JPS63292832A - Radio communication system using stranded pair type leakage cable - Google Patents

Abstract

PURPOSE:To match and synthesize phases only by an equipment possible to be constituted of a passive device such as a phase shifter and a distributor, by using an insulator commonly by each pair of conductors of a crosstalk cable consisting of the pair of conductors, and stranding the cable with the same waveform reduction ratio and the same pitch. CONSTITUTION:The conductors 1 and 1' and the conductors 2 and 2' form pairs respectively, and are stranded with the same pitch in the longitudinal direction of the cable, and leakage functions are attached on them. A high frequency power outputted from a radio equipment 5 is bi-sected equally by the distributor 4, and one is coupled with a second pair 2-2' of conductors. And the insulator 8 is used commonly by a first pair 1-1' of conductors and the second pair 2-2' of conductors. Therefore, the waveform reduction ratio of them are quite equal, and since they are stranded with the same pitch, the pair 1-1' of conductors and the pair 2-2' of conductors are the leakage cables equivalent to each other. The phase difference of waves received by each pair of conductors is always constant, and is decided uniquely by the structure of the cable. Therefore, phase matching between each pair of conductors can be performed by inserting the phase shifter 3 with a constant value and correcting the phase difference.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention is a wireless communication system using a twisted nine-pair leaky cable, and is used in areas where there are many obstacles in the surrounding area.

As shown in Figure 2, there is a type of conductor in which a pair of conductors are twisted together with a constant bit. When a cable is installed in a tunnel, underground mall, etc. and used as an antenna, nearby structures reflect the radio waves, and as a result of interference between the two radio waves, the electric field distribution becomes distorted. If you move the receiver along the cable while maintaining a constant distance from the cable, the reception level will vary depending on the electric field strength at that location.

FIG. 3 is an example of this, in which the horizontal axis represents the moved point in terms of distance, and the vertical axis represents the output reception level. .

The reception level fluctuates with a period close to the length of the cable's twisted pips, dropping to significantly lower levels at certain points. If the output of the oscillator is low, the required level of received power will not be obtained at this point, and communication will be interrupted.

As a method to solve this problem, a wireless communication system using a multi-conductor twisted nine-pair leaky cable has been proposed. Figure 4 is a block diagram using the proposed communication method, in which a twisted 9-pair leaky cable with multiple insulated conductor pairs (4 in this example) and 10 conductor pairs are set up, and this is used as an antenna. , the respective received signal outputs are demodulated separately by a demodulator 11 and a demodulator 12, and the demodulated signals are applied to a combiner 13, and the electric field characteristics of the conductor pair 9 and 10 are completely adjusted at the combining point to the output terminal 14. Since they never match, the output of the demodulator will never be the same value at the same time. Therefore, even if the signal output of one demodulator becomes significantly low, the signal output of the other demodulator does not become so low, and the combined output is a combination of both, so that no significant decrease in signal output occurs.

[Problem that the invention seeks to solve]

This type of method requires a separate demodulator, that is, a radio device for amplified detection, to correspond to each can, so the number of radio devices required is logarithmic, which has the drawback of increasing the cost of the entire device. Furthermore, when radio waves from the antenna of a leaky cable are received by multiple conductor pairs, combined, and input to a demodulator, if the wavelength shortening rate and pitch of each conductor pair are different, the radio waves received by the conductor pair will vary depending on the antenna position. p11 with different phase differences between the conductor pairs
Depending on how the level received by the conductor pair changes, the correlation between the conductor pairs disappears. As a result, when combining the received radio waves of each conductor pair, in order to make the phase continuous and to efficiently receive high-level radio waves, we need to detect the phase difference and level difference of the received radio waves between each conductor pair. equipment is required, making the synthesis equipment complex. Furthermore, if there are multiple leaky cables, it is necessary to provide a combining device for each cable. This method also has drawbacks such as being effective only when the leaky cable is a receiving antenna.

[Means for solving problems]

In the present invention, an insulated conductor having a common insulating material applied around the conductor is twisted and twisted in the length direction at a pitch of about one electrical wavelength used for communication; two conductors selected from the multi-conductor Then, multiple conductor pairs are created, and each pair of leaky cable is used as an antenna. Each pair of received radio waves is made into the same phase radio waves through a phase shifter that changes the phase individually, and then they are combined (distributed in the case of a transmission system) by a distributor with a certain distribution ratio. Provides a wireless communication method that

〔Example〕

FIG. 2 is a block diagram illustrating a detailed explanation of the invention adopted in Section 1d, and FIG. 2 is a perspective view of a multi-conductor twisted pair leaky cable used in the invention, with the cable jacket removed.

The conductors 1 and 1' and the conductors 2 and 2' form pairs, respectively, and are twisted in the longitudinal direction of the cable with the same bits to provide a leakage function. The high frequency power emitted from the radio device 5 is divided into two parts by a distributor 4, and one part is coupled to the second pair of conductors 2-2'. The remaining half is coupled to the first conductor pair 1-1' with a phase delay of 90° by a phase shifter 3. However, 1°2 is the positive side 1' and 2' is the negative side.

On the cross section of the cable, the first conductor pair 1-1' and the second conductor pair 2
-2' is a house-shaped cable arrangement, and the angle formed by both elbows is 90°. Since the first conductor pair 1-1' and the second conductor pair 2-2' share the insulator 8, their wavelength shortening rates are exactly the same, and since they are twisted with the same bits, , conductor pair 1-1', 2-2' are completely equivalent leaky cables.

Fig. 2 is a cross section of the radio device 5, looking at the cable, and the second conductor pair 2-2' is twisted from the first conductor pair 1-1' by the length of the gutter. It is equivalent to moving in the opposite direction. Therefore, the radio waves received by the second conductor pair 2-2' are different from the radio waves received by the first conductor pair 1-1'.
Each conductor pair of a crosstalk cable consisting of a wireless conductor pair with a phase delay of 90 degrees shares the insulator 8 as in the embodiment, and is twisted with the same wavelength shortening rate and the same bit, so that the received radio waves of each pair are Phases can be combined only with devices that can be configured with passive elements such as phase shifters and dividers that can be used for both transmission and reception.

[Brief explanation of drawings]

Fig. 1 is a block diagram of the wireless communication system of the present invention, Fig. 2 is a perspective view showing the internal structure of the leaky cable used in the present invention, and Fig. 3 is parallel to the twisted 9-pair leaky cable and along the cable. Figure 4 is a block diagram of a mourning radio system using a multi-conductor twisted-pair leaky cable. Figure 5 is a diagram of the reception level of the moved radio. Figure 5 shows the results of each conductor when the twisted 9 pips of the conductor pair are shifted from each other. It is a diagram of a pair of reception levels and their combined reception level. FIG. 6 is a block diagram of an embodiment of the present invention. 1.1', 2.2'--Conductor 1-1'--First conductor pair 2-2'--Second conductor pair 3...Phase shifter 4...1 distributor 5 . . . Radio equipment 6 . . . Terminator 7 . . . Pair leakage cable 8 .・Output terminals 24, 25-... Phase shifter II
aO received bell diagram 3rd figure C9Δ・〈chamber

Claims (1)

[Scope of Claims] A multi-conductor pair comprising insulated conductors formed by applying a common insulator around the conductors and twisted in the length direction at a pitch of about one electrical wavelength used for communication; A plurality of conductor pairs are created using two conductors selected from the conductors, and the twisting pitch and wavelength shortening rate of the pairs are equal, and the directions of the straight lines connecting the paired conductors in the cable cross section are different from each other. Equipped with a leaky cable as an antenna; Equipped with a phase shifter that changes the phase of the received signal received by each conductor pair of signal radio waves; Equipped with a phase shifter that changes the phase of the received signal for each received signal; The output signal of the phase shifter is distributed at a fixed distribution ratio. A wireless communication system using a twisted-pair leaky cable, including a splitter; the phase shift amount of the phase shifter is selected so that the radio waves received by each pair are input to the wireless input/output terminal in the same phase.