JPH08125601A - Dual mode radio communication equipment - Google Patents

Abstract

PURPOSE: To improve the reliability in the acquisition of a control channel by avoiding a spurious radiation wave from being captured in mistake as a regular channel wave. CONSTITUTION: A D-channel of a 2nd control channel group is acquired, and whether or not PCI (Protocol Control Information) reached through the D- channel is set to '1' is discriminated in the step 2d, and in the case of the PCI set to '0', since it means that the PCI cannot be received through the D-channel of the 2nd control channel group, the information is regarded as a spurious radiation wave, and then the step 2g is proceeded. A paging channel whose reception electric field strength is a maximum is acquired from a 1st control channel group and the standby state is transited.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wireless communication device used as a mobile station in a mobile wireless communication system such as an automobile / mobile phone system or a cordless phone system, and particularly adopts a dual mode system as a wireless communication system. Wireless communication device.

[0002]

2. Description of the Related Art In recent years, a system adopting a dual mode system has been proposed as one of mobile radio communication systems. The dual mode is a system that uses both an analog mode and a digital mode.

In the analog mode, a communication device on the transmission side transmits a carrier wave by, for example, FM modulation with a voice signal and data, and a communication device on the reception side receives a modulated wave sent from the transmission side and performs FM demodulation. This is a method for reproducing voice and data. On the other hand, in the digital mode, a communication device on the transmission side encodes a voice signal and data, and a carrier wave is, for example, π / 4 shifted DQPSK (π / 4 Shifted, differentially encoded q) by the encoded signal.
uadrature phase shift keying) method, digitally modulates and transmits, and the receiving side communication device receives the modulated wave sent from the transmitting side and digitally demodulates it, and then decodes this demodulated signal This is a method of reproducing data. In the wireless communication in the digital mode, a method is used in which a plurality of time slots are time-division multiplexed and transmitted at one radio frequency.

By the way, in this type of system, there is a system in which a dual mode system is constructed by using a conventional base station dedicated to an analog mode as it is and adding a base station for dual mode thereto. . The control channels used in this type of system are newly added to a first control channel group (Primary Control Channel) that has been conventionally assigned to an analog mode base station and a frequency band different from the first control channel group. Second control channel group (Secondary Control Channel)
And a second control channel group is mainly allocated to the added dual mode base station. In addition,
If the first control channel group has a margin, this first control channel group may be assigned to the dual mode base station.

For example, in a dual mode cellular system in the United States, 313 ch to 354 ch are allocated as the first control channel group C1 as shown in FIG.
688 ch to 708 ch and 737 ch to 757 ch are allocated to the control channel group C2 of.

Further, since the analog mode base station and the dual mode base station have different capabilities, each base station is assigned to its own station in order to notify the mobile station of this difference in capabilities. Two control channel groups C1 and C2
Dedicated Control Channel (Dedicated Control Channel)
l; hereinafter referred to as D channel) is used to display protocol capability information (hereinafter referred to as PCI: Protocol Capability Indi
We call cator information). For example, an analog mode base station broadcasts PCI = 0, and a dual mode base station broadcasts PCI = 1.

The mobile station first captures the D channel C10 of the first control channel group C1 at the time of initialization after the power is turned on, and receives the PCI information broadcast from the base station by the first D channel C10. . And PCI = 0
If so, that is, if it is confirmed that the analog mode base station has been acquired, then acquisition of the D channel C20 of the second control channel group C2 is attempted. Then, when the D channel C20 of the second control channel group C2 is captured, it is determined that the dual-mode base station has been able to capture, and an arbitrary paging channel is captured from the second control channel group C2, Thereafter, the selected paging channel shifts to the standby state. The first control channel group C
PCI received by D channel C10 of 1 is PCI = 1
If so, it is determined that the dual mode base station to which the first control channel group C1 is allocated can be acquired,
A paging channel is arbitrarily acquired from the first control channel group C1 and thereafter the standby state is entered. Also,
When the D channel C20 of the second control channel group C2 cannot be captured, a paging channel is arbitrarily captured from the previously captured first control channel group C1.
After that, it shifts to the standby state.

That is, when acquiring the control channel, the mobile station preferentially selects a dual mode base station having a high function from the old analog mode base station and the newly established dual mode base station, and selects the control channel. When the control channel of the dual-mode base station is not captured, the control channel of the analog-mode base station is captured and the standby mode is entered.

[0009]

However, in the conventional system for preferentially capturing the control channel of the dual mode base station, the following problems may occur. That is, in the dual mode cellular system, for example, as shown in FIG. 4, the first control channel group C1
The communication channel group V is arranged in a lower frequency band than this, and spurious due to intermodulation between the first control channel group C1 and the communication channel group V depending on the arrangement of the frequencies of these channel groups C1 and V. Waves may occur in the frequency band of the second control channel group C2. For example, the D channel C10 (3 of the first control channel group C1
54ch) has a frequency of 880.62 MHz, and the channel V1 (993 ch) has a frequency of 869.1 MHz, then 880.62+ (880.62-869.1) = 89.
A spurious wave of 2.14 MHz appears at a position corresponding to 738ch in the frequency band of the second control channel group C2.

As described above, D of the first control channel group C1
When the spurious wave C10 'of the channel C10 appears in the frequency band of the second control channel group C2, the second control channel group C2 is used in the conventional control channel acquisition method described above.
When capturing the D channel C20 of the above, the spurious wave C10 'of the D channel C10 may be mistakenly captured, and further, the spurious wave C10' is captured as the paging channel to enter the standby state. There is. In this state, since the channel of the spurious wave C10 'does not actually exist in the second control channel group C2, even if the mobile station receives the incoming signal from the base station and transmits the response signal to it. , The response signal is not received by the base station. Further, even if the mobile station transmits an outgoing signal, the outgoing signal is not received by the base station as well. For this reason, the mobile station cannot perform any incoming / outgoing call operation.

The present invention has been made in view of such circumstances, and an object thereof is to prevent spurious waves from being mistakenly captured as a regular channel, thereby improving the reliability of control channel capturing operation. It is to provide a dual-mode wireless communication device capable of achieving the above.

[0012]

In order to achieve the above object, the present invention provides an analog mode base station which uses a first control channel group and a second mode which has a different frequency band from the first control channel group. Are used in a service area in which dual mode base stations that use the control channel group are mixedly installed, and either one of the first control channel group and the second control channel group is set at the time of initial setting. In the dual-mode wireless communication device that is selected and enters standby mode,
Capturing specific control channels for transmitting capability information in each of the first control channel group and the second control channel group, and representing the capability of the base station sent from the base station via these specific control channels. Receive each information,
It is determined whether it is appropriate that the received capability information has arrived via the control channel group acquired to receive the capability information. If it is determined to be valid, an arbitrary control channel is selected from the control channel group to shift to the standby state, and if it is determined to be invalid, the other control channel group is selected. In this case, an arbitrary control channel is selected from among the above to shift to the standby state.

[0013]

As a result, according to the present invention, for example, when the specific control channel of the second control channel group can be captured, the capability information received by this specific control channel is PCI =
1 or not, that is, the acquired channel is certainly the second
It is determined whether or not it belongs to the control channel group. Then, if PCI = 0, it is considered to be due to a spurious wave, the acquisition of the second control channel group is invalidated, the control channel of the first control channel group is acquired, and the standby state is entered. To do. Therefore, the spurious wave is not mistakenly captured as a regular control channel to shift to the standby state, and thus the normal control channel can always be captured. Therefore, it is possible to prevent the problem that the call cannot be made or received.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below by taking a dual mode cellular radio communication system as an example. FIG. 1 is a circuit block diagram showing a configuration of a dual-mode wireless communication device used as a mobile station in the system.

First, in the state where the digital mode is set, the switching circuits 10 and 17 follow the switching control signal SWC output from the control circuit 40, and the speech code decoding circuit 9 is provided.
It has been switched to the side.

In this state, a radio frequency signal transmitted from a base station (not shown) via a digital communication channel is received by an antenna 1 and then an antenna duplexer (DUP) 2
Is input to the receiving circuit (RX) 3 via. In the reception circuit 3, the reception radio frequency signal is mixed with the reception local oscillation signal output from the frequency synthesizer (SYN) 4 and frequency-converted into an intermediate frequency signal. The frequency of the received local oscillation signal generated from the frequency synthesizer 4 is the same as the control signal S output from the control circuit 40.
Instructed by YC. The received intermediate frequency signal is A
After being converted into a digital signal by the / D converter 6, it is input to the digital demodulation circuit (DEM) 7.

In the digital demodulation circuit 7, the received intermediate frequency signal is digitally demodulated and converted into a baseband coded digital received signal. The encoded digital received signal output from the digital demodulation circuit 7 includes
There are digital reception signals and digital control signals. The content of the digital control signal DCS is
It is captured by 0 and identified.

On the other hand, the digital received signal is input to the error correction code decoding circuit (CH-COD) 8. The error correction code decoding circuit 8 performs error correction decoding processing of the coded digital received signal supplied from the digital demodulation circuit 6. The error-correction-decoded coded digital reception signal is subsequently input to the voice code decoding circuit (SP-COD) 9. Speech code decoding circuit 9
Then, a voice decoding process of the encoded digital received signal is performed. The digital reception signal RS output from the voice code decoding circuit 9 passes through the switching circuit 10 and the echo canceller 30, and is converted into an analog reception signal by the D / A converter 11, and then the reception amplifier 12 is used.
Is amplified and output as loudspeaker from the speaker 13.

On the other hand, the speaker's transmission signal input to the microphone 14 is amplified by the transmission amplifier 15 and then A / D.
It is converted into a digital transmission signal by the converter 16 and then input to the echo canceller 30. The echo canceller 30 performs processing for canceling the acoustic echo included in the digital transmission signal. The digital transmission signal T output from the echo canceller 30
S is input to the voice code decoding circuit 9 via the switching circuit 17. The voice coding / decoding circuit 9 performs voice coding processing of the digital transmission signal.

The coded digital transmission signal output from the voice code decoding circuit 9 and the error correction code decoding circuit 8 together with the digital control signal output from the control circuit 40.
Is input to The error correction code decoding circuit 8 performs error correction coding processing on the coded digital transmission signal and the digital control signal. Then, the encoded digital transmission signal after the error correction encoding is input to the digital modulation circuit (MOD) 18. The digital modulation circuit 18 generates a modulation signal that is π / 4 shift DQPSK modulated according to the coded digital transmission signal, and this modulation signal is converted into an analog signal by the D / A converter 19 and then the transmission circuit ( TX) 5.

In the transmission circuit 5, the modulated signal is combined with the transmission local oscillation signal corresponding to the digital speech channel frequency, converted into a radio frequency signal, and further high frequency amplified. The transmission local oscillation signal is output from the frequency synthesizer 4 according to an instruction from the control circuit 40. The transmission radio frequency signal output from the transmission circuit 5 is supplied to the antenna 1 via the antenna duplexer 2 and transmitted from the antenna 1 to a base station (not shown).

Next, in the state where the analog mode is set, the switching circuits 10 and 17 output the switching control signal SWC from the control circuit 40, and the analog audio circuit 2 is operated.
It has switched to the 0 side.

In this state, a radio frequency signal sent from a base station (not shown) via an analog communication channel is received by the antenna 1 and then input to the receiving circuit 3 via the antenna duplexer 2, and this receiving circuit is received. At 3, the frequency is converted into an intermediate frequency signal. The reception intermediate frequency signal output from the reception circuit 3 is an analog audio circuit (ANALOG AU).
DIO) 20. This analog voice circuit 20
Then, the received intermediate frequency signal is FM-demodulated and then voice-amplified, and the demodulated baseband analog reception signal is once converted into a digital signal by the A / D converter 21, and then via the switching circuit 10. Echo canceller 30
Is input to The digital reception signal that has passed through the echo canceller 30 is returned to the analog reception signal by the D / A converter 11, amplified by the reception amplifier 12 and supplied to the speaker 13, and then output by the speaker 13. It

On the other hand, the speaker's transmission signal output from the microphone 14 is amplified by the transmission amplifier 15 and then converted into a digital transmission signal by the A / D converter 16, and then the echo canceller. It is input to 30. The echo canceller 30 performs processing for canceling the acoustic echo included in the digital transmission signal. In the analog mode, since the call quality is less deteriorated due to the acoustic echo, the echo canceller 30 may be set in the operation stop state. Echo canceller 30
The digital transmission signal TS output from the switching circuit 1
It is input to the D / A converter 22 via 7, converted into an analog signal here, and then input to the analog voice circuit 20.

The analog voice circuit 20 produces a modulated signal which is FM-modulated according to the transmission signal, and the modulated signal is inputted to the transmission circuit 5. In the transmission circuit 5, the modulated signal is mixed with the transmission local oscillation signal corresponding to the radio frequency of the analog speech channel generated from the frequency synthesizer 4, up-converted into a radio frequency signal, and further high frequency amplified to a predetermined output level. It Then, the radio frequency signal output from the transmission circuit 5 is supplied to the antenna 1 via the antenna duplexer 2 and transmitted from the antenna 1 to a base station (not shown).

By the way, the control circuit 40 has, for example, a microcomputer as a main control section, and has a PC in addition to usual control functions such as wireless connection control and call control.
I determination means 40a and control channel acquisition control means 40b
It has and.

The PCI judging means 40a receives P from the base station via the D channel C10 of the first control channel group C1 and the D channel C20 of the second control channel group C2.
It is determined whether the CI information is PCI = 1 or PCI = 0. Then, if the PCI arriving via the D channel C20 is PCI = 0, the D channel C20 is recognized as the spurious wave C10 'of the D channel C10.

The control channel acquisition control means 40b, at the time of initialization upon power-on, paging which should be waited from among the first and second control channel groups C1 and C2 based on the determination result of the PCI determination means 40a. Performs a series of controls to seize the channel.

Reference numeral 43 is a console unit (CU)
The console unit 43 has a key group such as dial keys, call key, end key, volume control key, and mode designation key, and an LCD display for displaying the telephone number of the call partner terminal and the operating state of the device. A vessel is provided. 42 is a power supply circuit, and this power supply circuit 4
2, the predetermined operating power supply voltage V based on the output of the battery 41
cc is generated and supplied to each circuit.

Next, the operation of the mobile station apparatus configured as described above will be described according to the control procedure of the control circuit 40. FIG. 2 is a flowchart showing the control procedure and control contents.

When the power is turned on, the control circuit 40 initializes the operating state of each part of the apparatus and then executes control channel acquisition control for shifting to the standby state. That is, first, in step 2a, D of the first control channel group C1
An attempt is made to capture the channel C10, and the D channel C10 is used to receive and detect the PCI information transmitted by the base station. Then, in step 2b, it is determined whether or not PCI = 0. Then, if PCI = 0, it is recognized that the transmission source of the D channel C10 currently being acquired is the analog mode base station.

When this determination is completed, the control circuit 40 then proceeds to step 2c and attempts to capture the D channel C20 of the second control channel group C2, and if captured, uses this D channel C20. The PCI information transmitted by the base station is received and detected. Then, in step 2d, PCI = 1
If PCI = 1, it is recognized that the transmission source of the D channel C20 currently being acquired is the dual mode base station. Then, the process proceeds to step 2e, where a paging channel reception search of the second control channel group C2 is performed. When the paging channel with the highest received electric field strength is detected by this search, this paging channel is set thereafter. And shift to the standby state.

On the other hand, suppose now that the first control channel group C1
By the intermodulation of the D channel C10 and the speech channel V, a spurious wave C10 'of the D channel C10 is generated, and this spurious wave C10' is in the frequency band of the second control channel group C2 as shown in FIG. Suppose that it appeared in. Then, it is assumed that the mobile station captures this spurious wave C10 'as the D channel of the second control channel group C2 in step 2c.

Then, according to the conventional method, this spurious wave C10 'is unconditionally applied to the second control channel group C2.
It is recognized as the D channel C20. Then, the paging channel is searched from the second control channel group C2, and the received wave having the highest received electric field strength is captured as the paging channel. However, if the mobile station cannot receive the paging channel of the second control channel group at this time because there is no dual-mode base station in the periphery of the mobile station, the mobile station receives the spurious wave C10 '. It will be captured as a paging channel and will shift to a standby state.

On the other hand, in the control channel acquisition system of the present embodiment, when the D channel of the second control channel group C2 is acquired, the PCI arriving via this D channel in step 2d as described above. It is determined whether the information is PCI = 1. That is, it is determined whether the source of this PCI information is indeed a dual mode base station. When PCI = 1, the operation for searching the paging channel from the second control channel group C2 is performed, and if the paging channel is found, the standby state is entered. On the other hand, if PCI = 0, this information cannot be received by the D channel C20 of the second control channel group C2.
This is regarded as a spurious wave, and the process proceeds to step 2g. In step 2g, the control circuit 40 searches for a paging channel in the first control channel group C1 and captures the received wave with the highest received electric field strength as the paging channel among the received waves received by this search. .

Therefore, there is no fear of erroneously capturing the spurious wave C10 'as the D channel and paging channel of the dual mode base station. In step 2b, the D channel C of the first control channel group C1
When the PCI information received by 10 is PCI = 1, the control circuit 40 recognizes that the transmission source of this PCI information is the dual mode base station to which the first control channel group C1 is allocated, and Move to 2f. Then, in this step 2f, the console unit 4
It is determined whether or not the analog mode is designated by the mode designation key of No. 3, and if the analog mode is not designated, the process proceeds to step 2g, where the received electric field strength is selected from the first control channel group C1. Captures the largest paging channel and shifts to the standby state.

On the other hand, when the analog mode is designated by the mode designation key, the process returns to step 2a to receive the D channel of the analog mode base station, and the D channel of the first control channel group C1 is again received. Try to capture.

As described above, in this embodiment, when the D channel of the second control channel group C2 is captured, it is determined in step 2d whether or not the PCI information arriving via this D channel is PCI = 1. However, if PCI = 0, this PCI information cannot be received by the D channel C20 of the second control channel group C2.
Considered to be a spurious wave, and moved to step 2g,
Here, the paging channel having the highest received electric field strength is captured from the first control channel group C1 and the standby state is entered.

Therefore, in this embodiment, the spurious wave C1 of the D channel C10 is produced by the intermodulation of the D channel C10 of the first control channel group C1 and the communication channel V.
Even if 0'is generated and this spurious wave C10 'appears in the frequency band of the second control channel group C2, this spurious wave C10' is mistakenly captured as the D channel and paging channel of the dual mode base station. This makes it possible to reliably make and receive calls.

The present invention is not limited to the above embodiment. For example, in the above embodiment, in the system in which the analog mode base station is not assigned the second control channel group C2, the second control channel group C2
When PCI = 0 is received on the D channel of the above, this is recognized as a spurious wave, but in the system in which the first control channel group C1 is not assigned to the dual mode base station, Control channel group C1 D
When PCI = 1 is received on the channel, it may be recognized as a spurious wave.

In the system in which only the first control channel group C1 is assigned to the analog mode base station and only the second control channel group C2 is assigned to the dual mode base station, the second control channel is used. Group C
If PCI = 0 is received on the second D channel, this is recognized as a spurious wave, and the first control channel group C1
When PCI = 1 is received on the D channel of, this may be recognized as a spurious wave.

Furthermore, after shifting to the standby state, the communicable mode may be displayed on the display device according to the type of the captured base station. In this way, the user can clearly know whether the communication is possible only in the analog mode or both the digital mode and the analog mode.

In addition, the control procedure and the control content of the control channel acquisition control, the type of the wireless communication device, the configuration thereof, and the like can be variously modified and implemented without departing from the scope of the present invention.

[0044]

As described above in detail, in the dual mode wireless communication device of the present invention, a specific control channel for transmitting capability information is captured in each of the first control channel group and the second control channel group. , Each of which receives information indicating the capability of the base station sent from the base station via these specific control channels, and the received capability information is
It is determined whether it is appropriate to arrive via the control channel group acquired to receive this capability information.
If it is determined to be valid, an arbitrary control channel is selected from the control channel group to shift to the standby state, and if it is determined to be invalid, the other control channel group is selected. An arbitrary control channel is selected from the above to shift to the standby state.

Therefore, according to the present invention, it is possible to prevent a spurious wave from being mistakenly captured as a regular channel, thereby providing a dual mode wireless communication device capable of improving the reliability of the control channel capturing operation. can do.

[Brief description of drawings]

FIG. 1 is a circuit block diagram showing a configuration of a dual-mode wireless communication device according to an embodiment of the present invention.

2 is a flowchart showing a control procedure and control contents of control channel acquisition control by a control circuit of the device shown in FIG.

FIG. 3 is a diagram showing an example of frequency allocation of first and second control channel groups.

FIG. 4 is a diagram for explaining an example of spurious wave generation.

[Explanation of symbols]

 1 ... Antenna 2 ... Antenna duplexer (DUP) 3 ... Reception circuit (RX) 4 ... Frequency synthesizer (SYN) 5 ... Transmission circuit (TX) 6, 16, 21 ... A / D converter 7 ... Digital demodulation circuit (DEM) ) 8 ... Error correction code decoding circuit (CH-COD) 9 ... Voice code decoding circuit (SP-COD) 10, 17 ... Switching circuit 11, 19, 22 ... D / A converter 12 ... Receiver amplifier 13 ... Speaker 14 ... Microphone 15 ... Transmitting amplifier 18 ... Digital modulator (MOD) 20 ... Analog voice circuit 30 ... Echo canceller (EC-CAN) 40 ... Control circuit 40a ... PCI determination means 40b ... Control channel capture control means 41 ... Battery 42 ... Power supply Circuit 43 ... Console unit

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masataka Yamashita 21-3-1, Asahigaoka, Hino City, Tokyo 21 Toshiba Communication Technology Co., Ltd.

Claims (1)

[Claims] 1. An analog mode base station using a first control channel group and a dual mode base station using at least a second control channel group having a frequency band different from that of the first control channel group are mixed. In a dual-mode wireless communication device which is used in a service area that is provided as a stand-by state and selects one of the first control channel group and the second control channel group at the time of initial setting and enters a standby state. , Capturing a specific control channel for transmitting capability information in each of the first control channel group and the second control channel group, and indicating the capability of the base station sent from the base station via these specific control channels Capability information receiving means for receiving information respectively, and capability information received by the capability information receiving means are captured to receive this capability information. Determining means for determining whether the arrival via the control channel group is appropriate, and if the determining means determines that it is appropriate, an arbitrary control from the control channel group is performed. Control channel setting to select a channel and shift to the standby state, and if one is judged to be invalid, select any control channel from the other control channel group and shift to the standby state A dual mode wireless communication device comprising: a control unit.