JPS63292731A - Radio relay system in weak electric field - Google Patents

Abstract

PURPOSE:To improve S/N, to uniformize a reception level and to prevent the interference between signals by using a booster constituted integratingly by a transmission/reception exclusive antenna and an amplifier as a repeater. CONSTITUTION:Boosters 11-13 comprising reception exclusive amplifier are provided with antennas 11A-13A of equal length and boosters 21-23 comprising transmission exclusive amplifier are provided with antennas 21A-23A of equal length respectively. The boosters 11 and 21, 12 and 22, and 13 and 23 constitute respectively a couple of repeaters and the repeaters are connected in cascade by coaxial cables 31, 32 of a prescribed length for exclusive reception and transmission. Thus, the dispersion in the transmission/reception level caused by the unarrangement of distance from the antenna till the repeater is eliminated, the band noise is reduced by making the band width narrow to improve the S/N. Moreover, since the system consists of transmission/reception exclusive repeaters and the coaxial cables, the interference between the signals is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a wireless relay system for transmitting information over a wide area in a weak electric field at or below the regulated value under the Radio Law.

(Prior Art) For example, in a paging wireless system in which wireless communication is performed in a weak electric field, a relay device as shown in FIG. 3 has conventionally been used to compensate for a drop in transmission level.

This includes multiple antennas la of different lengths.

1b is connected to the booster 3 via the distributor 2, and the necessary number of booster units are connected in cascade. For this reason, since the distances from each antenna to the booster are different, the levels of the transmitted and received signals at the booster are not uniform, and as long as a single amplifier is used in the booster, the transmitted and received levels cannot be adjusted efficiently. It was difficult to keep the electric field strength within the allowable range.

Also, since one line is shared for transmitting and receiving signals, a separator for transmitting and receiving signals is required.

In this part, the transmission efficiency was reduced.

These causes a reduction in the S/N of the transmission and reception lines, and variations in the transmission and reception signal levels, resulting in an unavoidable deterioration of communication conditions.

(Problems to be Solved by the Invention) As mentioned above, in order to enable clear communication over a wide range, repeaters must be appropriately placed within the service area, and the transmission and reception at these repeaters must be properly arranged. It is necessary to equalize the levels, and the present invention aims to solve this problem.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a booster that integrates an antenna and an amplifier exclusively for transmission and reception within a service area according to the strength of the weak electric field to be transmitted and received. The present invention is characterized in that a required number of boosters are arranged in cascade connection via coaxial cables so as to equalize transmission and reception levels and prevent interference between signals.

In the present invention, a necessary number of boosters that are integrated with antennas and amplifiers for transmission and reception are arranged in series within a service area, the distance from the antenna to the booster is set to a certain length, and the transmission and reception Since the signals are separated by a coaxial cable, the transmission and reception levels may vary due to uneven distances.

It is possible to prevent interference between signals.

(Example) FIG. 1 shows a connection configuration of an embodiment of the present invention.

Boosters 11-13 are comprised of receive-only amplifiers, and are each equipped with antennas IIA to 13A of equal length. 21-2
Reference numeral 3 denotes a booster consisting of a transmission-only amplifier, each of which is equipped with antennas 21A to 23A of equal length. Each of these boosters 11, 21, 12, 22, 13, and 23 constitutes a pair of repeaters, and a predetermined length of reception is provided between each repeater.

They are connected in cascade using coaxial cables 31 and 32 dedicated for transmission. 4 is connected to 1, for example, a parent device of a wireless paging device on the main body side. 5 indicates the connection to the next stage booster.

Since the present invention has a configuration in which antennas IIA-13A and 21A to 23A are directly installed in booster storage cases IIK, 12, and 13K, the output and input from the antennas attached to each booster are almost unified, which reduces noise. Occurrence is low.

Since this is a repeater that integrates a booster with an antenna and an amplifier for use only in transmission and reception, variations in transmission and reception levels caused by uneven distances from the antenna to the repeater are eliminated, and By narrowing the bandwidth, band noise is reduced and S/N is improved. Also.

Since it is composed of a repeater for sending and receiving, and a coaxial cable, interference between signals can be prevented.

FIG. 2 shows a layout diagram when the present invention is implemented in a wired and wireless paging device installed in a coal-fired thermal power plant. (I) is the indoor side, where there is an indoor boiler building M (Ia) and a turbine building M (Ib), and here there is a wired paging device 1.
A parent device of wireless paging device a and a parent device of wireless paging device 2b are installed. The wired paging device i1a is connected to the branch box 11a.
A handset station (H) 12a and a calling speaker 1 are installed at required locations on the indoor side and outdoor side (IT).
3a is placed. In addition, the wireless paging device 2b
From the parent device, the booster 21b (level corrector...repeater), which is an integrated antenna and amplifier for transmitting and receiving shown in Figure 1, is placed at the required location, as shown in the circle with the dotted line. It has a service area. In this case, the length of the coaxial cable that connects the repeaters should be determined in two ways, for example 150 m and 250 m, to avoid a reduction in the communication distance due to buildings on the premises and the length of the cable when laying between buildings on the premises. can cope with the increase in Additionally, the amplification factor of the repeater can be changed depending on the length of the coaxial cable, making it easy to make adjustments on site.

As seen in this embodiment, the wireless relay system of the present invention is installed at approximately the center of the service area, and the necessary number of relays are connected in cascade using coaxial cables depending on the spread of the service area to configure the system. In this case, the area for transmitting and receiving is determined based on the permissible range of electric field strength stipulated by the Radio Law, so the radius around the repeater, for example 80 m, corresponds to that area (the area surrounded by the round dotted line). The distance between two adjacent repeaters is in this case a maximum of 160 m. The repeater amplifier has an amplification degree that compensates for signal transmission loss in the coaxial cable between adjacent repeaters, so that the radio waves emitted from each antenna are approximately the same within the regulated electric field strength. The same is true when the signal is received from the antenna.

(Effects of the Invention) According to the present invention, a booster integrally constructed from an antenna and an amplifier dedicated to transmitting and receiving is used as a repeater under a weak electric field to equalize the transmitting and receiving levels. It is possible to improve the signal-to-noise ratio by preventing interference between signals. In addition, by cascading repeaters, it is possible to expand the service area, and it is possible to transmit operation commands to large premises such as noisy coal-fired power plants, and to transmit information by voice. suitable for

[Brief explanation of the drawing]

Fig. 1 is a connection configuration diagram of an embodiment of the present invention, and Fig. 2 is a diagram showing the connection configuration of an embodiment of the present invention. FIG. 3, a side view of the arrangement implemented at a power station, shows an example of a conventional repeater. 11, 12.13...reception booster, 21, 22.
23... Transmission booster. LLA, 12A, 13A...Receiving antenna, 21A
, 22A, 23A...~transmission antenna, 11, 12
, 13K... booster storage case, 31, 32...
·coaxial cable.

Claims (1)

[Claims] A booster that integrates an antenna and an amplifier exclusively for transmission and reception is used to equalize the transmission and reception levels within the service area according to the strength of the weak electric field to be transmitted and received, and to prevent interference between signals. A wireless relay system in a weak electric field characterized by cascading and arranging the required number of coaxial cables.