radio communication apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radio communication apparatus capable of excellently realizing diversity reception. SOLUTION: After selectively controlling a switch 22 from a state 22a to a state 22b, a control circuit 25 changeover-controls the switch 27 from an ON state to an OFF state before prescribed delay time in a reception circuit 24 elapses and changeover-controls the switch 28 from the OFF state to the ON state after the prescribed delay time elapses. Since RSSI(radio signal strength indicator) signals corresponding to radio waves received by an antenna 21 are appropriately supplied to the noninverted input terminal of a comparator 29 and RSSI signals corresponding to the radio waves received by an antenna 23 are appropriately supplied to the inverted input terminal of the comparator 29, in the control circuit 25, the selective control of the switch 22 is appropriately executed based on a compared result supplied from the comparator 29 and the diversity reception is excellently realized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radio communication device such as a portable telephone device provided with a plurality of receiving antennas capable of receiving radio waves.

[0002]

In recent years, with the advance of telecommunication technology, wireless communication devices such as portable telephone devices have become widespread. By the way, in general, these wireless communication devices receive radio waves transmitted from a radio base station and generate demodulated signals from the received radio waves with the aim of improving the quality of the demodulated signals. The configuration employs a known diversity reception method.
Hereinafter, a conventional wireless communication apparatus adopting the diversity receiving method will be described with reference to the configuration disclosed in Japanese Patent Application Laid-Open No. 9-186637.

FIG. 6 shows a main part of a configuration for realizing a diversity reception system disclosed in Japanese Patent Application Laid-Open No. 9-186637. In FIG. 6, antennas 1 and 2 are each configured to be able to receive a radio wave transmitted from a radio base station, and to output the received radio wave as a reception signal when the radio wave is received.
The switch 3 selects one of the antenna 1 and the antenna 2, and when in the first selection state (the state shown by the solid line in FIG. 6), the switch 3 transmits a reception signal corresponding to the radio wave received by the antenna 1. Output to the receiving circuit 4, while the second
(Indicated by a broken line in FIG. 6), a reception signal corresponding to the radio wave received by the antenna 2 is output to the reception circuit 4.

When receiving a signal from the switch 3, the receiving circuit 4 demodulates the received signal to generate a demodulated signal, outputs the demodulated signal, and receives a radio wave corresponding to the received signal. RSSI (Radio Si
gnal Strength Indicator) signal is output to the switch 5.

The switch 5 is in a first selected state (in FIG. 6,
(Indicated by a solid line), the RSSI signal supplied from the receiving circuit 4 is output to the non-inverting input terminal of the comparator 6. At this time, the voltage of the RSSI signal is applied to the capacitor 7. It is designed to be charged. The switch 5 is in the second selected state (FIG. 6).
(The state shown by the middle and broken lines), the RSSI signal is output to the inverting input terminal of the comparator 6, and at this time, the capacitor 8 is charged with the voltage of the RSSI signal. ing.

The comparator 6 compares the voltage of the RSSI signal supplied to its non-inverting input terminal with the voltage of the RSSI signal supplied to its inverting input terminal, and outputs the comparison result to the control circuit 9. Has become.

The control circuit 9 selectively controls the switch 10 by outputting a control signal to the switch 10. The switch 10 is in a first selected state (a state indicated by a solid line in FIG. 6). ), The clock signal supplied from the clock signal generator 11 is output to the switch 3 and the switch 5. On the other hand, when the clock signal is in the second selected state (the state shown by the broken line in FIG. 6), the control is performed. The receiving antenna selection signal provided from the circuit 9 is output to the switches 3 and 5.

According to such a configuration, the control circuit 9
First, by outputting a control signal to the switch 10, the switch 10 is selectively controlled to a first selection state (a state shown by a solid line in FIG. 6). At this time, the value of the clock signal output from the clock signal generator 11 is “0”.
, The switches 3 and 5 are each selectively controlled to the first selection state (the state shown by the solid line in FIG. 6), and accordingly, the radio wave received by the antenna 1 is received as a reception signal. An RSSI signal corresponding to the radio wave is applied to the non-inverting input terminal of the comparator 6, and the voltage is charged in the capacitor 7.

On the other hand, when the value of the clock signal output from clock signal generator 11 is "1", switches 3 and 5 are in the second selected state (the state shown by the broken line in FIG. 6). ), The radio wave received by the antenna 2 is supplied to the receiving circuit 4 as a reception signal, an RSSI signal corresponding to the radio wave is supplied to the inverting input terminal of the comparator 6, and Is charged in the capacitor 8. When the two RSSI signals are supplied to the non-inverting input terminal and the inverting input terminal of the comparator 6 as described above, the voltages of the two RSSI signals are compared, and the comparison result is output from the comparator 6 to the control circuit 9. You.

Next, the control circuit 9 outputs a control signal to the switch 10 to selectively control the switch 10 to a second selection state (a state shown by a broken line in FIG. 6).
By outputting a reception antenna selection signal based on the comparison result given from the comparator 6, the switch 3
And the switch 5 is selectively controlled to a selected state in which the voltage of the RSSI signal is larger, out of the first selected state and the second selected state, and the selected state is maintained.

In this manner, the antenna having the larger RSSI signal voltage indicating the reception intensity of the radio wave is selected from the antennas 1 and 2, and thereafter, the radio wave transmitted from the radio base station is selected. Therefore, when generating a demodulated signal from a radio wave, the quality of the demodulated signal can be improved.

However, the configuration disclosed in Japanese Patent Application Laid-Open No. Hei 9-186637 has the following problem. That is, the above-described receiving circuit 4 is generally configured such that, after receiving a received signal, an R corresponding to the given received signal is received due to a circuit configuration or a restriction of a wireless communication system.
It takes a certain time before the SSI signal is output,
As an example, a receiving circuit of a PHS (Personal Handyphone System) requires 5 to 10 microseconds.

Therefore, as in the configuration disclosed in Japanese Patent Application Laid-Open No. 9-186637, the switch 3 provided on the side of the receiving circuit 4 to which the received signal is input is connected to the switch 3.
In a configuration in which the switch 5 provided on the signal output side is simultaneously selected and controlled, for example, immediately after the switch 3 is switched from the first selected state to the second selected state, the antenna 2 is connected to the antenna 2. Although the received signal corresponding to the received radio wave is given to the receiving circuit 4, the receiving circuit 4 outputs an RSSI signal indicating the reception strength of the radio wave received by the antenna 1 earlier than that. As a result, the RSSI signal is supplied to the inverting input terminal of the comparator 6, and the voltage is charged to the capacitor 8.

Under such circumstances, there is a possibility that the comparison of the RSSI signal in the comparator 6 may not be performed well. If the comparison of the RSSI signal is not performed well, the diversity reception may be realized satisfactorily. There was a problem that you can not.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a diversity receiver that is provided with a plurality of receiving antennas capable of receiving radio waves. It is an object of the present invention to provide a wireless communication device capable of performing the above.

[0016]

According to the radio communication apparatus of the present invention, the control means selects one of the plurality of receiving antennas, that is, sets the selecting means to one selected state. Selection control is performed. At this time, when one receiving antenna receives a radio wave, the radio wave received by the one receiving antenna is output to the receiving circuit as a reception signal. Then, after a predetermined delay time has elapsed from the time when the received signal is given to the receiving circuit, one received signal indicating the received strength of the radio wave corresponding to the given received signal is output to the switching means. If the switching means is in an output-enabled state, the switching means outputs one reception intensity signal to the comparing means.

On the other hand, the control means selects another receiving antenna from among the plurality of receiving antennas, that is, selects and controls the selecting means in another selected state. At this time, the other receiving antenna receives radio waves. Then, a radio wave received by another reception antenna is output as a reception signal. Then, after a predetermined delay time elapses from the time when the received signal is given to the receiving circuit, another received strength signal indicating the received strength of the radio wave corresponding to the given received signal is output to the switching means. When the switching means is in a state capable of outputting, another reception intensity signal is output from the switching means to the comparing means.

Here, when the control means performs selection control from one selection state to another selection state, first, before the selection control, one switching strength signal is output from the switching means. The switching means is controlled so as to output one received signal to the comparing means.

Next, after the selection control, the control means controls the switching means to output one reception intensity signal before the predetermined delay time in the receiving circuit elapses from the time of the selection control. The switching means is controlled so that one reception intensity signal is not output to the comparing means.

Then, the control means switches the switching means so that another reception intensity signal is output from the switching means after a predetermined delay time in the receiving circuit has elapsed from the time when the selection control is performed. Is output to the comparing means. Then, the comparing means compares the one reception intensity signal provided from the switching means with the other reception intensity signal and outputs a comparison result, and the control means outputs the comparison result provided from the comparison means. On the basis of the,
The selection means is selected and controlled so that the reception intensity of the radio wave becomes maximum.

However, in this case, immediately after the selection means controls the selection, that is, when the radio wave received by one receiving antenna is given to the receiving circuit as a receiving signal, the signal is received by another receiving antenna. Immediately after shifting to give the received radio wave to the reception circuit as a reception signal, one reception intensity signal is output from the reception circuit and supplied to the comparison means, and a predetermined delay time in the reception circuit has elapsed. Later, another reception intensity signal is output from the reception circuit and supplied to the comparison means.

As described above, the selection control in the selection circuit provided on the side to which the reception signal is input in the reception circuit and the switching control in the switching circuit provided on the side to which the reception intensity signal is output are: Since the comparison is performed after the predetermined delay time in the receiving circuit is considered, the comparing means uses one reception intensity signal indicating the reception intensity of the radio wave received by one reception antenna, and the other reception antenna The comparison with the other received signal indicating the received signal strength of the received radio wave is favorably performed, and thereby the diversity reception can be satisfactorily realized.

According to the second aspect of the present invention, the comparing means includes a comparator to which the voltage of the reception intensity signal is applied, a capacitor capable of charging and discharging the voltage of the reception intensity signal, and discharging the voltage charged by the capacitor. Discharge switching means capable of switching the state of whether or not to perform,
The control means switches the discharge switching means so as to discharge the capacitor before performing the switching control so that the reception intensity signal is output from the switching means.

In this case, however, the comparison means can be easily configured by employing highly versatile electronic components such as a comparator and a capacitor. In addition, when the reception intensity signal is given to the comparison means, the voltage held in the capacitor before that is appropriately given to the comparison means, and when the next reception intensity signal is given to the comparison means. After the voltage held in the capacitor is once discharged, the voltage newly held in the capacitor is appropriately given to the comparing means, so that the comparing means uses one received signal and another received signal. The comparison with the signal is performed with high accuracy, and thereby, diversity reception can be better realized.

According to the wireless communication apparatus of the third aspect, the control means determines that the predetermined section consisting of the transient response ramp time, the start symbol and the preamble within one slot of the received signal is input to the receiving circuit within the predetermined period. The selection control of the selection means is executed.

In this case, in one section of a received signal, for example, in a section having high importance in communication of voice data, a calling identification code, a receiving identification code, and the like, selection control of a receiving antenna is executed. Since the voice data, the calling identification code and the destination identification code are not affected at all,
It is possible to satisfactorily demodulate voice data, a calling identification code, a receiving identification code, and the like from a received radio wave.

[0027]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) A first embodiment in which the present invention is applied to a portable telephone device will be described below with reference to FIGS. First, the antenna 21 (one of a plurality of receiving antennas according to the present invention) is a whip antenna provided to be able to be pulled out to a casing of a mobile phone device (not shown), for example, and the switch 22 (the present invention). (Selecting means referred to above) is connected to one fixed contact 22a. On the other hand, the antenna 23 (one of the plurality of receiving antennas according to the present invention) is a built-in antenna disposed inside the housing of the mobile phone, for example, and is connected to the other fixed contact 22b of the switch 22. Have been. The antenna 21 and the antenna 23 can receive a radio wave transmitted from a radio base station, and are configured to be able to output the received radio wave as a reception signal when the radio wave is received.

The movable contact 22c of the switch 22 is connected to the input terminal of the receiving circuit 24. An output terminal of the receiving circuit 24 is connected to a control circuit 25 (control means in the present invention).
output terminal is connected to a movable contact 2 of a switch 27 (switching means in the present invention) via a diode 26.
7a and the movable contact 28a of the switch 28 (switching means in the present invention).

When a reception signal is given in response to one of the antennas 21 and 23 receiving a radio wave, the reception circuit 24 demodulates the reception signal to generate a demodulation signal. A signal is output to the control circuit 25, and the signal R indicates the reception intensity of the radio wave corresponding to the reception signal.
The SSI signal is output to the switches 27 and 28. In this case, the receiving circuit 24
A predetermined delay time, specifically, about 7.8 microseconds, is required from when a received signal is given to when an RSSI signal corresponding to the given received signal is output.

The fixed contact 27b of the switch 27 is connected to the non-inverting input terminal of the comparator 29, one connection terminal of the capacitor 30, and the fixed contact 31a of the switch 31 (discharge switching means in the present invention).
0 other connection terminal and movable contact 31 of switch 31
b are each grounded.

The fixed contact 28b of the switch 28
The inverting input terminal of the comparator 29, one connection terminal of the capacitor 32 and the fixed contact 33a of the switch 33 (discharge switching means in the present invention) are connected to the other connection terminal of the capacitor 32 and the movable contact 33b of the switch 33. Are grounded respectively.

The output terminal of the comparator 29 is
It is connected to the control circuit 25. Incidentally, the comparison means in the present invention is composed of the comparator 29, the capacitor 30, the switch 31, the capacitor 32 and the switch 33.

The control circuit 25 is mainly composed of a logic circuit. As will be described later in detail, the control circuit 25 selectively controls the switch 22 and controls the switch 27,
The switch 28, the switch 31, and the switch 33 are configured to be switched.

Next, the operation of the above configuration will be described with reference to the time chart shown in FIG. 2 and FIG. still,
As radio waves received by the antenna 21 and the antenna 23, the portable telephone device is a simple portable telephone device (PHS: Pe:
rsonal Handyphone System), a broadcast channel (BCCH: Broadcast Control) is used as a control physical slot.
rol CHannel), channel for individual cell (SCCH: Sign)
aling Control CHannel) and paging channel (P
CH: Paging CHannel, etc., and an information channel (TCH: Traffic CHannel) as a physical slot for communication.
And high-speed associated control channel (FACCH: Fast Assoc)
In this case, as shown in FIG. 3, for example, an information channel (TCH) having a code length of 228 bits, a high-speed associated control channel (FA) as shown in FIG.
CCH). In FIG. 2, UW (synchronization word) to CRC in one slot shown in FIG.
The section of 212 bits of (error check bit) is referred to as “DAT
A ".

In FIG. 2, the control circuit 25 first outputs a first selection signal to the switch 22 as an initial state, thereby setting the fixed contact 22a and the movable contact 22c.
Is in the connected state, and the switch 22 is in the first selected state (FIG. 1).
Medium, a state shown by a solid line, one selected state in the present invention).

The control circuit 25 outputs an off signal to each of the switches 27 and 28, thereby turning the switches 27 and 28 off (the state shown by the solid line in FIG. 1). By outputting an ON signal to each of the switches 31 and 33, the switches 31 and 33 are turned on (the states indicated by broken lines in FIG. 1). At this time, the capacitors 30 and 32 are discharged by the switches 31 and 33 being on.

Here, when the radio wave transmitted from the radio base station is received by the antenna 21 and the antenna 23, the switch 22 is in the first selection state as described above. Radio wave is switch 2
2, the signal is supplied to the receiving circuit 24 as a received signal, and accordingly, the input level at the input terminal of the receiving circuit 24 rises from a weak level to a strong level over time (see t1 in FIG. 2). .

Next, the control circuit 25 outputs an off signal to each of the switches 31 and 33, thereby turning the switches 31 and 33 off (the state shown by the solid line in FIG. 1). 2, t2). At this time, the capacitors 30 and 32 are in a chargeable state because the switches 31 and 33 are off.

After a predetermined delay time, specifically, about 7.8 microseconds has elapsed after the reception signal was given to the reception circuit 24, when the RSSI signal was output from the reception circuit 24, the control circuit 25 outputs an ON signal to the switch 27 to turn the switch 27 on (shown by a broken line in FIG. 1) (see t3 in FIG. 2). At this time, the RSSI signal (one reception intensity signal in the present invention) output from the reception circuit 24 is supplied to the non-inverting input terminal of the comparator 29 via the diode 26 and the switch 27, and accordingly, the comparator 29 The input level at the non-inverting input terminal rises from a low level to a high level over time, and the capacitor 30 is charged with the maximum value C1 of the voltage of the RSSI signal. Further, the output level of the comparator 29 is kept at the high level.

Next, the control circuit 25 outputs the second selection signal to the switch 22 so that the fixed contact 22
b and the movable contact 22c are connected, and the switch 22
Is a second selected state (a state shown by a broken line in FIG. 1, another selected state in the present invention) (see t4 in FIG. 2). At this time, the radio wave received by the antenna 21 is transmitted to the receiving circuit 2
4 and is replaced by an antenna 23
Is supplied to the receiving circuit 24 via the switch 22 as a received signal.

Next, the control circuit 25 outputs an off signal to the switch 27, thereby turning the switch 27 off (shown by a solid line in FIG. 1) (see t5 in FIG. 2). At this time, the RSSI output from the receiving circuit 24
The signal is not supplied to the non-inverting input terminal of the comparator 29.

Next, the control circuit 25 outputs an ON signal to the switch 28 to turn on the switch 28 (shown by a broken line in FIG. 1) (see t6 in FIG. 2). At this time, the RSSI output from the receiving circuit 24
The signal (the other reception intensity signal referred to in the present invention) is applied to an inverting input terminal of a comparator 29 via a diode 26 and a switch 27.
The input level at the inverting input terminal 9 immediately rises from the low level to the middle level between the low level and the high level, and the capacitor 32 is charged with the maximum value C2 of the RSSI signal voltage. Further, as described above, the output level of the comparator 29 is held at the high level because the input level at the non-inverting input terminal of the comparator 29 is at the high level and the input level at the inverting input terminal is at the middle level. Become.

Next, the control circuit 25 controls the comparator 2
9 (comparison result in the present invention). At this time, since the output level of the comparator 29 is high, the maximum value C1 of the voltage charged in the capacitor 30 and the voltage of the capacitor 32 The maximum value of the applied voltage C
2, the maximum value C1 is larger, that is, the reception level of the radio wave received by the antenna 21 and the reception level of the radio wave received by the antenna 23 are the same as the reception level of the radio wave received by the antenna 21. Is determined to be larger, and a first selection signal is output to the switch 22, thereby connecting the fixed contact 22a and the movable contact 22c to the connected state, and setting the switch 22 to the first selected state (shown by a solid line in FIG. 1). State) (see t7 in FIG. 2).

Next, the control circuit 25 outputs an off signal to the switch 28 to turn the switch 28 off (shown by a solid line in FIG. 1) (see t8 in FIG. 2). At this time, the RSSI output from the receiving circuit 24
The signal is not supplied to the inverting input terminal of the comparator 29. Then, the control circuit 25 keeps this state while the reception signal is being input to the reception circuit 4 thereafter.

The control circuit 25 inputs a section (predetermined section in the present invention) consisting of a transient response ramp (4 bits), a start symbol (2 bits) and a preamble (6 bits) in the received signal to the receiving circuit 24. The selection control of the switch 22 as described above is executed during the specified period (predetermined period according to the present invention), that is, the data section (UW (synchronization word) to CRC (error check bit) The selection control of the switch 22 is not executed during the period in which the () section of (2)) is given to the receiving circuit 24.

In this case, as shown in FIG. 2, from the time when the switch 22 controls the selection from the first selection state to the second selection state, the second selection state changes to the first selection state. Until the selection control to the selection state, 15.6
It is 10.4 microseconds from the point in time at which the switch 27 is controlled to switch from the OFF state to the ON state in the switch 27 to the point in time when the control is switched from the ON state to the OFF state. It takes 7.8 microseconds from the time when the switching control is performed from the off state to the on state to the time when the switching control is performed from the on state to the off state.

When the received signal is no longer supplied to the receiving circuit 24 and the input level at the input terminal of the receiving circuit 24 falls from the high level to the low level (see t9 in FIG. 2), the control circuit 25 switches the switch. By outputting an ON signal to each of the switches 31 and 33, the switches 31 and 33 are turned on (FIG. 1).
The state is indicated by a middle and broken line) (see t10 in FIG. 2), and the state is returned to the above-described initial state. At this time, the capacitors 30 and 32 are connected to the switches 31 and 33, respectively.
Are turned on to discharge.

Thereafter, the control circuit 25 executes the same processing as the above-described series of processing (t11 in FIG. 2).
To t20). In this case, the output level of the comparator 29 is held at a low level because the input level at the non-inverting input terminal of the comparator 29 is at the middle level and the input level at the inverting input terminal is at the high level. The control circuit 25 determines the maximum value C1 of the voltage charged in the capacitor 30 and the
The maximum value C2 is larger than the maximum value C2 of the charged voltage, that is, the reception level of the radio wave received by the antenna 21 and the reception level of the radio wave received by the antenna 23 It is determined that the reception level of the received radio wave is higher, and the switch 22 is kept in the second selection state (the state shown by the broken line in FIG. 1) without outputting the first selection signal to the switch 22. (In FIG. 2, t
17).

The above is the description of the antenna 21 and the antenna 23
As shown in FIG. 3, the radio wave received at
The above description has been made on the assumption that the information channel (TCH) is a 28-bit information channel (FACCH). However, the present invention is not limited to this, and the code length is 240 bits as shown in FIG. Information channel (TC
H), a fast associated control channel (FACCH).

As shown in FIGS. 4B to 4D,
Individual cell channel (SCCH), broadcast channel (BC
CH) and paging channel (PCH), in which case the information channel (TC
H) Since the number of bits of the preamble is large compared to the high-speed associated control channel (FACCH) (62 bits), the control circuit 25 controls the selection of the switch 22 and the switches 27, 28, 31, and 33. The switching control may be performed over a relatively long period.

As described above, according to the first embodiment, after the switch 22 is selectively controlled from the first selection state to the second selection state, before the predetermined delay time in the reception circuit 24 elapses, The switch 27 is switched from the on state to the off state, and after a predetermined delay time has elapsed, the switch 2
8 is controlled to be switched from the off state to the on state, so that the R corresponding to the radio wave received by the antenna 21 is controlled.
The SSI signal is appropriately given to the non-inverting input terminal of the comparator 29, and the RSSI signal corresponding to the radio wave received by the antenna 23 is appropriately given to the inverting input terminal of the comparator 29. As a result, in the control circuit 25, the selection control of the switch 22 is appropriately executed based on the comparison result given from the comparator 29, and diversity reception can be favorably realized.

When comparing the RSSI signal corresponding to the radio wave received by the antenna 21 with the RSSI signal corresponding to the radio wave received by the antenna 23, the comparator 29, the capacitor 30, and the capacitor 32
Since a highly versatile electronic component is employed, the configuration can be simplified.

Since the switches 31 and 33 are controlled to be switched from the on state to the off state before the switches 27 and 28 are controlled to be switched from the off state to the on state, the capacitor 30 is switched.
After the capacitor 32 is discharged, the voltage of the RSSI signal is charged in the capacitor 30 and the capacitor 32. Thereby, in the control circuit 25, the selection control of the switch 22 is accurately executed based on the comparison result given from the comparator 29,
Diversity reception can be better realized.

Further, the selection control of the switch 22 is executed during a period in which a section consisting of a transient response ramp time, a start symbol and a preamble in one slot of the received signal is input to the receiving circuit 24. Therefore, in one section of the received signal, for example, in a section having high importance in communication of voice data, a calling identification code, a receiving identification code, and the like, the selection control of the switch 22 is not performed. Thus, the voice data, the calling identification code, the called identification code, and the like can be satisfactorily demodulated from the received radio wave without any influence on the calling identification code and the called identification code.

(Second Embodiment) Next, a second embodiment of the present invention will be described.
An embodiment will be described with reference to FIG. The same parts as those in the above-described first embodiment are denoted by the same reference numerals, and description thereof will be omitted. Hereinafter, different parts will be described. In the second embodiment, a switch 41 corresponding to the switch 27 and the switch 28 is provided instead of the switch 27 and the switch 28 in the above-described first embodiment. In this case, the RSSI output terminal of the receiving circuit 24 is connected to the movable contact 41a of the switch 41 via the diode 26. One fixed contact 41b of the switch 41 is connected to the non-inverting input terminal of the comparator 29, one connection terminal of the capacitor 30, and the switch 3
1 fixed contact 31a, the other fixed contact 41c is connected to the inverting input terminal of the comparator 29, one connection terminal of the capacitor 32, and the switch 33. Contact 41d
Is provided. In this case, the control circuit 25 controls the switching of the switch 41 by the switch 27 and the switch 28.
Is executed so as to correspond to the switching control.

As described above, according to the second embodiment, the same operation and effect as those of the first embodiment can be obtained. In particular, in the second embodiment, the two switches 27
And the switch 28 can be handled by one switch 41, and the number of parts can be reduced accordingly.

(Other Embodiments) The present invention is not limited to the above embodiment, but can be modified or expanded as follows. As a wireless communication device,
The invention is not limited to the mobile phone device, but may be another device such as a vehicle-mounted phone device. The number of antennas is not limited to two, and may be three or more. The comparing means is not limited to being constituted by a comparator or a capacitor, but may be constituted by other electronic components.

[Brief description of the drawings]

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

FIG. 2 is a time chart

FIG. 3 is a diagram showing a slot configuration of a communication physical slot.

4A is a diagram showing a slot configuration of a communication physical slot, and FIGS. 4B to 4D are diagrams showing a slot configuration of a control physical slot.

FIG. 5 is a view corresponding to FIG. 1 showing a second embodiment of the present invention.

FIG. 6 is a diagram corresponding to FIG. 1 showing a conventional example.

[Explanation of symbols]

In the drawing, 21 is an antenna (receiving antenna), 22 is a switch (selecting means), 23 is an antenna (receiving antenna),
24 is a receiving circuit, 25 is a control circuit (control means), 27 is a switch (switching means), 28 is a switch (switching means),
29 is a comparator (comparison means), 30 is a capacitor (comparison means), 31 is a switch (comparison means, discharge switching means), 32 is a capacitor (comparison means), 33 is a switch (comparison means, discharge switching means), 41 is This is a switch (switching means).

Claims (3)

[Claims] A plurality of receiving antennas capable of receiving a radio wave and outputting the received radio wave as a reception signal when the radio wave is received; and selecting one of the plurality of receiving antennas from the plurality of receiving antennas. Selecting means capable of outputting a received signal corresponding to the radio wave received by the selected receiving antenna; receiving the received signal from the selecting means, after a predetermined delay time has elapsed from that point, A reception circuit that outputs a reception intensity signal indicating the reception intensity of the radio wave corresponding to the signal, a switching unit that can switch a state of whether to output the reception intensity signal given from the reception circuit, and the selection unit. When at least two reception antennas are selected from the plurality of reception antennas, at least two reception intensity signals given from the switching unit are changed. Comparison means for comparing and outputting a comparison result; and control means capable of selectively controlling the selection means and switching control of the switching means, wherein the control means sets the selection means to one selected state. When performing the selection control from the other selection state, prior to performing the selection control, switching control of the switching means so that one reception intensity signal is output from the switching means, after the selection control, Before the predetermined delay time in the receiving circuit elapses from the time when the selection control is performed, switching control of the switching unit is performed such that one reception intensity signal is not output from the switching unit, and the switching in the receiving circuit is performed. After a predetermined delay time has elapsed, switching control of the switching means so that another reception intensity signal is output from the switching means,
The selection means is selectively controlled such that the reception strength of the radio wave is maximized based on the comparison result given by the comparison means in response to the output of the one reception strength signal and the other reception strength signal. A wireless communication device characterized by being configured as described above. 2. The comparator according to claim 1, wherein the comparator receives the voltage of the reception intensity signal, a capacitor capable of charging and discharging the voltage of the reception intensity signal, and determines whether the voltage charged by the capacitor is discharged. And control means for switching the state of the switching means so that a reception intensity signal is output from the switching means. 2. The wireless communication apparatus according to claim 1, wherein the discharge switching means is switch-controlled so that the capacitor discharges. 3. The reception signal includes at least a predetermined section including a transient response ramp time, a start symbol, and a preamble within one slot, and the control unit determines that the predetermined section in the reception signal is the reception circuit. 3. The wireless communication device according to claim 1, wherein the selection control of the selection unit is performed within a predetermined period input to the wireless communication device.