JPH0228932B2 - JIBUNKATSUTAGENSETSUZOKUTSUSHINHOSHIKINOJUKYOKUSEIGYOSOCHI - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention is directed to time division multiple access (hereinafter referred to as "TDMA").
That's what it means. ) Relates to a slave station control device for a slave station in a satellite communication system. In particular, the present invention relates to an initial connection control method performed prior to when a reference station performs regular control over a slave station.

[Conventional technology]

In the TDMA satellite communication system, considering the periodic division of time on the satellite, this TDMA frame is time-divided and assigned to each earth station, and each earth station transmits its own signal within the allocated time. Send. That is, each transmitted signal is a burst with a period equal to a TDMA frame. Therefore, this burst synchronous control is an important basic technology in this system.

By the way, in the initial state before the burst is emitted, the exact timing at which the burst should be emitted is unknown, and initial connection control is required to know this.

In the TDMA satellite communication system, when a reference station starts controlling a slave station, initial connection control is performed prior to regular control. That is, the reference station performs initial connection control for the slave station, and when the burst from the slave station is normally received, the initial connection control is ended and normal control is started.

FIG. 3 is a flowchart showing the algorithm of the initial connection control method performed by the reference station on the slave stations.

When the reference station starts controlling the slave station,
Initial connection control is performed prior to regular control. For example, when a base station starts controlling a slave station, it first sends initial connection control information to the slave station, and the base station opens a wide window at the initial connection control position of the slave station so that the slave station can burst. Wait for it to be received. When a slave station sends a burst to its initial connection control position, the reference station measures the burst position, creates control information from the difference between this measured position and the normal position, and sends it to control the burst of the slave station. Place it in the correct position.

The reference station then moves the window to the slave's regular position, and once the slave's burst is received there,
Ends initial connection control and shifts to regular control.

That is, the initial connection control performed when the reference station starts controlling the slave station substantially starts when the burst of the slave station is received in the window of the initial connection control position, and the controlled burst of the slave station is received within the window of the normal position. Once the connection is received again, the initial connection control can be terminated and the control can be transferred to regular control.

[Problem that the invention seeks to solve]

However, in such a conventional initial connection control method, when there are two or more reference stations, those reference stations must simultaneously start initial connection control for the slave station. However, it is impossible to start initial connection control at the same time, and there is generally a time difference. Therefore, the burst of the slave station has already been placed at the normal position according to the control information of the reference station that started the initial connection control first, and this burst is delayed.
If there is a difference between the burst position of the slave station at its normal position and the initial connection control position, the reference station participating in the TDMA satellite communication system will control the burst position at the normal position of the slave station once it enters initial connection control. The reference station could not recognize it and therefore could not terminate this control.

In other words, when considering the burst arrangement shown in Figure 4, there is a difference between the normal position of slave station A and the initial connection control position, and the second reference station that starts initial connection control later , even if the initial connection control position is waiting for the burst of slave station A, the burst of slave station has already been placed at the correct position by the first reference station, and the burst of slave station A cannot be recognized by the second reference station. I couldn't do it.

Therefore, even though the slave station's burst is placed at the regular position, the base station cannot shift to regular control, and the base station that started initial connection control first performs regular control over the slave station. There was a problem in that the control information for the slave station would not match, as the reference station that joined later would send out initial connection control information.

Further, even one reference station generally has a redundant system, and the reference station device is often composed of two or more, and the same thing as above can be said in this case as well.

The present invention has been made by focusing on such conventional problems, and the reference station or reference station device that starts initial connection control later has to follow the reference station or reference station device that is performing initial connection control first. It is an object of the present invention to provide a slave station control device for a time division multiple access communication system that can normally shift to regular control.

[Means for solving problems]

According to the present invention, when a reference station starts controlling a slave station, a window is opened at the initial connection control position of the slave station, and if a burst transmitted by the slave station is not confirmed, then a window is opened at the regular position of the slave station, The present invention is characterized in that it includes a means for confirming the burst transmitted by the slave station.

That is, the system includes two or more reference stations and a plurality of slave stations that are independently controlled by the two or more base stations, and the base station includes a control means that performs initial connection control on the slave stations prior to regular timing control. The control means includes means for opening a window at the initial connection control position of each slave station for reception of the burst before the reference station starts controlling the slave station, and a means for opening a window for reception of the burst at the initial connection control position of each slave station, and a means for opening a window for reception of the burst of the slave station in the initial connection control position of each slave station before the reference station starts controlling the slave station. in a slave station control device for a time division multiple access communication system, the control means includes means for opening a window at a normal timing control position when a burst from the slave station is not received within a predetermined time period; The present invention is characterized in that it includes means for directly shifting to regular timing control without performing initial connection control when a reception burst is confirmed at a regular timing position of the slave station.

[Effect]

In the present invention, when the burst has already been controlled to the normal position by the reference station or reference station device that started the initial connection control of the slave station first, the reference station or the reference station device that starts the initial connection control later starts the initial connection control. Since the control can be shifted to normal control without any delay, the control information that different reference stations or reference station devices perform on the slave station will not be inconsistent.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram illustrating an embodiment of the present invention. In FIG. 1, window control information 11 is output from the slave control circuit 1 to the window generation circuit 2, window information 21 is output from the window generation circuit 2 to the burst signal detection circuit 3,
Burst signal detection information 31 is output from the burst signal detection circuit 3 to the slave station control circuit 1. Furthermore, initial connection control information or regular control information 12 is output from the slave control circuit 1.

The slave station control circuit 1 is composed of a microprocessor and has a built-in timer. The microprocessor performs a series of controls to execute the algorithm, such as instructing the window for receiving bursts from the slave station, checking the burst reception status of the slave station, ending initial connection control, and transitioning to regular timing control. It has been realized.

The window generation circuit 2 generates a window (initial connection control position or regular timing control position) instructed by the slave station control circuit 1. The initial connection control position window has a wide width, and the regular timing control position window has a defined width.

The burst signal detection circuit 3 is a circuit that detects whether a burst from a window slave station generated by the window generation circuit 2 is being received.

FIG. 2 is a flowchart illustrating the operation of an apparatus according to an embodiment of the present invention.

In the slave station control device of the present invention, when starting initial connection control of a slave station with a reference station, it sends initial connection control information to the slave station, starts a timer, and opens a wide window at the initial connection control position. Wait for the slave's burst to be received. If the slave's burst is not received until the timer reaches a predetermined value, it moves its window to the regular timing control position while transmitting initial connection control information.

If the slave's burst cannot be received even at the normal timing control position, the window is returned to the initial connection control position and the timer is reset and started again. The reference station continues this operation repeatedly until the slave station's burst is received. Also,
If a slave burst is received, the timer is reset.

If the slave burst is received at the initial connection control position, it will enter the initial connection control according to the conventional algorithm, and if it is received at the regular timing control position, it will directly enter the regular connection control without going through the initial connection control. Shift to timing control.

In a TDMA satellite communication system, a burst from a slave station is placed at its normal position or initial connection control position as long as the slave station is transmitting bursts normally. By adopting this algorithm, the reference station is always located at this position. It is possible to receive the burst from the slave station and shift to normal regular timing control.

〔Effect of the invention〕

The present invention provides control information for a slave station of a reference station that joins a TDMA satellite communication system later or a reference station device that enters an operational state later than that of a reference station that already exists in the TDMA satellite communication system or a reference station device that is already in operation. It is guaranteed that the control information for the slave stations is the same.

Therefore, the initial connection control and regular timing control performed by the reference station on the slave station can be performed without error regardless of when the control is started.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing one embodiment of the present invention. FIG. 2 is a flowchart explaining the operation of the apparatus according to the embodiment of the present invention. FIG. 3 is a flowchart showing a conventional control algorithm for slave stations. Fourth
The figure shows an example of burst placement on a frame. 1...Slave station control circuit, 2...Window generation circuit, 3
...Burst signal detection circuit, 11...Window control information, 12...Initial connection control information or regular control information, 21...Window information, 31...Burst signal detection information.

Claims (1)

[Scope of Claims] 1. Comprising two or more reference stations and a plurality of slave stations that are independently controlled by the two or more base stations, the reference station has a predetermined timing control function for the slave stations prior to regular timing control. control means for performing initial connection control; the control means, before the reference station starts controlling the slave stations, means for opening a window at the initial connection control position of each slave station for receiving the burst; and means for confirming that the burst from the slave station has been received in the window; , means for opening a window at the regular timing control position, and means for directly switching to regular timing control without performing initial connection control when a reception burst is confirmed at the regular timing position of the slave station. A slave station control device for a time division multiple access communication system, characterized by: