JPH05175893A - Radio communication system - Google Patents

Abstract

PURPOSE:To prevent speech quality from being degraded and to surely execute command speaking and urgency speech by designating base station transmission to one station after a simultaneous call while selecting a receiving line by S/N comparison and simultaneous selecting a transmitting line as well. CONSTITUTION:This system is composed of one command point 1, plural base stations 8-10 and plural mobile stations 11 and 12. When the positions of the mobile stations 11 and 12 are discriminated by the command point 1, one-base station selecting transmission is executed, when the positions are not discriminated, simultaneous transmission is executed, one moving station is called by sounds and concerning the received sounds of the base stations 8-10, the sound of only one base station is selected by an S/N comparing signal at the command point 1. In this case, the transmission is executed while automatically selecting only the base station having the highest S/N of the received audio signal at the command point 1 in the case of simultaneous transmission. Since the ratio of speech with the base stations 8-10 for the mobile stations 11 and 12 is 1:1, the speech quality is not degraded and since the transmitting line is also switched simultaneously to the receiving lines of the base stations 8-10 even when the mobile stations 11 and 12 move to the adjacent base zone, automatic pursue is enabled.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wireless communication system for reducing deterioration of speech quality due to interference distortion in mobile communication.

[0002]

2. Description of the Related Art As a conventional technique, as shown in FIG. 2, in a communication system including a command desk 1, a controller 2, a plurality of base stations 8-10, and a plurality of mobile stations 11-12, a command desk is used. When calling the mobile station 11 from 1, when the position of the mobile station is known, when the base station 8 is designated from the command console 1, the transmission switch 4 of the control device 2 operates and the transmission line to the base station 8 is activated. 8a is connected and the base station 8 transmits only one station.
On the other hand, the voice signal from the mobile station 11 is received by the base station 8 or the base station 9 and sent to the control device 2 via the receiving lines 8b and 9b. Further, the S / N comparison signal proportional to the received electric field strength is sent to the S / N comparison circuit 6 of the control device 2 through the lines 8c, 9c. The S / N comparison circuit 6 detects the base station having the highest S / N, the reception switcher 7 selects the reception line of the base station based on its output, the amplifier 5 amplifies it, and outputs it to the command console 1. With this method, the base station and mobile station are 1: 1
Since the distortion due to interference disappears, a clear call can be secured.

[0003]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
There is no problem when the mobile station is in the zone of a certain base station, but when the mobile station moves to another base station zone, it is necessary to manually switch the transmitting base station. Since the mobile station is called by calling, there is a disadvantage that interference distortion occurs in the received signal of the mobile station in the equal electric field section between the base stations until the end of the call. The present invention solves these drawbacks, and when a mobile station moves from one base station zone to another base station zone, the transmission base station is automatically switched and simultaneous paging is performed. The purpose is to enable transmission, reception by one base station, and reliable execution of command calls and emergency calls.

[0004]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention selects a receiving line by S / N comparison and a transmitting line at the same time, so that a base station transmission after a simultaneous call can be reduced. It is a station.

[0005]

As a result, in the mobile station, the communication with the base station becomes 1: 1 so that the deterioration of the communication quality is eliminated, and even if the mobile station moves to the adjacent base station zone, the reception line of the base station and the reception line of the base station are simultaneously generated. Since the transmission line is also switched, automatic tracking is possible.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to FIG. 1 is a command desk, 2 is a control device, 3 is a transmission voice amplifier,
4 is a transmission line switch, 5 is a reception voice amplifier, 7 is a reception line switch, 8 to 10 are base stations, 8a to 10a are voice signal transmission lines from the command console to the base station, and 8b to 10b are base stations. Voice signal reception lines, 8c to 10c are S / N comparison signal reception lines from the base station, 11 and 12 are mobile stations, 13 is an S / N comparison circuit, and 14 is a transmission line control circuit. There is no problem even if the number of base stations and mobile stations is increased from the number shown in FIG.

When the mobile station 11 is moving in the direction of the base station 9 with respect to the zone of the base station 8, the base station 8 is designated on the command desk and a call is made via the line 8a. When the mobile station responds, the voice received by the base stations 8 and 9 is sent to the receiving line switch 7 of the control device 2 via the lines 8b and 9b. At the same time, the S / N comparison signal is also sent to the S / N comparison circuit 13 via the lines 8c and 9c, but since the base station 8 is stronger, the reception line 8b of the base station 8 is connected and passes through the reception voice amplifier 5. It is output to the command desk 1. In addition, the base station 8 from the S / N comparison circuit
Selection signal is sent to the transmission line control circuit 14. At this time, the transmission line is fixed at the base station 8 because the designation on the command console and the selection signal match.

When the mobile station enters the zone of the base station 9, S / N
Since the comparison signal is stronger at the base station 9, the S / N comparison circuit 13 makes a decision and the reception line switch is switched to the line 9b of the base station 9. At the same time, the transmission line control circuit 14 is instructed to select the line 9a of the base station 9, and the transmission line switching unit 4 switches to the base station 9.

Next, when calling all at once, all the base stations are transmitted. However, when the mobile station responds, the S / N comparison signal of the base station that received the radio wave most strongly is strong, and therefore the reception of that base station is received. A line is selected, and at the same time, a transmission line switching signal is output to the transmission line control circuit 14, the transmission line is also switched, and the base station is selected.

According to this method, the speech quality of the mobile stations in the equal electric field section between the base stations at the time of simultaneous paging is temporarily deteriorated due to interference, but when the mobile station responds,
Since the base station with the best S / N is selected and only one base station is transmitting, there is no interference distortion and reliable communication is possible, and automatic tracking of the movement of the mobile station is also possible.

[0011]

EFFECTS OF THE INVENTION According to the present invention, simultaneous transmission of a plurality of base stations is performed only at 1 o'clock of the simultaneous call, and the other one is transmitted by one base station and received by one base station. This will ensure safer operation and faster maintenance.

[Brief description of drawings]

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

FIG. 2 is a block diagram showing a conventional method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Command desk 2 Control device 3 Transmission voice amplifier 4 Transmission line switching device 5 Reception voice amplifier 6,13 S / N comparison circuit 7 Reception line switching device 8-10 Base station 11-12 Mobile station 14 Transmission line control circuit

Claims (1)

[Claims] 1. A single command station, a plurality of base stations, and a plurality of mobile stations. When the position of the mobile station is known from the command station, one base station is selected for transmission, and when the position is unknown, simultaneous transmission is performed. In a mobile communication system in which transmission is performed, one mobile station is called by voice, and the received voice of the base station is selected by the S / N comparison signal at the command station. A wireless communication system characterized by automatically selecting and transmitting only the base station with the highest S / N of the voice signal.