JP2004186713A - Communication control method and communication apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce a loss caused by a transmission signal branched to another communication section by shutting off a signal input to the communication section adopting another communication system in dual mode communication wherein transmission and reception are performed by a plurality of communication systems whose frequency bands are close to each other. <P>SOLUTION: A dual mode communication terminal includes: a duplexer 12; an RF switch 13; a W-CDMA communication section 14; a PHS communication section 15; and a control/HMI section 16. When discriminating a signal received via the duplexer 12 to be the signal arrived in the W-CDMA side, the control/HMI section 16 stops a system of the PHS communication section 15, switches the RF switch 13 to the W-CDMA communication section 14, informs the W-CDMA communication section 14 of a communication permission, and the W-CDMA communication section 14 whose communication is permitted starts processing required for a speech. Further, when the signal arrives in the PHS side, the control/HMI section 16 stops the system of the W-CDMA communication section 14 and informs the PHS communication section 15 of the communication permission. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a communication control method and a communication device, and more particularly, to a communication control method and a communication device for performing communication in a dual mode using a PHS (Personal Handyphone System) method and an IMT2000 (International Mobile Telecommunications 2000) method.
[0002]
[Prior art]
In the field of mobile communication, a PHS system that can easily realize mobile communication has been put to practical use. In recent years, a mobile communication system called IMT2000 capable of high-speed communication has been spotlighted. In the above PHS system, communication is performed by the TDMA-TDD method and radio waves in the 1.9 GHz band are used. Further, in the IMT2000 system, a W-CDMA system, which is one of CDMA (Code Division Multiple Access) -FDD (Frequency Division Duplex) system, has been put into practical use and uses a 2 GHz band radio wave and moves in a low frequency band. Transmission is performed from the mobile terminal to the base station, and a signal is transmitted from the base station to the mobile terminal at a high frequency. In general, a duplexer is used in the FDD system to combine or separate transmission and reception signals. The FDD (duplex) method is one of communication methods between a base station and a terminal used in a mobile communication system, and includes an uplink direction (terminal → base station) and a downlink direction (base station → terminal). By using different frequencies for each communication, bidirectional communication is realized.
[0003]
Here, as a dual mode communication terminal capable of simultaneously performing a plurality of communications, a communication terminal capable of performing dual mode communication with a PDC (Personal Digital Cellular) and a PHS (hereinafter, a dual mode communication terminal) is used. Has been put to practical use. At this time, the PDC uses an 800 MHz band radio wave. In a dual mode communication terminal, both radio waves can be simultaneously received so as to be able to receive both radio waves from the PDC side and the PHS side.
[0004]
As a conventional dual-mode communication terminal, in a communication device including a plurality of wireless communication units, by controlling the PDC-side transmission unit and the PHS-side transmission unit not to transmit at the same time, a plurality of wireless communication units are controlled. There is disclosed an apparatus that can suppress generation of unnecessary radio waves due to intermodulation distortion generated when used simultaneously. (For example, see Patent Document 1)
[0005]
FIG. 6 is a block diagram for explaining a configuration example of a conventional dual mode communication terminal. In the figure, 21 and 26 are antennas, 22 is a duplexer, 23 is a PDC unit, 24 is a PHS unit, and 25 is a control / HMI. The PDC unit 23 includes a receiving unit 231 and a transmitting unit 232, and the PHS unit 24 includes a receiving unit 241 and a transmitting unit 242.
[0006]
In FIG. 6, a signal received by an antenna 21 is separated by a duplexer 22 into an 800 MHz band signal and a 1.9 GHz band signal. The 800 MHz band signal is input to the receiving unit 231 in the PDC unit 23, and the 1.9 GHz band signal is input to the receiving unit 241 of the PHS unit 24. The control / HMI unit 25 controls transmission and reception of PHS and PDC. This dual mode communication terminal can receive an incoming signal in both the PHS and PDC receiving units 231 and 241 during standby, so that it is possible to receive an incoming call by calling any of the PHS and PDC telephone numbers. is there. During a PDC call, a signal in the 800 MHz band is transmitted from the transmission unit 232 of the PDC unit 23, and a radio wave is transmitted from the antenna 21 through the duplexer 22. During a PHS call, a signal in the 1900 MHz band is transmitted from the transmission unit 242 of the PHS unit 24, and a radio wave is transmitted from the antenna 21 through the duplexer 22. The PDC unit 23 can also receive a signal from the antenna 26.
[0007]
[Patent Document 1]
Japanese Patent Application Laid-Open No. 2000-29559
[Problems to be solved by the invention]
However, when trying to realize a dual mode communication terminal of the PHS system and the IMT2000 system (for example, W-CDMA or the like) by the invention described in Patent Document 1, the frequency bands used for the PHS system and the IMT2000 system are close to each other. Therefore, there is a problem that signal separation by the duplexer becomes difficult. In particular, since the transmitting side of the IMT2000 system has a frequency band closer to the frequency band of the PHS system, signal separation becomes difficult. If the signal is branched without using the duplexer, the received signal is guided to both the PHS and IMT2000 communication units, so that the loss increases and the reception quality deteriorates. Further, at the time of transmission, one transmission signal is branched to another communication unit, so that the transmission output is greatly reduced.
[0009]
The present invention has been made in view of the above situation, and in a dual mode communication terminal that performs transmission / reception using a plurality of communication systems using adjacent frequency bands, when transmitting in one communication system, the other By cutting off the signal input to the communication unit of the system, the signal loss due to the transmission signal being branched to the other communication unit is reduced, and the transmission signal does not affect the operation of the other communication unit. It is intended to prevent adverse effects such as occurrence.
[0010]
[Means for Solving the Problems]
A first technical means for achieving the above object is a communication control method for controlling a communication device having a plurality of communication units having different use frequency bands, wherein a plurality of communication signals corresponding to the use frequency bands can be received. And a step of interrupting the input of a communication signal to the other communication unit when transmitting from one communication unit in response to the received communication signal. is there.
[0011]
Further, the second technical means is characterized in that, in the first technical means, after the transmission process from the one communication unit is completed, the state shifts to the standby state.
[0012]
According to the first and second technical means, in a dual mode communication terminal that performs transmission and reception in a close frequency band, a plurality of different communication signals can be simultaneously received in a standby mode, and one communication unit transmits. When the signal input to the other communication unit is interrupted, the signal loss due to the transmission signal being branched to the other communication unit can be reduced, and the transmission signal gives the operation of the other communication unit. The effect can be reduced.
[0013]
Further, a third technical means includes: a plurality of communication units in which at least one of the communication systems is FDD and the operating frequency bands are close to each other; a duplexer for combining or separating communication signals during communication by the FDD; And a switch for connecting any one of the plurality of communication units to the duplexer before combining the communication signals.
[0014]
Further, a fourth technical means is the third technical means, wherein the switch cuts off an input of a communication signal to the other communication part when one of the communication parts is transmitting. Things.
Further, in the fifth technical means, in the third or fourth technical means, even if a non-priority communication unit is communicating when there is a priority communication unit, the fifth technical means forcibly complies with a communication request of the priority communication unit. The switch is switched, the switch is switched again after the communication of the priority communication unit is completed, and the communication of the non-priority communication unit is restarted.
[0015]
According to the third and fourth technical means, before the communication unit on the FDD side combines the communication signals with the duplexer, the communication unit on the FDD side is switched and connected to the duplexer by a switch. The transmission signal and the reception signal are separated from each other, so that the signal attenuation with respect to the other communication unit can be reduced. For this reason, spurious from two communication parts can be reduced. Further, with such a configuration, it is possible to perform standby so that reception can be performed simultaneously by a plurality of communication schemes using adjacent frequency bands. At this time, by appropriately setting the filter band of the duplexer, it is possible to omit a band-pass filter required in the other communication unit.
Further, according to the fifth technical means, communication can be performed without interrupting communication of the priority communication unit.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 is a block diagram for explaining a configuration example of a dual mode communication terminal according to an embodiment of the present invention. In the figure, 11 is an antenna, 12 is a duplexer, 13 is an RF switch, and 14 is W-CDMA communication. , 15 is a PHS communication unit, 16 is a control / HMI unit, the duplexer 12 has band pass filters (hereinafter, referred to as BPFs) 121 and 122, and the W-CDMA communication unit 14 has a transmission unit 141 and a reception unit 142. The PHS communication unit 15 has a transmission unit 151 and a reception unit 152. The W-CDMA communication unit 14 according to the present embodiment uses, as a representative example, the W-CDMA system, which is one of the CDMA-FDD systems in the above-described IMT2000, but uses an IMT2000 using a frequency band near the 2 GHz band. Can also be applied to other communication methods included in. In addition, the present invention is not limited to the above-mentioned frequency band (1.9 GHz band, 2 GHz band), but is preferably used for a dual mode communication terminal that performs transmission and reception by a plurality of communication systems using adjacent frequency bands. It is.
[0017]
FIG. 2 is a diagram showing an example of the frequency characteristics of the BPFs 121 and 122 shown in FIG. The BPF 121 has a characteristic that a transmission band of the PHS and a transmission band of the IMT2000-FDD become a pass band. Further, the BPF 122 has a characteristic that the reception band of the IMT2000-FDD becomes a pass band.
[0018]
In FIG. 1, a signal received by an antenna 11 is guided to a duplexer 12. The signal is split into two in the duplexer 12 and input to the BPFs 121 and 122, respectively. Each of the BPFs 121 and 122 has a frequency characteristic shown in FIG. With the above configuration, the PHS reception signal is guided to the RF switch 13 connected to the BPF 121, and the W-CDMA reception signal is guided to the W-CDMA communication unit 14 connected to the BPF 122. At this time, the received signal is not guided to each of the other communication units because the BPF becomes a stop band. According to this configuration, a BPF (not shown) normally provided in the PHS communication unit 15 can be omitted. The RF switch 13 is controlled by a control signal from the control / HMI unit 16. As the RF switch 13, an SPDT switch shown in FIG.
[0019]
FIG. 3 is a diagram illustrating an example of a circuit configuration of the RF switch 13.
In FIG. 3, a signal input / output to / from the terminal P1 can be switched to the terminal P2 or P3 by a control signal connected to the VC terminal. In the SPDT switch of this example, when one of the two terminals P2 and P3 is in the passing state, the other terminal is in the open state, and no signal flows and loss is small. That is, the outer terminal is turned off. The RF switch 13 is switched by a control signal connected to the VC terminal, and the PHS reception signal is guided to the PHS communication unit 15. Therefore, it is possible to simultaneously stand by both the W-CDMA and the PHS by guiding the necessary reception signals to the W-CDMA communication unit 14 and the PHS communication unit 15, respectively.
[0020]
The control / HMI unit 16 controls transmission and reception of the W-CDMA communication unit 14 and the PHS communication unit 15. During a PHS call, a signal in the 1900 MHz band is transmitted from the transmission unit 151 in the PHS communication unit 15, and a radio wave is transmitted from the antenna 11 through the RF switch 13 and the duplexer 12. Also, during a W-CDMA call, a transmission signal is transmitted from a transmission unit 141 in the W-CDMA communication unit 14. At this time, the RF switch 13 is switched by a control signal from the control / HMI unit 16, and a transmission signal passing through the RF switch 13 is transmitted from the antenna 11 through the duplexer 12.
[0021]
According to the present invention, before the communication unit on the W-CDMA side combines the communication signals with the duplexer, the communication unit on the W-CDMA side is switched to the duplexer by the switch and connected, so that the transmission during the W-CDMA communication is performed by the duplexer. The signal and the received signal are separated from each other, so that the signal attenuation with respect to the other communication unit can be reduced. Further, with such a configuration, it is possible to perform standby so that reception can be performed simultaneously by a plurality of communication schemes using adjacent frequency bands. Further, spurious from two communication units can be reduced. Further, by appropriately setting the filter band of the duplexer, it is possible to omit a band pass filter required in the other communication unit.
[0022]
FIG. 4 is a diagram illustrating an example of a state transition of the dual mode communication terminal according to the present invention. Under the control from the control / HMI unit 16, in an environment where both W-CDMA and PHS do not require communication, the RF switch 13 is switched so that a signal flows to the PHS side, and the PHS communication unit 15 and the W-CDMA communication unit 14 Each is set to a receiving state, and enters a dual standby state (S1) for intermittently receiving signals from the respective base stations of W-CDMA and PHS and monitoring whether there is an incoming call to the own station. Note that, even in an environment where one radio wave cannot be received, the W-CDMA and the PHS each perform the other one of the receiving operations and are in a standby state (S1). In the dual standby state (S1), when an incoming call arrives at either the W-CDMA or PHS system, the incoming system transitions from the standby state to the communication state. At this time, the other system is set as a system stop state in which transmission / reception is stopped from the standby state, and transmission / reception does not occur (S2 or S3), so that one system does not affect the other system. . Here, after the communication is performed in S2 or S3, the process shifts to the standby state of S1 again. Thus, the processing of S1 → S2 or S3 → S1 is repeated. The actual states of the communication units 14 and 15 in the system stop state can take various modes. For example, it is possible to completely turn off the power, or to take a state where synchronization with the base station is not maintained or a state where only reception is performed and transmission is not performed.
[0023]
FIG. 5 is a diagram for explaining a processing flow when there is an incoming call in the W-CDMA communication unit 14. First, when the control / HMI unit 16 determines that there is an incoming W-CDMA call, the system stops the PHS communication unit 15 (step S11), and switches the RF switch 13 to the W-CDMA communication unit 14 (step S12). Then, the communication permission is notified to the W-CDMA communication unit 14 (step S13). Next, the W-CDMA communication unit 14 permitted to communicate starts processing necessary for a call. On the other hand, when there is an incoming call on the PHS side, a process is performed in which the PHS and the W-CDMA are exchanged in steps S11 to S13 except that step S12 does not occur. That is, when there is an incoming call on the PHS side, the control / HMI unit 16 performs a system stop process of the W-CDMA communication unit 14, and thereafter notifies the PHS communication unit 15 of communication permission.
[0024]
As a method of switching the RF switch 13, another switching method can be considered. For example, when the communication of the W-CDMA communication unit 14 is prioritized over the communication of the PHS communication unit 15, the W-CDMA communication unit 14 is in a standby state while the PHS communication unit 15 is communicating, and the W-CDMA communication unit 14 When an incoming call is received or periodic location registration is performed, the RF switch 13 is forcibly switched, and the W-CDMA communication unit 14 performs communication. Meanwhile, the PHS communication unit 15 is temporarily suspended. After the W-CDMA communication unit 14 completes the necessary communication, the RF switch 13 is switched again, and the communication of the PHS communication unit 15 is restarted. The time interval for switch switching is preferably a time interval at which the PHS communication unit 15 can resume communication, but a method of switching to the W-CDMA communication unit 14 only at a time interval of about 1 ms when the W-CDMA communication unit 14 performs preamble transmission If there is, there is a method of switching to the W-CDMA communication unit 14 for a time interval of several hundred ms or more from the transmission of the preamble to the transmission of the RACH message part. Various modes are conceivable for the communication suspension state of the PHS communication unit 15. For example, a method in which only the PHS transmission unit 151 does not output a signal to prevent spurious generation and continue reception of the PHS reception unit 152 is adopted. Is also possible.
[0025]
According to the present invention, in a dual mode communication terminal that performs transmission and reception in a close frequency band, it is possible to simultaneously receive a plurality of different communication signals during standby, and when one of the communication units transmits, a signal to the other communication unit is transmitted. By blocking the input, it is possible to reduce the signal loss due to the transmission signal being branched to the other communication unit, and to reduce the influence of the transmission signal on the operation of the other communication unit.
[0026]
By performing the operations described above, both the PHS and the W-CDMA are simultaneously on standby, and each communication unit can perform reliable and high-quality communication with respect to other communication units by switching the RF switch 13 without any adverse effect. . Here, it goes without saying that the present invention can be applied in various ways according to the embodiment.
[0027]
【The invention's effect】
According to the present invention, in dual mode communication in which transmission and reception are performed by a plurality of communication systems using adjacent frequency bands, by transmitting a signal in one communication system, a signal input to a communication unit of the other communication system is blocked. In addition, it is possible to reduce the signal loss caused by the transmission signal being branched to the other communication unit, and to prevent the transmission signal from affecting the operation of the other communication unit.
[Brief description of the drawings]
FIG. 1 is a block diagram illustrating a configuration example of a dual mode communication terminal according to an embodiment of the present invention.
FIG. 2 is a diagram illustrating an example of a frequency characteristic of the BPF illustrated in FIG. 1;
FIG. 3 is a diagram illustrating an example of a circuit configuration of an RF switch.
FIG. 4 is a diagram illustrating an example of a state transition of a dual mode communication terminal according to the present invention.
FIG. 5 is a diagram illustrating a processing flow when an incoming call is received in a W-CDMA communication unit.
FIG. 6 is a block diagram illustrating a configuration example of a conventional dual mode communication terminal.
[Explanation of symbols]
11, 21, 26: Antenna, 12, 22, Duplexer, 13: RF switch, 14: W-CDMA communication unit, 15: PHS communication unit, 16, 25: Control / HMI unit, 23: PDC unit, 24: PHS , 121, 122... BPF, 141... W-CDMA transmitting unit, 142... W-CDMA receiving unit, 151. PHS receiver, 242 ... PHS transmitter.

Claims (5)

In a communication control method for controlling a communication device having a plurality of communication units having different use frequency bands, a step of waiting so that a plurality of communication signals corresponding to a use frequency band can be received; Interrupting the input of a communication signal to the other communication unit when transmitting from one communication unit in response to the communication control method. A communication control method, wherein, after the transmission process from the one communication unit is completed, the process shifts to the standby state. A plurality of communication units in which at least one of the communication systems is a duplex system and use frequency bands are close to each other; a duplexer for combining or separating communication signals during communication by the duplex system; and combining the communication signals with the duplexer Switching means for switching and connecting any one of the plurality of communication units to the duplexer before performing the communication. The communication device according to claim 3, wherein the switching unit cuts off input of a communication signal to the other communication unit when one communication unit is transmitting. The switching means forcibly switches a switch to the other communication unit when one communication unit communicates while the other communication unit communicates, and returns the switch to its original state after the end of the communication. The communication device according to 3 or 4.

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