JP2000357983A - Diversity controller for portable telephone and diversity control method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a reception characteristic stable, save power consumption and facilitate re-start of a channel. SOLUTION: A diversity deciding part 14 controls the change-over operation of an RF switch 3 and a logical switch 9, by comparing reception quality outputted from a demodulation logical circuit 10, a reception electric field strength outputted from a reception electric field detecting circuit 11, a phasing pitch outputted from a phasing pitch detecting circuit 12 and the threshold of a memory 13. In addition, a power source control part 15 turns on all circuits by supplying a power source in the case of a synthetic diversity and disconnects the power source to a radio part receiving circuit 5, a phase wave detector 7 and a synthesizing circuit 8 in the case of an antenna selection change-over diversity.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a diversity control device and a diversity control method for a mobile phone suitable for reception in a mobile communication system according to a radio wave environment.

[0002]

2. Description of the Related Art In a mobile telephone in a mobile communication system, when a radio wave environment such as a weak electric field or a fading environment is bad, reception characteristics are degraded and communication is hindered.

In order to solve such a problem, a diversity system has been proposed in which two antennas are prepared and a signal received by an antenna having the higher reception sensitivity among the two antenna outputs is demodulated.

[0004]

However, in the above-mentioned conventional diversity system, there is a problem that a combined diversity having an excellent diversity effect cannot be applied because the battery consumption becomes severe due to an increase in power consumption.

[0005] In addition, when shifting to a neighboring base station due to deterioration of the radio wave environment, the shifting process may fail because an appropriate neighboring base station cannot be found. In this case, it is necessary to continue communication on the original channel, but it may be difficult to restart the channel.

[0006] The present invention has been made in view of such a situation, and has a stable reception characteristic, reduced power consumption,
It is an object of the present invention to provide a diversity control device and a diversity control method for a mobile phone capable of facilitating channel restart.

[0007]

According to a first aspect of the present invention, there is provided a diversity control apparatus for a portable telephone, comprising: a plurality of antennas for receiving radio waves; an RF switch for switching antennas; and a plurality of radio units for performing radio communication. Circuit, a phase detector provided corresponding to these radio section receiving circuits, for detecting the instantaneous phase of the phase-modulated received wave from each radio section receiving circuit, and a phase detected by these phase detectors. A combining circuit for combining, a logic switch for switching between combining diversity and antenna selection switching diversity, a demodulating logic circuit for performing demodulation based on a detected phase value, and measuring an electric field strength of a received wave from a radio unit receiving circuit. A reception electric field detection circuit, a fading pitch detection circuit for detecting a fading state of a reception wave based on the measured electric field strength, and a combining diver. And a memory storing a threshold for determining any of the antenna selection switching diversity, and, based on the threshold, a diversity scheme determination unit that determines any of the combining diversity or the antenna selection switching diversity, A power supply control unit that performs on / off control of power supply to each unit. In addition, the threshold stored in the memory is determined to be the combination diversity by determining that the radio wave environment has deteriorated when any of the following factors occurs: the reception electric field is low, the fading is large, and the reception quality is poor. And a switch for switching back to antenna selection switching diversity when it is determined that the radio wave environment has become good quality when the factor disappears. The diversity determining unit compares the reception quality output by the demodulation logic circuit, the reception electric field strength output by the reception electric field detection circuit, the fading pitch output by the fading pitch detection circuit, and the threshold value of the memory. , A diversity identification signal for controlling the switching operation of the RF switch and the logical switch. Further, the logic switch can select which of the combined phase from the combining circuit and the non-combined phase of one of the phase detectors is demodulated based on the diversity system identification signal. Also, based on the diversity system identification signal, the power supply control unit supplies power to all the circuits in the case of the combining diversity and turns them on, and in the case of the antenna selection switching diversity, supplies the power to the radio unit receiving circuit, the phase detector and the combining circuit. The power can be turned off. Further, the RF switch can be incorporated in the radio unit receiving circuit. Further, the threshold value of the memory can be updated to a value suitable for the environment by estimating the transition of the radio wave environment based on the accumulation of the determination result by the diversity mode determination unit. The diversity control method for a mobile phone according to claim 8, wherein a first step of receiving radio waves by a plurality of antennas, a second step of switching the antennas by an RF switch, and wireless communication by a plurality of radio unit receiving circuits. A third step of detecting the instantaneous phase of the phase-modulated received wave from each of the radio unit receiving circuits by a phase detector, which corresponds to the radio unit receiving circuits; A fifth step of combining the phases detected by the combining circuit by a combining circuit, a sixth step of switching between combining diversity and antenna selection switching diversity by a logical switch, and demodulation by a demodulation logic circuit based on the detected phase values. A seventh step of performing, an eighth step of measuring the electric field intensity of the reception wave from the radio unit reception circuit by the reception electric field detection circuit, and measurement. A ninth step of detecting the fading state of the received wave by the fading pitch detection circuit based on the obtained electric field strength, and a tenth step of storing a threshold value for determining either the combining diversity or the antenna selection switching diversity. A step, an eleventh step of determining either the combining diversity or the antenna selection switching diversity based on the threshold value, and a twelfth step of performing on / off control of power supplied to each unit.
And a step of: Further, in the tenth step, when any of the following factors occurs: the reception electric field is low, the fading is large, or the reception quality is poor. A step of storing a threshold value, and a step of storing a threshold value for returning to antenna selection switching diversity by determining that the radio wave environment has been improved when the factor disappears. Can be. Further, in the eleventh step, the reception quality output by the demodulation logic circuit and
The received electric field intensity output by the received electric field detection circuit, and the fading pitch output by the fading pitch detection circuit,
The method may include a step of comparing the threshold value of the memory and a step of outputting a diversity identification signal for controlling the switching operation of the RF switch and the logical switch according to the comparison result. Further, the sixth step includes a step of selecting which of the combined phase from the combining circuit and the non-combined phase of one of the phase detectors is demodulated based on the diversity scheme identification signal. be able to. In the twelfth step, based on the diversity system identification signal, in the case of the combining diversity, power is supplied to all the circuits to turn them on, and in the case of the antenna selection switching diversity, the radio section receiving circuit, And a step of turning off the power to the synthesis circuit. Further, the tenth step includes a step of estimating a transition of the radio wave environment based on the accumulation of the determination results each time one of the combining diversity and the antenna selection switching diversity is determined. And updating the value to a value suitable for the environment. In the diversity control device and the diversity control method of the mobile phone according to the present invention, the diversity determination unit, the reception quality output by the demodulation logic circuit, the reception electric field intensity output by the reception electric field detection circuit,
The fading pitch output from the fading pitch detecting circuit is compared with the threshold value of the memory to control the switching operation of the RF switch and the logical switch, and the power supply control unit supplies power to all circuits in the case of the combined diversity. To turn on the power, and in the case of the antenna selection switching diversity, the power supply to the radio unit receiving circuit, the phase detector, and the combining circuit is cut off.

[0008]

Embodiments of the present invention will be described below.

FIG. 1 is a block diagram showing an embodiment of a diversity control apparatus for a portable telephone according to the present invention.

A diversity control device (hereinafter, simply referred to as a diversity control device) for a portable telephone shown in FIG. 1 includes antennas 1 and 2, an RF switch 3, a radio receiving circuit 4,
5, phase detectors 6, 7, synthesizing circuit 8, logical switch 9,
The circuit includes a demodulation logic circuit 10, a reception electric field detection circuit 11, a fading pitch detection circuit 12, a memory 13, a diversity determination unit 14, and a power supply control unit 15.

The antennas 1 and 2 receive radio waves. The RF switch 3 performs a switching operation according to each of the combining diversity and the antenna selection diversity. That is, in the case of the combined diversity, the radio waves arriving at the antennas 1 and 2 are input to the respective radio unit receiving circuits 4 and 5. In the case of the antenna selection diversity, one of the radio waves arriving at the antennas 1 and 2 is input to the radio unit receiving circuit 4 and is not input to the radio unit receiving circuit 5.

The radio section receiving circuits 4 and 5 include an RF switch 3
Captures radio waves passing through The phase detectors 6 and 7 detect the phases of the reception modulated waves received by the radio unit reception circuits 4 and 5, respectively. The combining circuit 8 combines the detected phase values.

The logic switch 9 selects which of the combined phase and the non-combined phase is to be demodulated. Here, the operation logic of the logic switch 9 is such that in the case of combining diversity, demodulation is performed using the phase value output from the combining circuit 8, and in the case of antenna selection diversity, demodulation is performed using the phase value output from the phase detector 6. Do.

The demodulation logic circuit 10 demodulates the phase value on the selected side. The reception electric field detection circuit 11 detects the reception electric field strength. The fading pitch detection circuit 12 detects a fading pitch.

The memory 13 stores a judgment threshold value. This determination threshold is used to determine that the radio wave environment has deteriorated when any of the following factors occurs: when the reception electric field is low, when the fading is large, or when the reception quality is poor, and switch to the combining diversity. And one for determining that the radio wave environment has become good when the factor disappears and switching back to antenna selection switching.

The diversity judging section 14 receives the reception quality output from the demodulation logic circuit 10, the reception electric field strength output from the reception electric field detection circuit 11, and the fading pitch detection circuit 1.
2 is compared with the judgment threshold value of the memory 13 to determine the diversity mode identification signal 16.
Is output. The RF switch 3 and the logic switch 9 are controlled by the diversity system identification signal 16.

In the case of combining diversity, the power supply control unit 15 supplies power to all circuits and turns them on, and in the case of antenna selection switching diversity, supplies power to the radio unit receiving circuit 5, the phase detector 7, and the combining circuit 8. It is turned off when it is turned off. Thereby, power consumption is reduced.

Next, the operation of the diversity control device having such a configuration will be described.

First, as the received electric field intensity detected by the received electric field detection circuit 11, the reception electric field level output from the radio section reception circuits 4 and 5 is used.

In this case, at the time of antenna selection switching diversity, the electric field strength corresponding to the selected antenna 1 or 2 is output. In the case of combining diversity, the maximum electric field strength in each receiving system or the average receiving electric field strength of each receiving system is output according to the standard of the combining circuit 8 to be used.

Next, the fading pitch detection circuit 12
Accordingly, the fading pitch is detected from the reception electric field level output from the reception electric field detection circuit 11. The fading pitch is a deviation of the reception electric field level output by the reception electric field detection circuit 11 within the own station slot.

The reception quality is determined by the demodulation logic circuit 10 based on the degree of difference between the input phase value and the ideal value.

The reception electric field level, the fading pitch and the reception quality thus obtained are input to the diversity judgment section 14. The determination by the diversity determining unit 14 is performed by software processing. As a result, a degree of freedom is provided for the determination in comparison with the threshold after the respective values of the time average, the number of times average, and the instantaneous value are obtained from the input detection elements.

Then, the diversity judging unit 14
It is determined whether the combining diversity or the antenna selection switching diversity is appropriate. The determination result is output to the RF switch 3, the logic switch 9, and the power control unit 15 as the diversity identification signal 16.

The RF switch 3 inputs radio waves arriving at the antennas 1 and 2 to the respective radio section receiving circuits 4 and 5 based on the diversity system identification signal 16 in the case of combined diversity. In the case of the antenna selection diversity, one of the radio waves arriving at the antennas 1 and 2 is transmitted to the radio receiving circuit 4.
And input to the radio receiver circuit 5 is not performed.

The logic switch 9 selects one of the combined phase of the combining circuit 8 and the non-combined phase of the phase detector 6 based on the diversity identification signal 16.

In addition, based on the diversity system identification signal 16, the power supply control unit 15 supplies power to all circuits and turns them on in the case of combined diversity. In addition, in the case of antenna selection switching diversity, the power supply control unit 15 turns off the power by turning off the power to the radio unit reception circuit 5, the phase detector 7, and the synthesis circuit 8. Thereby, power consumption is reduced.

As described above, in the present embodiment, the diversity judging section 14 controls the reception quality output from the demodulation logic circuit 10, the reception electric field intensity output from the reception electric field detection circuit 11, and the output from the fading pitch detection circuit 12. Since the switching operation of the RF switch 3 and the logical switch 9 is controlled by comparing the fading pitch to be performed with the threshold value of the memory 13, the reception characteristics are stabilized and the channel is easily restarted. be able to.

In the present embodiment, the power control unit 15
Thus, in the case of combining diversity, power is supplied to all circuits and turned on, and in the case of antenna selection switching diversity, the power supply to the radio receiver circuit 5, the phase detector 7, and the combining circuit 8 is cut off. Power consumption can be reduced.

Further, in the present embodiment, the reception electric field strength, the fading pitch, and the reception quality are used together as the criterion for switching the diversity system, so that the radio wave environment can be estimated from various points of view, and accurate. It is possible to make a determination.

Further, since the subsequent processing to the peripheral base station can be performed from an early stage, stable reception can be performed until the transition is completed. Therefore, when the transition to the peripheral base station fails, the original channel is changed. It is possible to prevent interruption of the call due to failure in restarting.

Although the present embodiment has been described in connection with the case where the number of receiving systems is two, the present invention is not limited to this example. For example, as shown in FIG. 2, an antenna 17, a radio unit receiving circuit 18, and a phase detector It is also possible to provide three systems in which 19 is added.

The present invention is not limited to this example, and the number of receiving systems may be four or more. Further, the reception system may be a single system. In this case, the same function as described above can be performed by using a plurality of antennas and performing analog synthesis immediately after input from each antenna.

Also, the case where the RF switch 3 is disposed in front of the radio receiving circuits 4 and 5 has been described. However, the present invention is not limited to this example.
It can be incorporated in.

That is, as shown in FIG. 3, BPF (Band Pass Filter) 4
a, 5a, RF (high frequency) amplifiers 4b, 5b, MIX
(Mixers) 4c and 5c and BPFs (bandpass filters) 4d and 5d are provided. Then, the RF switch 3 is arranged after the RF amplifiers 4b and 5b.

Further, as a method of diversity judgment, a method can be used in which the data is averaged by dividing it into sections in terms of time and frequency, and the arithmetic register is cleared each time the averaging for each section is completed. A method of clearing the operation register every time the determination changes can be used. It is also possible to use a method in which the CPU load is reduced by not performing the calculation normally, and the average calculation is performed after any of the judgment factors exceeds the threshold value. It is also possible to use a method of switching the diversity system immediately when any of the judgment factors exceeds the threshold value.

The threshold value of the memory 13 may be updated to a value suitable for the environment by estimating the transition of the radio wave environment based on the accumulation of the judgment result by the diversity system judging unit 14. it can. As a result, it becomes possible to stabilize the reception characteristics according to the change in the radio wave environment, reduce the power consumption, and facilitate the restart of the channel.

[0038]

As described above, according to the diversity control apparatus and the diversity control method for a portable telephone according to the present invention, the diversity judging section allows the reception quality output by the demodulation logic circuit and the reception quality output by the reception electric field detection circuit. By comparing the electric field strength, the fading pitch output by the fading pitch detection circuit, and the threshold value of the memory, RF
In addition to controlling the switching operation of the switches and the logical switches, the power supply control unit supplies power to all circuits in the case of combining diversity and turns them on, and in the case of antenna selection switching diversity, the radio receiving circuit, phase detector and combining Since the power supply to the circuit is cut off, it is possible to stabilize the reception characteristics, reduce the power consumption, and easily restart the channel.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating an embodiment of a diversity control device for a mobile phone according to the present invention.

FIG. 2 is a block diagram showing another embodiment in which the configuration of the diversity control device of the mobile phone shown in FIG. 1 is changed.

FIG. 3 is a block diagram showing still another embodiment in which the configuration of the diversity control device of the mobile phone shown in FIG. 1 is changed.

[Explanation of symbols]

 1, 2, 17 Antenna 3 RF switch 4, 5, 18 Radio section receiving circuit 4a, 5a, 4d, 5d BPF 4b, 5b RF amplifier 4c, 5c MIX 6, 7, 19 Phase detector 8 Combining circuit 9 Logical switch 10 Demodulation logic circuit 11 Received electric field detection circuit 12 Fading pitch detection circuit 13 Memory 14 Diversity judgment unit 15 Power supply control unit 16 Diversity system identification signal

Claims (13)

[Claims] 1. A plurality of antennas for receiving radio waves, an RF switch for switching the antennas, a plurality of radio unit receiving circuits for performing radio communication, and a plurality of radio unit receiving circuits provided corresponding to these radio unit receiving circuits. A phase detector for detecting the instantaneous phase of the phase-modulated received wave from the radio receiver circuit, a combining circuit for combining the phases detected by these phase detectors, and a logic for switching between combining diversity and antenna selection switching diversity A switch, a demodulation logic circuit that performs demodulation based on the detected phase value, a reception electric field detection circuit that measures an electric field intensity of a reception wave from the radio unit reception circuit, and, based on the measured electric field intensity, A fading pitch detection circuit for detecting a fading state of the received wave, and the combining diversity or the antenna selection switching diversity. A memory that stores a threshold value for determining any one of them; a diversity scheme determination unit that determines one of the combining diversity or antenna selection switching diversity based on the threshold value; and a supply to each of the units. A diversity control device for a mobile phone, comprising: a power control unit that controls power on / off. 2. The threshold value stored in the memory determines that the radio wave environment is degraded when any of the following factors occurs: a low reception electric field, a large fading, or a poor reception quality. And switching to the antenna selection switching diversity when the factor disappears and judging that the radio wave environment has become good quality and switching back to the antenna selection switching diversity. 2. The diversity control device for a mobile phone according to claim 1. 3. The diversity judging section includes: a reception quality output by the demodulation logic circuit; a reception electric field intensity output by the reception electric field detection circuit; a fading pitch output by the fading pitch detection circuit; The diversity control device for a mobile phone according to claim 1, wherein a diversity system identification signal for controlling a switching operation of the RF switch and the logic switch is output by comparing the threshold value with a threshold value. 4. The method according to claim 1, wherein the logic switch selects which of the combined phase from the combining circuit and the non-combined phase of one of the phase detectors is demodulated based on the diversity identification signal. The diversity control device for a mobile phone according to claim 1, wherein: 5. The power supply control section, based on the diversity scheme identification signal, supplies power to all circuits in the case of the combining diversity and turns on the circuit, and in the case of the antenna selection switching diversity, the radio section receiving circuit, 2. The diversity control device for a mobile phone according to claim 1, wherein power to the phase detector and the synthesis circuit is cut off. 6. The diversity control device for a mobile phone according to claim 1, wherein the RF switch is incorporated in the radio circuit receiving circuit. 7. The threshold value of the memory is updated to a value according to an environment by estimating a transition of a radio wave environment based on accumulation of determination results by the diversity mode determination unit. The diversity control device for a mobile phone according to claim 1. 8. A first step of receiving radio waves by a plurality of antennas, a second step of switching the antennas by an RF switch, and a third step of performing wireless communication by a plurality of radio unit receiving circuits. A fourth step of detecting, by a phase detector, the instantaneous phase of the phase-modulated received wave from each of the wireless section receiving circuits, corresponding to the wireless section receiving circuits; and a combining circuit for combining the phases detected by these phase detectors. A fifth step of switching between combining diversity and antenna selection switching diversity by a logical switch; a seventh step of performing demodulation by a demodulation logic circuit based on the detected phase value; An eighth step of measuring an electric field strength of a reception wave from the radio section reception circuit by a reception electric field detection circuit, and based on the measured electric field strength. Come, 10 for storing a threshold value for determining a ninth step of detecting the fading conditions of the received wave due to fading pitch detection circuit, one of the combining diversity or antenna selection switching diversity
A step of determining either of the combining diversity or the antenna selection switching diversity based on the threshold value, and a twelfth step of performing on / off control of a power supply supplied to each unit.
And a diversity control method for a mobile phone. 9. The tenth step includes determining that the radio wave environment has deteriorated when any of the following factors occurs: a case where the reception electric field is low, a case where the fading is large, and a case where the reception quality is poor. A step of storing a threshold value for switching to diversity, and a step of storing a threshold value for switching back to the antenna selection switching diversity by determining that the radio wave environment has become good when the factor disappears. The diversity control method for a mobile phone according to claim 8, wherein the method is included. 10. The eleventh step includes: receiving quality output by the demodulation logic circuit, received electric field intensity output by the received electric field detection circuit, fading pitch output by the fading pitch detection circuit, Comparing a threshold value of a memory with a threshold value of the memory, and outputting a diversity identification signal for controlling a switching operation of the RF switch and the logical switch according to the comparison result. Item 9. The diversity control method for a mobile phone according to Item 8. 11. The sixth step selects which of a combined phase from the combining circuit and a non-combined phase of one of the phase detectors is demodulated based on the diversity identification signal. 9. The diversity control method for a mobile phone according to claim 8, comprising a step. 12. In the twelfth step, based on the diversity system identification signal, a step of supplying power to all circuits in the case of the combining diversity and turning on the circuit, and a step of providing the antenna selection switching diversity 9. The diversity control method for a mobile phone according to claim 8, further comprising a step of turning off power to a radio unit receiving circuit, a phase detector, and a combining circuit. 13. The tenth step includes a step of estimating a transition of a radio wave environment based on accumulation of a determination result each time one of the combining diversity and the antenna selection switching diversity is determined. 9. The method according to claim 8, further comprising the step of updating the threshold value to a value corresponding to an environment in response to the request.