JPH1117603A - Communication system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To select an optimum base station, even in the case that a radio equipment reception input voltage level fluctuates by transmitting the radio equipment reception input voltage level of a lower-order base station unit to a higher-order base station, comparing it with the radio equipment reception input voltage level of the present station in the higher-order base station and performing output. SOLUTION: The radio equipment reception input voltage level on a lower- order station side is inputted from a reception line via an equalizer to a modem 8 for a lower-order station radio equipment reception input voltage level and inputted to a control part 6 in a digital signal form. Meanwhile, reception input voltage level signals and call termination signals from the radio equipment 1 of the present station are directly inputted to the control part 6. The control part 6 compares and judges the radio equipment reception input voltage level of the lower-order base station and the radio equipment reception input voltage level of the present station and outputs the radio equipment reception input voltage level signals of the present station and the lower-order base station along with the judged result. By successively performing the control operations inside the base station, an optimum base station is selected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for selecting a plurality of base stations in a communication system such as a train radio system.

[0002]

2. Description of the Related Art FIG. 3 shows a configuration example of a conventional base station apparatus of a train radio system in which an approach line is composed of two transmission lines and two reception lines. In FIG. 3, a transmission line from an upper station passes through an equalizer and is divided into a radio modulation input direction and a lower base station apparatus direction. A transmission start signal and a base station control signal are superimposed on the transmission signal from the upper station (central unit) in addition to the radio modulation, and are detected by the transmission start signal detecting unit 10 and the base station control signal detecting unit 13, respectively. Is transmitted to the control unit 12. The radio modulation signal is
After division, the signal is input to the wireless device 1 via the LPF and the buffer amplifier. The demodulated output of the wireless device 1 is supplied to the receiving line switching circuit 11 via the buffer amplifier.

The demodulated signal from the lower station passes through an equalizer and is supplied to a receiving line switch circuit 11. The receiving line switching circuit 11 is controlled by a switching signal from the control unit 12. This switching signal is controlled by an incoming signal input from the wireless device 1 to the control unit 12. That is, if the own station is receiving a call, the receiving line switch circuit 11 disconnects the lower station and connects the wireless device 1, and if not, disconnects the wireless device 1 and connects the lower station. ,
The signal is transmitted to the upper station via the buffer amplifier.

[0004]

The above-mentioned prior art includes the following:
Since the switching control of the receiving line is controlled by the radio reception signal of the upper base station, there is a problem that when the radio reception input voltage level from the running train fluctuates, the optimum base station cannot be selected.

[0005]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention transmits a radio receiver input voltage level of a lower-level base station apparatus to an upper-level base station, and the upper-level base station transmits the radio signal of the own station. Compared with the reception input voltage level, the one having the higher reception input voltage level is output to the central control device side. FIG. 1 shows a configuration of a train radio system according to an embodiment of the present invention. The central station comprises an operation panel and a central control unit 100, and is connected to the base station device via a transmission line and a reception line. Each base station device 101-1 to 101-n
(N is an integer of 2 or more) includes a radio 1, a control unit 2, an S / N determination unit 3, a transmission line unit, and a reception line unit included in the control unit 2. In this train radio system, the S / N determination unit 3 includes a reception input voltage level signal from the lower base station and a reception input voltage level signal (RS
Si) is given, the input voltage levels of these two signals are compared and determined, and the receiving line switch circuit 4 and the wireless device demodulation signal switch circuit 5 of the own station are controlled based on the result of the determination.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIG. In the figure, 1 is a radio, 4 is a reception line switch circuit, 5 is a radio demodulation signal switch circuit, 6 is a control unit, 7 is a modem, 8 is a modem for a lower station radio reception input voltage level, and 9 is a modem output. The signal switch 10 is a radio transmission start signal detection circuit. Next, the operation of this embodiment will be described. First, the lower station side radio receiver input voltage level is input to the lower station radio receiver input voltage level modem 8 from the receiving line via an equalizer, and is input to the controller 6 in the form of a digital signal. On the other hand, a reception input voltage level signal (RSSI signal) and an incoming signal (squelch level signal) from the wireless device 1 of the own station are directly input to the control unit 6. The control unit 6 compares and determines the radio reception input voltage level of the lower base station with the radio reception input level of the own station, and, together with the judgment result, the radio reception input voltage level signals of the own station and the lower base station. , Via the modem 7 and the modem output signal switch 9.

[0007] Here, when the radio receiver input voltage level of the base station is high, the radio demodulation signal switch circuit 5 is connected and the reception line switch circuit 4 is closed. On the other hand, when the radio receiver input voltage level of the lower base station is high, the radio demodulation signal switch circuit 5 is closed and the reception line switch circuit 4 is connected. When the level is the same for both the own station and the lower base station, the connection to the lower base station is prioritized. The above control operation in the base station is performed by the lowest base station 1 shown in FIG.
By performing the operations from 01-n to the highest base station 101-1 sequentially, an optimum base station for performing communication with a train (mobile station) can be selected from a plurality of base stations. The modem 7 is also used for information transmission of a base station control signal and a base station monitoring signal from the central control unit. The lower station radio receiver input voltage level modem 8 is also used for transmitting the supervisory signal of the lower station. The transmission of the monitoring control signal using such a modem is performed during a non-communication.

In the above embodiment, the case where the communication system is a train radio system has been described. However, the present invention is not limited to this, and a central station and a plurality of base stations are arranged, and a plurality of mobile stations are provided. The present invention can be applied to a general communication system that performs communication via one of the base stations.

[0009]

As described above, according to the present invention,
In a communication system having a plurality of base stations, it is possible to always and automatically select an optimum base station for a call. In particular, if the present invention is applied to a train radio system,
The base station can be automatically tracked in accordance with the running train, and an excellent effect that the duration of the call becomes longer can be obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a base station device according to one embodiment of the present invention.

FIG. 3 is a block diagram showing an example of a conventional base station device.

[Explanation of symbols]

1: Radio, 2, 6, 12:
Control section, 3: S / N determination section, 4, 1
1: Receiving line switch circuit, 5: Radio demodulation signal switch circuit, 7, 8: Modem, 9: Modem output signal switch circuit, 10: Radio transmission start signal detection unit, 1
3: Base station control signal detection unit.

Claims (1)

[Claims] 1. A communication including a central control device and a plurality of base station devices, wherein an approach line including a transmission line and a reception line is connected between the central control device and the base station devices and between each base station device. In the system, each of the base station devices includes a radio and a control unit, and in the control unit, reception input voltage level data from the radio of the own station and reception input voltage of the lower base station transmitted from the lower base station Comparing means for comparing the level data with the level data, transmitting means for transmitting the comparison result to the upper station via the receiving line, and a switch for selecting either the demodulated output of the own station radio or the receiving line from the lower base station And a S / N determination means for controlling switching of the switch.