JPH0624332B2 - Wireless relay station in TDMA wireless communication system - Google Patents

Description

The present invention relates to a wireless relay station in a TDMA (time division multiple access) wireless communication system, and in particular to a time position of a time slot in which a slave station is assigned to itself. The present invention relates to a transmission timing control technique for relay-transmitting a short burst signal to be transmitted to a central station in order to determine the

(Prior Art) A TDMA wireless communication system includes, for example, as shown in FIG. 4, a central station 1, a plurality of slave stations (2 ₁ to 2 ₃ ) directly wirelessly connected to the central station 1, It is composed of one or a large number of wireless relay stations (hereinafter, simply “relay stations”) 3 and a plurality of slave stations 2 ₄ wirelessly connected to the central station 1 via the relay stations 3. As is well known, the wireless line has a plurality of time slots (TSs) as illustrated in FIG.
_{1 ~TS N)} becomes a repetition of the frame consisting of, each slave station wirelessly transmits a burst signal in the time position of the time slot assigned to its own station.

By the way, since the time position of each time slot is based on the time axis in the central station 1, each slave station considers the propagation time so that the central station 1 receives the burst signal in order to receive it at the correct time. However, the propagation time between the slave station and the central station 1 is usually different for each slave station.
Therefore, it is necessary to set the transmission timing of the burst signal for each slave station.

Since the TDMA wireless communication system is constructed around the central station 1, the transmission timing control of burst signals is also performed by the central station 1.
The transmission timing control in the related art is performed by the slave stations 2 ₁ to 2 ₃ directly wirelessly connected to the central station 1 and the slave stations 2 ₄ wirelessly connected to each other via the relay station 3. The control method was slightly different. This is because the relay station 3 was later joined to expand the service zone.

FIGS. 3B and 3C are explanatory diagrams of the transmission timing control for the slave stations 2 ₁ to 2 ₃ . First, the central station 1 sends control information instructing the transmission timing control to the time slot T.
Transmitted in S _K to the relevant slave station. Then, since Gaitoko station transmits a short burst signal SBS of shorter duration than the time slot length at an appropriate time position in the designated time slot TS _K, as shown in FIG. 3 (b) ,
Short burst signal SBS is received at time t _y addressed delayed time positions from the start position of the specified time slot TS _K in the central station 1. Therefore, the central station 1 delays the delay time t _y.
Is measured and the time difference information is transmitted to the corresponding slave station at an arbitrary time slot. This allows the slave station to accurately determine the burst signal transmission timing to the central station 1. The short burst signal is constructed as shown in FIG. 3 (c), and the identification number of the corresponding slave station is set in the "identification number" area. The central station 1 thereby identifies the partner slave station which transmits the time difference information. The transmission timing control method described above is described in detail in JP-A-58-99044.

On the other hand, the slave station 2 ₄ via the relay station 3 is performed as follows. First, the central station 1 transmits to the relay station 3 the control information for Gaitoko station in the time slot TS _K. Then, the relay station 3 as well as directly relayed to the downstream signals of the time slot TS _K, identifies the time slot TS _K detects the control information. Then, since the corresponding slave station transmits a short burst signal at the designated time slot TS _K , the relay station 3 causes the relay station 3 to transmit the time slot TS _K.
The delay time from the start position of _K to the reception position of the short burst signal is measured, and the time difference information is used as the time slot TS _K.
Send to Central Office 1. In response to this, the central station 1 transmits the time difference information to the corresponding slave station via the relay station 3 in an arbitrary time slot as described above.

(Problems to be Solved by the Invention) However, in the TDMA wireless communication system including the relay station, as described above, the central station controls the slave station directly wirelessly connected and the slave station via the relay station which are slightly different from each other. It is supposed to be done. Therefore, conventionally, the central station requires two systems of the short burst signal receiving system and the time difference information receiving system, which causes a problem that the device configuration and the control mode are complicated.

The present invention has been made in view of such a problem, and an object thereof is to provide a wireless relay station capable of simplifying a device configuration and a control mode of a central station.

(Means for Solving the Problems) In order to achieve the above object, the wireless relay station in the TDMA wireless communication system of the present invention has the following configuration.

That is, the wireless relay station in the TDMA wireless communication system of the present invention includes at least a central station, one or a plurality of wireless relay stations, and a plurality of slave stations wirelessly connected to the central station via the wireless relay stations. (Time-division multiple access) A wireless relay station in a wireless communication system; this wireless relay station receives control information transmitted by a central station in a predetermined time slot, and transmits the control information to a slave station in the time slot. Means for relay-transmitting and setting a reception time slot for receiving a short burst signal relating to the slave station transmission and a transmission time slot for transmitting the short burst signal to the central station based on the control information; The slave station receiving the control signal receives the short burst signal having a time width shorter than the time slot length transmitted in the designated time slot. Te means for detecting a receiving position in the receive timeslot of the short burst signals;
Means for transmitting the received short burst signal to the central office at a time position equal to the detected reception position of the transmission time slot;

(Operation) Next, the operation of the wireless relay station in the TDMA wireless communication system of the present invention configured as described above will be described. The wireless relay station of the present invention relays the control information transmitted from the central station in a predetermined time slot to the slave station in the time slot, and sets the reception time slot and the transmission time slot based on the control information. . Then, the slave station receives the short burst signal transmitted in the designated time slot, detects the reception position of the short burst signal in the reception time slot, and outputs the received short burst signal in the transmission time slot. It transmits to the central office at a time position equal to the detected reception position.

Here, if the time adjustment between the central station and the wireless relay station is correct, the delay time of the short burst signal received by the central station from the wireless relay station is the same as the delay time of the short burst signal received by the wireless relay station from the slave station. It will be exactly the same. Thus, if the central station transmits the time difference information, which is the delay time of the received short burst signal, to the relevant slave station via the wireless relay station, the relevant slave station can reliably perform transmission timing control. .

In short, the central station can control the transmission timing of the slave station via the wireless relay station by the same procedure as that of the slave station without the wireless relay station. I wish I had it. Also, it means that a single control procedure is sufficient.

(Example) Hereinafter, the Example of this invention is described with reference to drawings.

FIG. 1 shows the configuration of a wireless relay station according to an embodiment of the present invention. In Figure 1, an antenna 11, receiver 12, demodulator 13, the route of the relay circuit 14, modulator 15, transmitter 16, antenna 17 is a downlink relay route to the central station 1 slave station _{2 4.} The antenna 27, receiver 26, demodulator 25, a relay circuit 24, a modulator 23, the root of the transmitter 22, antenna 21 is an uplink relay route from slave station _{2 4} to the central station 1.

The output of the demodulator 13 on the downlink relay route is also led to the control signal detection circuit 101. Central station 1, as shown in example FIG. 2 (b), and send a control signal for transmission timing control in the time slot TS _K (This transmission is performed periodically), it is downlink relay route It is sent to the slave stations 2 ₄ through. Figure 2 (C) (F)
Indicates that. _tr is the internal delay time. In this relay operation, the control signal detection circuit 101 that receives the output of the demodulator 13 detects the control signal and detects the time slot T.
S _K knows that the reception time slot and the short burst signal for receiving a short burst signals in accordance with the child station transmits a transmission time slot for transmission to the central station, it short burst signal detection circuit 102, It outputs to the delay time detection circuit 103 and the timing adjustment circuit 104, respectively.

Control signal time slot TS _K according to the relay station 3 transmits, as shown in FIG. 2 (g), is received in the slave station 2 ₄ takes the propagation time t _d. Then, as shown in FIG. 2 (h), the slave station 2 ₄ short bursts when the starting position was the time t ₀ has elapsed time slot TS _K in a A in time slot TS _K after a predetermined time t _X elapsed Send the signal SBS. This short burst signal SBS is received by the relay station 3 at the time position shown in FIG.

In the relay station 3, this short burst signal SBS is transmitted to the antenna 2
7. The signal is output from the demodulator 25 via the receiver 26 to the relay circuit 24 and the short burst detection circuit 102, respectively. The relay circuit 24 is for relaying general burst signals (burst signals other than short burst signals), and is not designed to relay short burst signals. Short burst detection circuit 1
In 02, upon receipt of the command from the control signal detection circuit 101 sets the reception time slot TS _K from the start position of the time slot TS _K which receives the control signal from the central station 1 to the time t _e spaced time position Short burst signal SBS
Waiting for reception of the reception time slot TS _K
When the short burst signal SBS is detected by, the detection signal is detected by the delay time detection circuit 103 and the short burst signal transmission circuit 10.
Output to 5 and 5, respectively.

Then, the delay time detection circuit 103 detects the reception position in the receiving time slot TS _K measures the delay time t _y, and outputs the time difference signal to the timing adjustment circuit 104. The timing adjustment circuit 104 is the control signal detection circuit 1
In response to the command from 01, the transmission time slot TS _K
Set, determine the delay position of the time t _y in the transmission time slot TS _K and sends the position of the short burst signals SBS,
It is output to the short burst signal transmission circuit 105. As a result, as shown in FIG. 2D, the short burst signal SBS is located at the delay time t _Y within the transmission time slot TS _K.
Is set and is transmitted to the central office 1 via the modulator 23, the transmitter 22 and the antenna 21. In addition,
"Identification number" area of the short burst signals transmitted are set identification number of the slave station 2 _4. There is little need to include the relay station 3 number.

Thus to the central station 1, as shown in FIG. 2 (b), it receives a short burst signal SBS from the relay station 3 at the reception time slot TS _K that is set, the delay time t _y To detect. At this time, if the time adjustment between the central station 1 and the relay station 3 is properly performed, the delay time of the short burst signal SBS received from the relay station at the central station 1 is determined by the relay station 3 as the slave station 2 The delay time of the short burst signal SBS received from No. ₄ is exactly the same. Therefore, if the central station 1 sends the time difference information signal, which is the delay time t _y of the short burst signal SBS, to the slave station 2 ₄ via the relay station 3 in an arbitrary time slot, the slave station 2 ₄ Can adjust the time t _X to be sent to the relay station 3 by the time difference information signal from the central station 1.

(Effects of the Invention) As described above, according to the wireless relay station in the TDMA wireless communication system of the present invention, the received short burst signal is transmitted to the central station while holding its reception delay time. The central station can control the transmission timing of the slave station via the wireless relay station by the same procedure as that of the slave station without the wireless relay station. As a result, the central station only needs to have a short burst reception system as the receiving system and has a single control procedure, which has the effect of simplifying the device configuration and control mode.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of a wireless relay station according to an embodiment of the present invention, FIG. 2 is a signal time relationship diagram between a central station, a relay station, and slave stations, and FIG. 3 is a transmission timing explanatory diagram of the slave station. , FIG. 4 is an overall configuration diagram of a TDMA wireless communication system. 1 ... Central station, 2 ₁ to 2 ₄ ... Slave station, 3 ... Relay station, 1
1 ... Antenna, 12 ... Receiver, 13 ... Demodulator, 1
4 ... Relay circuit, 15 ... Modulator, 16 ... Transmitter, 1
7 ... antenna, 21 ... antenna, 22 ... transmitter,
23 ... Modulator, 24 ... Relay circuit, 25 ... Demodulator,
26 ... Receiver, 27 ... Antenna, 101 ... Control signal detection circuit, 102 ... Short burst signal detection circuit, 10
3 ... Delay time detection circuit, 104 ... Timing adjustment circuit, 105 ... Short burst signal transmission circuit.

Claims (1)

[Claims] 1. A TDMA (time division multiple access) wireless communication system comprising at least a central station, one or a plurality of wireless relay stations, and a plurality of slave stations wirelessly connected to the central station via the wireless relay stations. The wireless relay station receives the control information transmitted by the central station in a predetermined time slot, relays the control information to the slave station in the time slot, and based on the control information. Means for setting a reception time slot for receiving a short burst signal relating to the slave station transmission and a transmission time slot for transmitting the short burst signal to the central station; Receiving the short burst signal having a time width shorter than the time slot length to be transmitted in the specified time slot, and receiving the short burst signal in the reception time slot. Means for detecting a kick receiving position;
Means for transmitting the received short burst signal to a central office at a time position equal to the detected reception position of the transmission time slot;
A wireless relay station in a DMA wireless communication system.