JP2004349875A - Radio relay method and radio relay apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a radio relay method and a radio relay apparatus capable of suppressing deterioration in communication quality due to a self interference in line call control. <P>SOLUTION: This radio relay apparatus RS is provided with a first radio communication section 1A corresponding to a base station, a second radio communication section 1B corresponding to a terminal device, and a relay control unit 2 for performing relay transmission processing from the communication sections 1A, 1B. The control unit 2 is provided with a function for assigning a time slot used in the communication section 1A in response to the line call control of the base station side and a time slot used in the communication section 2B in response to the line call control of the terminal device side to time slots having different numbers. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a wireless relay method used for a communication system such as a PHS using the TDMA method and a wireless relay device using the same.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, a PHS, which is a type of a TDMA wireless communication system, includes a wireless relay device having a relay function. The wireless relay device is installed in an environment where a wireless communication signal of a public channel reaches a window, but does not sufficiently reach a distant place from a window in a building. That is, for example, a wireless relay device installed near a window inside a dwelling unit receives a wireless communication signal of a public channel from a base station connected to a public line network, and converts the wireless communication signal of the public channel into a wireless communication signal of a private channel. To the terminal (mobile device) existing in the building and send the wireless communication signal of the private channel from the terminal to the wireless communication signal of the public channel and send it to the base station outside the building, It enables communication between an indoor terminal and a base station. (Patent Document 1)
A recent wireless relay device for PHS has a wireless communication unit corresponding to the base station side and a wireless communication unit corresponding to the terminal side, and demodulated from a wireless communication signal received by one of the wireless communication units. There is provided a device that performs bidirectional relay by relaying and transmitting received data from another wireless communication unit using a wireless communication signal.
[0003]
FIG. 8 shows a configuration diagram of a time slot in the PHS. As shown in FIG. 8, four time slots for transmission and four time slots for reception (hereinafter referred to as slots) are provided. To increase the number of channels.
[0004]
Correspondingly, even in the radio relay apparatus (relay station), the radio communication unit 1A corresponding to the base station CS receives a slot TS of a section (downstream section) for receiving a radio communication signal transmitted from the base station CS side, and a mobile station. Four slots TS are provided in a section (uplink section) in which data received from the terminal PS is relayed and transmitted by a wireless communication signal, and the wireless communication section 1B corresponding to the terminal PS has a terminal corresponding to the downlink section. There are provided four slots TS for relaying and transmitting the reception data from the base station CS to the terminal PS by radio communication signals, and four slots TS for receiving the radio communication signals from the terminal PS corresponding to the up section. . The numbers 1 to 4 of each slot TS indicate the slot number of the slot.
[0005]
In this radio relay apparatus, a slot used for line call control is set by the radio communication unit 1A on the base station CS side and the radio communication unit 1B on the terminal PS side at the time of circuit switching. At the time of 32 kbps packet communication, one empty slot in each of the two wireless communication units 1A and 1B is used, and at the time of 128 kbps packet communication, all four slots are used.
[0006]
[Patent Document 1]
JP 10-155172 A
[Problems to be solved by the invention]
By the way, in the wireless relay device provided with the above-mentioned two wireless communication units 1A and 1B, the same absolute slot for line call control is used in the wireless communication units 1A and 1B, for example, when the slot number is “1” corresponding to the downlink section. When the slot and the slot with the slot number “4” are set corresponding to the upstream section, for example, the wireless communication signal transmitted at the timing of the slot “1” from the wireless communication unit 1B on the terminal PS side Is received by the wireless communication unit 1A on the base station CS side at the timing of the slot “1”, and this wireless communication signal is a self-interfering wave that interferes with the wireless communication signal transmitted from the base station CS. Become.
[0008]
Similarly, the radio communication signal transmitted from the radio communication unit 1A on the base station CS at the timing of slot “4” is received by the radio communication unit 1B on the terminal PS at the timing of slot “4”. This wireless communication signal becomes a self-interfering wave that interferes with the wireless communication signal transmitted from the terminal device PS. Therefore, there is a problem that a decrease in communication quality cannot be suppressed. In particular, when voice communication is performed, a decrease in communication quality may make the caller feel uncomfortable.
[0009]
The present invention has been made in view of the above points, and an object of the present invention is to provide a wireless relay method and a wireless relay apparatus that can suppress a decrease in communication quality due to self-interference in line call control. .
[0010]
[Means for Solving the Problems]
In order to achieve the above object, according to the first aspect of the present invention, a first wireless communication unit corresponding to a base station and a second wireless communication unit corresponding to a base station are used in a TDMA wireless communication system. When a wireless communication signal from the base station is received by the first wireless communication unit, the received data is relayed and transmitted to the terminal by a wireless communication signal from the second wireless communication unit, And a relay control unit that performs a relay process of relaying the received data to the base station by a wireless communication signal from the first wireless communication unit when the wireless communication signal from the terminal is received by the second wireless communication unit. In the wireless relay method using the provided wireless relay device, the time slot used in the first wireless communication unit corresponding to the line call control on the base station side and the line call control on the terminal side In the second wireless communication unit And a time slot for use, characterized in that assigned to the time slots of different slot number.
[0011]
According to the invention of the wireless relay method of the first aspect, in the line call control, it is possible to suppress a decrease in communication quality due to self-interference and to make a call that does not give a sense of discomfort.
[0012]
In a second aspect of the present invention, a first wireless communication unit corresponding to a base station, a second wireless communication unit corresponding to a terminal, and the base station are used in a TDMA wireless communication system. When receiving the wireless communication signal from the first wireless communication unit, relays the received data to the terminal by wireless communication signal from the second wireless communication unit, and transmits the wireless communication signal from the terminal to the terminal. A relay control unit for performing a relay process of relaying the received data to the base station by a wireless communication signal from the first wireless communication unit when the data is received by the second wireless communication unit; A time slot used by the first wireless communication unit corresponding to the line call control on the office side and a time slot used by the second wireless communication unit corresponding to the line call control on the terminal side. Different slots from each other Characterized in that it comprises a function to be assigned to the No. of time slots to the interface controller.
[0013]
According to the wireless relay device of the second aspect, it is possible to provide a wireless relay device capable of suppressing a decrease in communication quality due to self-interference and enabling a call that does not give a sense of incongruity.
[0014]
According to a third aspect of the present invention, in the second aspect of the present invention, the time slot used by the second wireless communication unit from the base station due to interference during line call control on the base station side. Is assigned as the switching destination time slot, the time slot used in the second wireless communication unit is switched to another time slot, and the time slot used for line call control of the first wireless communication unit is changed to the second time slot. The relay control unit is provided with a function of switching to the time slot used before switching in the wireless communication unit of No. 2.
[0015]
According to the wireless relay device of the third aspect, even if interference occurs on the base station side and the communication quality is degraded, measures can be taken to continue the line call control while maintaining the original communication quality.
[0016]
According to a fourth aspect of the present invention, in the second aspect of the present invention, during the line call control on the side of the base station, the base station uses the second radio communication unit due to interference. Is assigned as the switching destination time slot, the time slot used for the line call control of the first wireless communication unit is the same as the time slot used for the line call control of the second wireless communication unit. The relay control unit has a function of switching to a time slot of a slot number.
[0017]
According to the invention of the wireless relay device of the fourth aspect, when interference occurs on the base station side and the communication quality is degraded, measures to continue the line call control while ensuring the maximum available slots are taken. I can take it.
[0018]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described with reference to embodiments.
[0019]
Hereinafter, an embodiment in which the present invention is applied to a wireless relay device (relay station) RS used in a wireless communication system conforming to the second generation cordless telephone system standard (RCR STD-28 4.0 version, published by The Radio Industries and Businesses Association) The form will be described. However, the configuration and operation of the base station CS and the terminal PS as a mobile station, and the basic operation of the radio relay device RS are conventionally well-known as specified in the above-mentioned standard, and therefore description thereof is omitted.
[0020]
(Embodiment)
FIG. 1 shows a block diagram of a wireless relay device RS of the present embodiment, and FIG. 2 also shows an external structure. As shown in FIG. 1, the wireless relay device RS includes a first wireless communication unit 1A that wirelessly communicates with a public base station CS and a second wireless communication unit that wirelessly communicates with a terminal PS such as a PHS terminal that supports packet communication. Wireless communication unit 1B, a relay control unit 2 that controls the first and second wireless communication units 1A and 1B to perform a process for relaying, and receives power supply from a commercial power supply and controls the operation power of each unit. The power supply unit 3 to be created is provided as a basic configuration. The first and second wireless communication units 1A and 1B have antennas 4A and 4B for transmitting and receiving wireless communication signals to and from the base station CS and the terminal PS, respectively. A transmission / reception unit (not shown) and a modem (not shown) for demodulating data from a received wireless communication signal and performing modulation for relaying and transmitting the demodulated reception data as transmission data are included.
[0021]
The relay control unit 2 includes a peripheral circuit such as a CPU and a memory, and executes the above-described relay processing and various processing described later by executing a program mounted on the memory by the CPU.
[0022]
As shown in FIG. 2, the wireless relay device RS has a housing 10 made of synthetic resin, and the antennas 4A of the first and second wireless communication units 1A and 1B are provided at both ends of the housing 10 in the widthwise direction in the longitudinal direction. , 4B are stored.
[0023]
Here, as described in the related art, when transmission and reception are performed in the same slot by the two wireless communication units 1A and 1B, not only wireless communication signals of frequency channels used for transmission but also wireless channels of frequency channels other than the frequency channels are used. There is a problem that self-interference also occurs in a communication signal, and a decrease in communication quality cannot be suppressed. In particular, when voice communication is performed, a decrease in communication quality causes the caller to feel uncomfortable.
[0024]
Therefore, in the present embodiment, in the line call control, in order to prevent the communication quality from deteriorating due to the above-described self-interference, the relay control unit 2 uses the slot allocation processing of the wireless communication unit 1B on the terminal PS side in the line call control. Is performed as shown in the flowchart of FIG.
[0025]
In this case, first, in step S1, the number of the slot used for line call control of the radio communication unit 1A on the base station CS side is checked, and if the number of the slot (absolute slot) used in the radio communication unit 1A is "1", If the slot used in the wireless communication unit 1B on the terminal PS side is a slot (absolute slot) other than the number "1" and the slot number used in the wireless communication unit 1A is "2" as in step S21, the process proceeds to step S21. If the slot used by the wireless communication unit 1B on the terminal PS side is a slot other than the number “2” as in S22, and if the absolute slot number used by the wireless communication unit 1A is “3”, as in step S23 The slot used by the wireless communication unit 1B on the terminal PS side is a slot other than the number “3”, and the absolute slot number used by the wireless communication unit 1A is “4”. In assigning the slots to be used by the wireless communication unit 1B of the terminal PS side as in step S24 to the slot other than the number "4".
[0026]
This state is shown in FIG. In the case of FIG. 4, the slot number “1” is used for the packet communication of 32 kbps using the slot. However, in the call control in the circuit switching, the radio communication of the radio relay apparatus RS corresponding to the base station CS is performed. An absolute slot having a slot number of "2" is assigned to the unit 1A, and an absolute slot having a slot number of "3" is assigned to the wireless communication unit 1B corresponding to the terminal PS. By using the same slot number, it is possible to prevent a decrease in communication quality due to self-interference.
[0027]
By the way, when interference occurs during line call control and reception level degradation or reception quality degradation occurs, the base station CS specifies a TCH (traffic channel) switching destination slot. When this designation is made, the relay control unit 2 starts the TCH switching process of the following line call control.
[0028]
As the TCH switching process, there are the following two methods.
[0029]
Example 1
In this example, as shown in the flowchart of FIG. 5, during line call control (step S10), interference occurs, interference occurs in line call control, and the base station CS allocates a TCH switching destination slot. If there is, in step S11, it is checked whether or not the slot matches the slot being used in the wireless communication unit 1B on the terminal PS side. If not, the TCH switching in the wireless communication unit 1A of the base station CS is performed. This is performed according to the assigned slot (step S12). The slot used by the wireless communication unit 1B on the terminal PS is switched to another slot, and then the slot used by the wireless communication unit 1A on the base station CS is switched to the slot used by the terminal PS before switching. That is, as shown in FIG. 6, for example, the slot with the number “3” used in the wireless communication unit 1A on the base station CS side corresponding to the TCH in the line call control is switched to the TCH from the base station CS due to interference. Is assigned to the slot with the number “1”, the relay control unit 2 first sets the wireless communication unit since the slot with the number “1” is used by the wireless communication unit 1B on the terminal PS side. The slot being used in 1B is switched to the empty slot “4”, and the slot “1” is temporarily made an empty slot. The process of switching the empty slot “1” from the slot “3” as the TCH slot of the line call control used in the wireless communication unit 1A is performed. As a result, communication quality of the base station CS during line call control can be ensured.
[0030]
Example 2
In Example 1, if the switching slot of the TCH allocated from the base station CS is a slot used by the terminal PS, after switching the slot used by the terminal PS to another empty slot, the terminal Although the slot used by the mobile station PS is switched to the slot to which the TCH of the base station CS is switched, the line call control on the base station CS side is performed as shown in the flowchart of FIG. Is switched to the slot having the same number as the slot used in the line call control of the terminal PS (step S13). Other processes are the same as those in the first embodiment.
[0031]
In the case of this example, since the slots used on the terminal PS side and the base station CS side have the same number, there is an advantage that the maximum number of empty slots that can be used for packet switching and circuit switching can be secured. . In other words, when switching to a slot with a different number, the number of available empty slots is limited by the later slot in time series, so that the slots cannot be used effectively.
[0032]
【The invention's effect】
According to the first aspect of the present invention, since the time slots used in the line call control on the base station side and the terminal side are time slots having different slot numbers, it is possible to prevent a decrease in communication quality due to self-interference.
[0033]
The wireless relay apparatus according to the second aspect of the present invention uses a time slot by allocating a time slot used for circuit call control on the base station side and the terminal side to a different slot number, thereby improving communication quality due to self-interference. It is possible to provide a wireless relay device in which a decrease is prevented.
[0034]
According to the third aspect of the present invention, measures can be taken to maintain the original communication quality and continue the line call control even when the communication quality is degraded due to the occurrence of interference at the base station.
[0035]
According to the fourth aspect of the invention, when interference occurs on the base station side and the communication quality is degraded, it is possible to take measures to continue the line call control while ensuring the maximum available slots.
[Brief description of the drawings]
FIG. 1 is a circuit configuration diagram of a wireless relay device of an embodiment.
FIG. 2 is a perspective view showing an appearance of the wireless relay device of the embodiment.
FIG. 3 is a flowchart illustrating an operation of slot assignment in circuit call control according to the embodiment.
FIG. 4 is an explanatory diagram of slot assignment in circuit call control according to the embodiment.
FIG. 5 is a flowchart for explaining the operation of Example 1 of slot assignment when interference occurs in a base station during line call control according to the embodiment;
FIG. 6 is an explanatory diagram of slot allocation in Example 1 of slot allocation when interference occurs in a base station during line call control according to the embodiment;
FIG. 7 is a flowchart for explaining the operation of Example 2 of slot assignment when interference occurs in the base station during line call control according to the embodiment;
FIG. 8 is an explanatory diagram of a problem of a conventional wireless relay device.
[Explanation of symbols]
RS wireless relay device 1A, 1B wireless communication unit 2 relay control unit 3 power supply unit 4A, 4B antenna

Claims (4)

A first wireless communication unit corresponding to a base station, a second wireless communication unit corresponding to a terminal, and a wireless communication signal from the base station are used in a TDMA wireless communication system. When received by the communication unit, the received data is relayed and transmitted to the terminal by a wireless communication signal from the second wireless communication unit, and when the wireless communication signal from the terminal is received by the second wireless communication unit, the received data is received. And a relay control unit that performs a relay process of relaying and transmitting data to the base station from the first wireless communication unit by a wireless communication signal.
A time slot used by the first radio communication unit corresponding to the line call control on the base station side, and a time slot used by the second radio communication unit corresponding to the line call control on the terminal side Are assigned to time slots having different slot numbers from each other. A first wireless communication unit corresponding to a base station, a second wireless communication unit corresponding to a terminal, and a wireless communication signal from the base station are used in a TDMA wireless communication system. When received by the communication unit, the received data is relayed and transmitted to the terminal by a wireless communication signal from the second wireless communication unit, and when the wireless communication signal from the terminal is received by the second wireless communication unit, the received data is received. A relay control unit that performs a relay process of relaying and transmitting data to the base station from the first wireless communication unit using a wireless communication signal,
A time slot used by the first radio communication unit corresponding to the line call control on the base station side, and a time slot used by the second radio communication unit corresponding to the line call control on the terminal side A function of allocating to the time slots having different slot numbers from each other in the relay control unit. During the line call control on the base station side, if a time slot used by the second wireless communication unit is assigned as a switching destination time slot by the base station due to interference, the time used by the second wireless communication unit is changed. A function of switching a slot to another time slot and switching a time slot used for line call control of the first wireless communication unit to the time slot used before switching in the second wireless communication unit; The wireless relay device according to claim 2, wherein the wireless relay device is provided in a control unit. During the line call control on the base station side, when a time slot being used in the second wireless communication unit is assigned as a switching destination time slot from the base station due to interference, the first wireless communication unit The relay control unit has a function of switching a time slot used for line call control to a time slot having the same slot number as a time slot used for line call control of the second wireless communication unit. The wireless relay device according to claim 2.

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