JP3594393B2 - Wireless relay device - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a wireless relay device that relays wireless communication between a base station and a mobile station using a TDMA / TDD scheme that performs communication by time division multiple access and time division bidirectional transmission.
[0002]
[Prior art]
Time division multiple access TDMA (Time Division Multiple Access) is a method in which a radio frequency is time-divided, a specific time zone is allocated to a user, and communication is performed in the allocated time zone. (Time Division Duplex) is to use the same radio frequency in a time-division manner between transmission and reception, and when accommodating a plurality of mobile stations, a plurality of channels are used. FIG. 3 shows a configuration in which there are three mobile stations, and the public base station 21 can be connected to three mobile stations 31, 32, and 33 at the same time. The mobile station 31 performs transmission and reception in slot # 1 designated by the public base station 21. When receiving the radio wave transmitted by the public base station 21 in slot # 1, the mobile station 31 transmits the radio wave to the public base station 21 in slot # 1 in synchronization with the reception timing of the public base station 21. Similarly, the other mobile stations 32 and 33 transmit and receive using the slots # 3 and # 4, respectively, in synchronization with the transmission and reception timing of the public base station 21. In this case, slots # 1, # 3, and # 4 are used for a communication channel, slot # 2 is used for a control channel, and mobile stations 31, 32, and 33 are intermittently transmitted from base station 21 during standby. Incoming control notification information (LCCH).
[0003]
[Problems to be solved by the invention]
In the above-mentioned conventional mobile communication, when the distance between the base station and the mobile station is long, radio waves may not reach sufficiently, and a wireless relay device called a home antenna (hereinafter referred to as a home antenna) is provided between the base station and the mobile station. , Which may be simply referred to as a repeater) for smooth wireless communication connection. The problem here is that the repeater must synchronize with both the base station and the mobile station, and when the mobile station waits, the repeater uses the control channel from the base station to transmit intermittently in 100 ms. It is defined that the communication control signal (LCCH) received is transmitted to the mobile station at a longer fixed cycle. For this reason, there arises a problem of how to synchronize a fixed period of 100 ms output from the base station with a fixed period longer than that output from the repeater and correct the same.
[0004]
The present invention solves such a conventional problem, and uses a TDMA / TDD system for performing communication by time division multiple access and time division bidirectional transmission, and performs wireless communication between a base station and a mobile station. When transmitting communication control information to a mobile station during standby of the mobile station, the wireless relay apparatus that relays can reliably synchronize between the base station and the mobile station even when using a different cycle from the base station. It is an object to provide a wireless relay device.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a wireless relay device that relays wireless communication between a base station and a mobile station using a TDMA / TDD method, wherein the wireless relay device includes a wireless unit, a CPU, A base station signal processing unit, a mobile station signal processing unit, and a synchronization establishment correction unit, when the radio unit receives a communication control signal transmitted from the base station, the synchronization establishment correction unit, After receiving the synchronization establishment request from the CPU, an interrupt signal from the mobile station signal processing unit is detected, and a timing signal is output to the base station processing signal unit. Is the least common multiple of the cycle of the communication control signal output to the wireless relay apparatus and the cycle of the communication control signal output to the wireless relay apparatus by the mobile station , whereby the base station When Synchronization between mobile stations can be ensured.
[0006]
BEST MODE FOR CARRYING OUT THE INVENTION
An invention according to claim 1 of the present invention uses a TDMA / TDD system for performing communication by time division multiple access and time division bidirectional transmission, and relays wireless communication between a base station and a mobile station. In, when the mobile station is in a standby state, the radio relay apparatus receives a communication control signal transmitted from the base station at a fixed cycle, when transmitting to the mobile station at a fixed cycle longer than the fixed cycle of the base station, A wireless relay device comprising means for performing synchronization correction for each time interval of the least common multiple of a fixed period in a base station and a fixed period in a wireless relay device. Synchronization between them can be ensured.
[0007]
According to a second aspect of the present invention, in the wireless relay device according to the first aspect, when the mobile station shifts from the standby state to the talk state, the call control in which the wireless relay device is transmitted from the base station at a constant period. When a signal is received and transmitted to the mobile station at the same fixed cycle, the mobile station is provided with a means for performing synchronization correction at the fixed cycle, so that even during a call state of the mobile station, synchronization between the base station and the mobile station is established. Can be taken reliably.
[0008]
(Embodiment)
FIG. 1 shows a schematic configuration of a wireless relay device, that is, a repeater according to an embodiment of the present invention. In FIG. 1, A transmits a communication control signal at a period of 100 ms, and a base station transmits a communication control signal at a period of 5 ms. B receives a communication control signal at a period of 100 ms from the base station A and transmits it at a period of 150 ms. A repeater that transmits to the mobile station C, and C is a mobile station that receives a communication control signal from the repeater B at a period of 150 ms. In the repeater B, 1 is a power supply unit, 2 is a CPU, 3 is a base station signal processing unit, 4 is a synchronization establishment / correction unit, 5 is a mobile station signal processing unit, and 6 is a radio unit equipped with a PLL circuit as synchronization means. , 7 are transmitting and receiving antennas.
[0009]
Next, the operation of the above embodiment will be described with reference to the timing chart of FIG. In FIG. 2A, when the mobile station C waits, the repeater B, which has received the communication control signal intermittently transmitted from the base station A in 100 ms by the antenna 7, uses the preamble and the preamble in the communication control signal. The unique word is demodulated to recognize that it is a communication control signal. When the relay station B transmits this communication control signal to the mobile station C, the synchronization establishment / correction unit 4 receives a synchronization establishment request from the CPU 2 and immediately after that, the mobile station signal processing unit 5 generates an interrupt signal. Detects the signal and generates a timing signal synchronized with the signal, and transmits this signal to the base station signal processing unit 3. This timing signal needs to be output at any one of the cycle of the communication control signal output from the base station A, 100 ms, and the cycle of the repeater B outputting the communication control signal to the mobile station C, 150 ms. , Every 100 ms, the circuit configuration in the synchronization establishment / correction unit 4 becomes complicated, and every 150 ms, the synchronization may be lost. Therefore, the synchronization establishment / correction unit 4 outputs a synchronization correction signal to the base station signal processing unit 3 every 300 ms period that is the least common multiple of both. In the case of a 300 ms cycle, the variation of the clock cycle between the base station A and the mobile station C is specified to be ± 3 ppm, respectively, so that the maximum is 6 ppm, which is 1.8 μs for the 300 ms cycle. Since this is within one symbol (about 2.6 μs) of the information amount, it is appropriate as the period of the synchronization correction signal. As a result, the synchronization of the base station signal processing unit 3 coincides with the synchronization of the mobile station signal processing unit 5, and synchronization establishment and correction between the base station A and the mobile station C via the repeater B become possible. .
[0010]
In this way, after the synchronization at the time of standby of the mobile station C is established, the call is connected by a call request from the mobile station C using the control channel or by an incoming call notification from the base station A. When the communication channel is switched to the communication channel, a communication control signal is transmitted from the base station A at the same period of 5 ms as the communication signal, as shown in FIG. In the repeater B, the radio unit 6 demodulates the call control signal and transmits it to the synchronization establishment / correction unit 4. The synchronization establishment / correction unit 4 generates a timing signal having the same period as the 5 ms period from the base station A, and sends this to the mobile station signal processing unit 5. In response to this, the mobile station signal processing unit 5 transmits a call control signal to the mobile station C at a period of 5 ms. As a result, even during a call, synchronization establishment and correction between the base station A and the mobile station C via the repeater B can be performed.
[0011]
As described above, in the above embodiment, when the mobile station C waits, the relay B receives the communication control signal transmitted from the base station A at a period of 100 ms and transmits the communication control signal to the mobile station C at a period of 150 ms. In this case, the synchronization establishment / correction unit 4 generates a timing signal so as to correct the synchronization every 300 ms, which is the least common multiple of 100 ms and 150 ms. Synchronization between the station A and the mobile station C can be ensured. When the mobile station C shifts from a standby state to a call state, the repeater B receives a call control signal transmitted from the base station A at a period of 5 ms and transmits the signal to the mobile station C at the same period of 5 ms. At this time, the synchronization establishment / correction unit 4 generates a timing signal so as to correct the synchronization at the same interval of every 5 ms, so that the synchronization between the base station A and the mobile station C is ensured even in the communication state of the mobile station C. Can be taken.
[0012]
【The invention's effect】
As described above, the radio relay apparatus according to the present invention can transmit a communication control information to a mobile station when the mobile station is on standby, even if a different cycle from the base station is used. Since the means for correcting the synchronization is provided for each time interval of the least common multiple of the predetermined period in the above, synchronization between the base station and the mobile station can be ensured.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a schematic configuration of a wireless relay device according to an embodiment of the present invention; FIG. 2 (a) is a timing diagram of a communication control signal when the device waits for a mobile station; FIG. FIG. 3 is a timing chart of a call control signal when a station shifts from a standby state to a call state. FIG. 3 is a schematic diagram showing a conventional TDMA / TDD system.
A base station B repeater C mobile station 1 power supply unit 2 CPU
3 base station signal processing unit 4 synchronization establishment / correction unit 5 mobile station signal processing unit 6 radio unit 7 antenna

Claims (2)

In a wireless relay device that relays wireless communication between a base station and a mobile station using a TDMA / TDD system that performs communication by time division multiple access and time division bidirectional transmission,
The wireless relay device includes a wireless unit, a CPU, a base station signal processing unit, a mobile station signal processing unit, and a synchronization establishment correction unit,
When the wireless unit receives a communication control signal transmitted from the base station, the synchronization establishment correction unit detects an interruption signal from the mobile station signal processing unit after receiving a synchronization establishment request from the CPU. And outputting a timing signal to the base station processing signal section,
The output cycle of the timing signal is a least common multiple of a cycle of a communication control signal that the base station outputs to the wireless relay apparatus and a cycle of a communication control signal that the mobile station outputs to the wireless relay apparatus.
A wireless relay device characterized by the above-mentioned . When the synchronization establishment correcting unit receives a call control signal transmitted from the base station at a fixed period and transmits it to the mobile station at the same constant period when the mobile station shifts from the standby state to the call state, 2. The wireless relay apparatus according to claim 1, wherein synchronization correction is performed at regular intervals.

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