JPS58145249A - Time division multiplex connecting system - Google Patents

Abstract

PURPOSE:To use various transmission and reception equipment having different performance in common and to improve the flexibility and versatility of a comminication system, by setting the transmission speed of synchronizing control burst and data burst constituting the frames into plural values. CONSTITUTION:Signals having different clock speeds are mixed in one frame F. The clock frequency has the relation of fp1>fp2>fp3, the fp1 is transmitted and received between slave stations 10 and 13, the fp2 is among 10, 11, 13, 14, and the fp3 is received and transmitted among slave stations 10-15. The clock frequency of a synchronizing burst group S is received at each slave station in common by setting it to the fp3.

Description

DETAILED DESCRIPTION OF THE INVENTION [Description of the Field to which the Invention Pertains] The present invention relates to a wireless time division communication system suitable for satellite communication systems. In particular, it relates to a time division multiplex (DMM) system that enables communication between a plurality of transmitting and receiving stations with different performances.

[Description of conventional technology]

FIG. 1 is a signal configuration diagram of a conventional time division multiplex II concatenation system. FIG. 1(a) shows the structure of 141 frames r,
One frame F is composed of a synchronous control burst group and data burst groups (D, to Dn) of various time lengths. Figures 1~) are partially enlarged views of the G41j guard time, 8A is the synchronization information signal, C0 is the control signal, and op#'
This is the i-suke signal. It is also a Dii data signal.

Transmission/reception signal #i synchronization - burst 8 synchronization information signal By
1, carrier synchronization, clock synchronization, and frame period are performed, and the data signal is output according to the color code CtK.
Perform burst allocation of Dn. Now set up the sand communication system and communicate with K.

FIG. 2 is a diagram showing a communication type Il of a conventional hour-minute-1 multiple access system using a satellite as a relay station. l is a relay station (lIJ star) 2.3 is a slave station (earth station) f: indicates.

In the conventional method, as shown in Fig. 1, each burst has the same transmission speed of 1 ft; fp, so each slave station has the same performance that can transmit and receive signals at the same transmission speed, or It is necessary to provide equipment with performance below -F. Even if there is a station that requires less transmission capacity, it has the drawback of requiring equipment that matches the performance of a large scale network, making it uneconomical.

[Purpose of the invention]

An object of the present invention is to provide a system in which even stations equipped with economical equipment whose performance differs depending on the transmission capacity can be connected to one system using a time division multiplex eleven concatenation system.

[Key points of the invention]

The present invention sets the transmission speeds of synchronization control bursts and data bursts constituting a frame to a plurality of different values, so that the transmitting station transmits at a receivable transmission speed that matches the performance of the other receiving station. The main feature of this system is that each transverse transmission/reception facility is used in a mixed manner to communicate with each other.

[Explanation based on examples]

FIG. 5 is a signal configuration diagram of the system according to the embodiment of the present invention.

The interval between the vertical broken lines shown in FIG. 5(a) K represents the interval between communication clocks, and indicates that in the method of the present invention, signals of different clock speeds coexist in frame 1 of 1i1i1. Each reference numeral in FIG. 5 is the same as that of the conventional system explained in FIG.

Figure 4 is a diagram showing a communication type m according to an embodiment of the present invention.

In this example the clock frequencies are fpl, fPl and fp
Three types of i are set, and their values are fp, 〉fp2〉fP
For fp, which has the highest clock frequency,
Only slave stations 10 and 13 can transmit and receive, and other stations do not have the equipment to support this clock frequency.

Regarding clock frequency fp2, slave stations to, ti and 13.14 can transmit and receive. clock frequency fpi
can be transmitted and received by all slave stations 10 to 15.

In such a configuration, for example, slave stations 12 and 15 can only transmit and receive fpSK, which has a low frequency.
□All you need to do is have the equipment to do so. The antenna may have a small diameter, and the communication circuit may be an economical equipment that can achieve a predetermined error rate at low speed tK.

If the relay station equipment of satellite 1 is a device that amplifies and transmits the received signal, the highest clock frequency fp,
If it has the performance to correspond to the lower frequency fp2% fp, K, it is possible to perform all relay transmissions with sufficient margin.

When the equipment of the relay station is a regenerative relay system, the clock frequencies 'p1, f p2, and t p are preferably set to be integral multiples of each other.

If the clock frequency of the synchronous control burst group 8 is the lowest clock frequency fpi, each slave station can receive it in common. It is also possible to transmit the periodic control signal separately at each clock frequency fp, , fp, , fps.

In the above example, the difference in transmission speed is due to the difference in clock frequency, but in addition, even if the clock frequency is the same or different, it may be due to the modulation level of multi-level modulation, or the difference in multi-phase modulation. The present invention can be practiced even when the number of modulation phases of modulation is different.

[Explanation of effects]

As explained above, since bursts in the frame structure of the time division multiple access system are composed of various transmission speeds,
Each slave station only needs to be equipped with equipment of a size or performance that corresponds to the required communication capacity, and the slave station equipment can be shielded. The present invention allows slave stations or earth stations of various communication capacities to be interconnected, which has the advantage of increasing the flexibility and diversity of the communication system.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an example of a frame structure of a conventional time division multiple access system. FIG. 2 is a diagram showing a conventional communication type AT using time division multiple access. FIG. S is a frame configuration diagram of an embodiment of the present invention. FIG. 4 is a diagram showing a communication type mt according to an embodiment of the present invention. Patent applicant: Nippon Telegraph and Telephone Public Corporation, patent attorney: Naotaka Ide

Claims (1)

[Claims] (1) A wireless transmission path is configured between a plurality of slave stations and one relay station. A time division multiple access method in which each slave station transmits all burst signals at the time allocated to that station that arrives every frame period, and the relay station relays this burst signal to communicate between the multiple slave stations. A time division multiple access system characterized in that the clock speed in the burst signal has a plurality of different transmission speeds depending on the transmitting station and receiving station of the burst signal.