JP2002217764A - Radio equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide digital radio equipment adopting the SCPC(single channel per carrier) system of which the power consumption in a waiting state is reduced. SOLUTION: The circuits of the radio equipment are classified into a circuit that measures a reception electric field strength and the other circuits, power is supplied only to the circuit that measures a reception electric field strength in the waiting state, the circuit measures the reception electric field strength and when the reception electric field strength reaches a reference electric field strength or more, power is supplied to the other circuits so as to suppress the power consumption in the waiting state.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital radio of a press-talk system, and more particularly to a reduction in power consumption during standby.

[0002]

2. Description of the Related Art The prior art is based on FDMA (Frequency Divisi).
An on-multiple-access (wireless) system will be described.
FIG. 4 is a diagram illustrating a superframe structure used for the FDMA communication system and power on / off (ON / OFF) at the time of intermittent reception. In the FDMA communication system, there is a control channel (Carrier) for performing call connection and the like, and the mobile station normally receives this control channel and uses the BCCH.
(Broadcast Control Channel) broadcast information and regulation information, and the presence or absence of a call by PCH (Paging CHannel). This control channel has a superframe structure in which a functional channel is repeated in a plurality of frames as shown in FIG. That is, as shown in the upper part of FIG.
BCCH and PCH are intermittently received with 18 frames as one superframe. The lower part shows the on / off (ON / OFF) state of the radio wave at this time, and is in the off state except for the required reception slot.

[0003] This superframe structure is intended to assist intermittent reception of a mobile station. The mobile station receives a BCCH at the time of power-on, zone movement, etc., acquires broadcast information, regulation information, and the like, and then stands by. Enter the operation. During standby, it is sufficient to receive only the PCH allocated to the own station and confirm the communication request. For this reason, the mobile station suppresses power consumption by performing only the own station PCH of the reproduced superframe by the intermittent operation of the power supply of the receiving unit.

A conventional example of this standby operation will be described below with reference to FIG. FIG. 5 is a block diagram illustrating a configuration of a receiving unit of a conventional wireless device. 1 is an antenna, 1
4 is an antenna sharing unit, 3 is a high frequency processing unit, 4 is an intermediate frequency processing unit, 5 is a demodulation processing unit, 6 is a channel codec unit,
9 is a first local oscillator, 10 is a second local oscillator, 13
Is a power control unit. In FIG. 5, the power control unit 13
Performs on / off switching control of a given power supply, and in the on mode, the high frequency processing unit 3, the intermediate frequency processing unit 4, the demodulation processing unit 5, the channel codec unit 6, the first local oscillation The section 9 and the second local oscillation section 10 are supplied with power for operating them. The first local oscillator 9 supplies a first local oscillation signal to the high-frequency processing unit 3,
The second local oscillating unit 10 provides the intermediate frequency processing unit 4 with a second local oscillating signal.

[0005] The mobile station on the receiving side supplies a received signal received from the antenna 1 to the antenna sharing unit 14. The antenna sharing unit 14 separates only the signal in the reception band from the input signal and supplies the signal to the high frequency processing unit 3. The high-frequency processing unit 3 removes unnecessary frequency components from the input signal, amplifies the signal, and converts the signal into a first intermediate frequency by the first local oscillation signal input from the first local oscillation unit 9. This is given to the frequency processing unit 4. The intermediate frequency processing unit 4 removes an unnecessary component, amplifies the input signal converted into the first intermediate frequency, and performs a second local oscillation signal input from the second local oscillation unit 10. To a second intermediate frequency lower than the first intermediate frequency. In the intermediate frequency processing unit 4, the AGC (Auto Gain
Control) and received electric field strength information necessary for independent transmission output control to the demodulation processing unit 5.

[0006] The demodulation processing section 5 performs detection demodulation processing from the second intermediate frequency signal input from the intermediate frequency processing section 4 and the received electric field strength information, converts the signal into a baseband signal, and converts the converted baseband signal. A symbol synchronization process is performed using the band signal, and a data decoding process is performed. The decoded signal is provided to the channel codec unit 6. When synchronization with the partner station is not established, such as when the power is turned on or when the zone is moved, the channel codec unit 6 sets the synchronization word (S
W) and frame synchronization is established. Further, the superframe synchronization is established by detecting a superframe head synchronization word at the head of the superframe. That is, the channel codec unit 6 performs a series of processes such as descrambling, signal decomposition, and error correction, decodes the contents of the BCCH, determines the frame position of the own station PCH, and gives the PCH timing to the power control unit 13. . When the synchronization is established, the power supply control unit 13 supplies power only to the frame timing of the PCH of the own station based on the timing transmitted from the channel codec unit 6 and performs intermittent reception. At the time of transmission operation, a transmission signal from the transmission unit is provided to antenna sharing unit 14, and antenna sharing unit 14 transmits the input transmission signal via antenna 1.

FIG. 2 shows a conventional Single Channel (SCPC).
FIG. 4 is a diagram for explaining a connection sequence of direct communication between mobile stations in a Per Carrier) communication method. Also, FIG.
It is a figure which shows the connection sequence of the base station regular transmission output of PC system. In the SCPC communication method, since only voice communication of the press talk is performed, there is only a synchronization burst at the beginning of communication and a frame format for voice communication. For this reason, after the start of the communication, the voice communication is started continuously after transmitting the synchronous burst for the specified number of times. SCPC
The system is a digital version of PressTalk wireless system,
Unlike the case of the FDMA system, it has no control channel and has no superframe structure.

The SCPC communication system includes two systems: direct communication between mobile stations in which mobile stations directly communicate with each other, and continuous transmission base station communication via a base station that constantly transmits downlink signals. In both systems, transmission and reception operations are performed by press talk. That is, when the calling mobile station (the mobile station b in FIG. 2) presses on (ON), the mobile station transmits a frame called synchronization burst for pulling in synchronization a prescribed number of times, and then transmits an audio signal. When the communication is terminated by pressing off (OFF), the transmission is stopped after transmitting the empty line signal a specified number of times. In addition, the called mobile station (in FIG. 2, the mobile station
In a), the power is on and the device is always waiting. For example, when a sync burst is received,
Synchronization of the frame symbols and AGC control are performed to establish synchronization, and the communication channel is received. Further, upon receiving the empty line signal, the communication end operation is performed. Therefore, if no one is pressing on, no signal is sent.

Next, in the case of regular transmission base station communication, when communication is not being performed, an empty signal is transmitted from the base station, and when the mobile station and the base station command console are pressed on, a synchronization burst is defined. After transmitting the number of times, an audio signal is transmitted. Also, at the time of press-off, in the case of a mobile station call, transmission is stopped after transmitting a vacant line signal a specified number of times, and in the case of a base station command table call, the process proceeds to vacant line signal transmission. As described above, even in the case of the SCPC system regular transmission base station, an empty signal is always transmitted when there is no communication, and a synchronous burst is transmitted a specified number of times only when there is communication, and communication starts. Therefore, it is not known when communication starts. Therefore, if the call is not always received, the call may be cut off or the call may be missed. For this reason, intermittent reception cannot be performed and reception must always be performed, which consumes a large amount of power, and a portable wireless device or the like easily runs out of battery immediately.

[0010]

The above-mentioned prior art SC
In PC-based communication, it is not possible to know when the communication will start, so if it is not always received, the call may be interrupted or the call may be missed. And the power consumption is large, and the portable wireless device or the like immediately runs out of battery. An object of the present invention is to eliminate the above-mentioned disadvantages and to provide a wireless device with low power consumption.

[0011]

In order to achieve the above-mentioned object, a radio device according to the present invention comprises a means for comparing a received electric field strength with a specified electric field strength and a circuit required for measuring the received electric field strength. Means for turning on / off the power supply of the demodulation circuit is provided. The power supply is turned on when the received electric field strength exceeds the specified electric field strength, and the power supply is turned off otherwise. As a result, if the received electric field strength is equal to or less than the specified electric field strength, it is possible to operate some circuits intermittently by turning off the power of the demodulation circuits other than the circuit necessary for measuring the received electric field strength, The power consumption during standby can be reduced, and a wireless device with low power consumption is realized.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the SCPC communication system, since only voice communication of press talk is used, there are only a synchronization burst at the beginning of communication and a frame format for voice communication. For this reason, after the start of the communication, the voice communication is started continuously after transmitting the synchronous burst for the specified number of times. One embodiment of the present invention will be described with reference to FIG. FIG. 1 is a block diagram illustrating a configuration of a receiving unit of a wireless device according to an embodiment of the present invention. Components having the same reference numerals as those described in the related art have substantially the same functions and operations as those in the related art. In addition, 2 is an antenna switching unit, 11 is a reception electric field strength comparison unit, 12 is a power supply switching unit, 7 is an audio processing unit, and 8 is a speaker. Power is supplied to the first local oscillator 9, the second local oscillator 10, the high-frequency processing unit 3, the intermediate processing unit 4, and the reception electric field strength comparison unit 11. The antenna 1 is connected to the antenna switching unit 2 and the antenna switching unit 2
Is connected to the high frequency processing unit 3. High frequency processing unit 3
Is connected to the intermediate frequency processing section 4, and the output of the intermediate frequency processing section 4 is connected to the demodulation processing section 5 and the received electric field strength comparing section 11. The output of the demodulation processing unit 5 is connected to the channel codec unit 6, the output of the channel codec unit 6 is connected to the audio processing unit 7, and the output of the audio processing unit 7 is
Connect to The output of the first local oscillator 9 is connected to the high frequency processing unit 3, and the output of the second local oscillator 10 is connected to the intermediate frequency processing unit 4. The reference electric field intensity information is provided to the reception electric field intensity comparison unit 11, and the output of the reception electric field intensity comparison unit 11 is connected to the demodulation processing unit 5, the channel codec unit 6, and the audio processing unit 7. In the antenna switching unit,
A transmission signal is provided from the transmission unit.

In FIG. 1, a first local oscillation section 9 supplies a first local oscillation signal to a high frequency processing section 3, and a second local oscillation section 10 supplies a second local oscillation signal to an intermediate frequency processing section 4. give. The mobile station on the receiving side supplies the received signal received from the antenna 1 to the antenna switching unit 2. Antenna switching unit 2
Separates only the signal in the reception band from the input signal,
This is given to the high frequency processing unit 3. The high-frequency processing unit 3 removes unnecessary frequency components from the input signal, amplifies the signal, and converts the signal into a first intermediate frequency by the first local oscillation signal input from the first local oscillation unit 9. This is given to the frequency processing unit 4. The intermediate frequency processing unit 4 removes an unnecessary component, amplifies the input signal converted into the first intermediate frequency, and performs a second local oscillation signal input from the second local oscillation unit 10. To a second intermediate frequency lower than the first intermediate frequency. In the intermediate frequency processing unit 4, the AGC (Auto Gain Cont.
rol) and received electric field strength information necessary for independent transmission output control to the demodulation processing unit 5.

The intermediate frequency processing section 4 also provides the received electric field strength information to the received electric field strength comparing section 11. The reception electric field strength comparing unit 11 uses the received reception electric field strength information
A comparison is made as to whether or not the received electric field strength is equal to or greater than the reference electric field strength. If the received electric field strength is equal to or greater than the reference electric field strength, a power-on signal is sent to the power supply switching unit 12; The reference electric field strength is usually a fixed value, but can be changed according to the reception state. Upon receiving the power-on signal, the power supply switching unit 12 supplies power to the demodulation processing unit 5, the channel codec unit 6, and the audio processing unit 7, and the reception unit enters a demodulation operation.

That is, the demodulation processing unit 5 includes the intermediate frequency processing unit 4
From the second intermediate frequency signal and the received electric field intensity information, which are input from the first and second signals, are converted into baseband signals by performing detection and demodulation processing. With the first synchronization burst signal, high-speed symbol synchronization detection is performed based on the baseband signal, and data decoding processing is performed. The decoded signal is provided to the channel codec section 6, and the channel codec section 6
W) and frame synchronization is established. That is, the channel codec 6 performs a series of processes such as descrambling, signal decomposition, and error correction to separate the signal into signals for each functional channel.

When the channel codec unit 6 detects a synchronization word of a communication channel different from the synchronization word of the synchronization burst signal after the synchronization is established, the channel codec unit 6 sends the audio data of the TCH unit to the audio processing unit 7. The audio processing unit 7 converts the TCH data into an audio signal, amplifies the signal,
And output as sound. If the communication is terminated after transmitting the empty signal for the specified number of times, the received electric field intensity becomes lower than the reference electric field intensity.
Then, a power-off signal is output to the power switching unit 12. As a result, the power supply switching unit 12 stops supplying power to the demodulation processing unit 5, the channel codec unit 6, and the audio processing unit 7. Thereafter, the above operation is repeated when there is an input equal to or higher than the reference electric field intensity. At the time of transmission operation, a transmission signal from the transmission unit is provided to the antenna switching unit 2, and the antenna switching unit 2 transmits the input transmission signal via the antenna 1. Further, in the above embodiment, the reference electric field intensity is compared with the reception electric field intensity while continuously giving the reference electric field intensity to the reception electric field intensity comparison unit 11. However, the reference electric field intensity is stored in the reception electric field intensity comparison unit 11 in advance, and is stored. It may be compared with the reference electric field strength.

[0017]

According to the present invention, when the received electric field strength is lower than the specified value, it is possible to turn off the power supply other than the circuit for measuring the received electric field strength, and there is no communication to receive. In this case, power consumption can be suppressed, and power consumption can be reduced.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a receiving unit of one embodiment of a wireless device of the present invention.

FIG. 2 is a diagram for explaining a connection sequence of direct communication between mobile stations in a conventional SCPC communication method.

FIG. 3 is a diagram showing a connection sequence with a regular transmission base station of the SCPC communication method.

FIG. 4 is a diagram illustrating a superframe structure of the FDMA communication system and power on / off at the time of intermittent reception.

FIG. 5 is a block diagram showing a configuration of a receiving unit of a conventional wireless device.

[Explanation of symbols]

1: antenna, 2: antenna switching unit, 3: high frequency processing unit, 4: intermediate frequency processing unit, 5: demodulation processing unit,
6: channel codec section, 7: audio processing section, 8: speaker, 9: first local oscillation section, 10: second local oscillation section, 11: reception electric field strength comparison section, 12: power supply switching section, 13: Power control unit, 14: antenna common unit,

Claims (3)

[Claims] 1. A pre-talk system radio, comprising: a comparing unit that compares a received electric field strength with a predetermined value and outputs a control signal based on the comparison result; A switching unit for switching on / off of power supplied to a predetermined circuit, wherein when the received electric field intensity is less than the predetermined value, the switching unit turns off power supplied to the predetermined circuit. A wireless device characterized in that: 2. The wireless device according to claim 1, wherein a power supply to the predetermined circuit is in an off state.
When the reception electric field strength is larger than the predetermined value,
A wireless device for supplying power to the predetermined circuit. 3. The wireless device according to claim 1, wherein the predetermined circuit is a circuit other than a circuit that measures the reception electric field intensity of the wireless device. Radio to do.