JPS5852375B2 - Ocean interval equalization method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for inserting an equalizer in an ocean section equalization system of a submarine coaxial cable transmission system.

Conventionally, ocean section equalization systems for submarine coaxial cable transmission systems have been designed by focusing on the relationship between equalization degree deviation and noise margin degradation that occur in submarine relay transmission lines, and the insertion interval of ocean section equalizers has been determined. .

For example, in the C8-36M system (Electric Corporation), the insertion interval of the ocean section equalizer is determined by paying attention to the equalization degree deviation and noise margin deterioration.

(Tabata, Ide, Hakamada: “Overview of the C8-36M system”, Tsuken Jitsho Vol. 23/163, P366 (1974),
(Reference) However, as submarine relay transmission lines have become more limited in their overload margins due to broadband transmission systems, equalizer insertion intervals are determined using conventional design methods that focus on equalization degree deviation and noise margin deterioration. It has become impossible.

That is, if an equalizer is inserted using the conventional geometric design method, the repeater will be overloaded.

The overload margin limitation of submarine trunk transmission lines can be explained by the following phenomenon.

Figure 1 shows the 100M transmission band currently under research at the Telegraph and Telephone Public Corporation.
This figure shows the relationship between the equalization degree deviation, noise margin deterioration amount, and overload margin deterioration amount that occurs in the submarine relay transmission line of the large-capacity submarine coaxial cable transmission system exceeding Hz.

Comparing the equalization degree deviation accumulated in accordance with the number of relays in Figure 1a, the noise margin deterioration in Figure 1S, and the overload margin deterioration in Figure 1C, it can be seen that with the same number of relays, the amount of overload margin deterioration is equal to the noise margin It can be seen that this is much larger than the amount of deterioration.

For example, the amount of noise margin deterioration in 50 relays is about 3 dB, but the overload margin deterioration amount is as large as about 9 dB.

In other words, it can be said that as the bandwidth of the system becomes wider, the overload margin of submarine relay transmission lines is becoming limited.

Therefore, an object of the present invention is to deal with the overload margin limitation of submarine relay transmission lines due to the broadbandization of submarine coaxial cable transmission systems, and to fix the insertion interval of each equalizer to an integer of the equalizer insertion interval. The object of the present invention is to provide an ocean section equalization method using an equalizer in an orderly manner.

The present invention utilizes a fixed equalizer, a semi-fixed equalizer, a variable equalizer, etc., which are components of the ocean section equalizer, in an ocean section equalization method that compensates for equalization degree deviations occurring in submarine relay transmission lines. determine the insertion interval of each equalizer, and insert any combination of the above three types of equalizers, or all the equalizers, in accordance with the insertion interval of the fixed equalizer. It is characterized by being built into the ocean section equalizer.

Examples will be described below with reference to the drawings.

Figure 2 shows the principle of the present invention, where 1 is a landing station, 2 is a submarine relay transmission line (consisting of repeaters and cables), and 3 is a landing station.
is a fixed equalizer, 4 is a semi-fixed equalizer, 5 is a variable equalizer, 6
is an arrow indicating adjustment of the insertion interval, and this 6 is the key point of the principle.

Here, the fixed equalizer 3 compensates for design and manufacturing deviations of repeaters and cables that are obvious equalization degree deviations before installation,
The semi-fixed equalizer 4 compensates for cable handling effects, which are equalization degree deviations caused by installation, and the variable equalizer 5
This compensates for changes in cable attenuation over time, which are equalization deviations that occur after installation, and changes in repeater gain and cable attenuation due to seasonal changes in seawater temperature.

If the overload margin of the method is weighted and distributed to three types of equalizers: fixed equalizer, semi-fixed equalizer, and variable equalizer, the insertion interval of each equalizer is It is determined according to the amount of overload margin deterioration per unit relay section due to the equalization degree deviation to be compensated.

However, if the weights were simply distributed, as shown in Figure 2 (because there is no relative relationship between the insertion intervals n+o, nzo, and n3o (relay) of each equalizer, the equalizers would be installed irregularly on the seabed. This is a practical disadvantage.

Therefore, in the present invention, as shown by arrow 6 in FIG. 2, the insertion interval n20 of the semi-fixed equalizer and the insertion interval n3 of the variable equalizer are
The key point of the principle is to adjust o to an integral multiple of the insertion interval nlO of the fixed equalizer, and the ratio of the insertion intervals of the fixed equalizer and variable equalizer is applied as a parameter for weight distribution.

However, it is a matter of course that the insertion interval is adjusted within a range that satisfies the overload margin.

Now, the procedure for calculating the equalizer insertion interval, in which the overload margin is weighted and distributed to the three types of equalizers while maintaining a relative relationship between the insertion intervals of each equalizer, is shown in Figure 3 a-b, which shows the basic insertion rules. It is shown below using .

Figure 3a shows the insertion interval of each equalizer, and Figure 3a shows how each equalizer is built into the ocean section equalizer and connected to the submarine relay transmission line based on the results of Figure 3a. This shows the case of regular insertion of 1°.

Of the ocean section equalizers, 7 consists of only fixed equalizers, and 8
9 shows the configuration of a fixed equalizer and a semi-fixed equalizer, and 9 shows the configuration of a fixed equalizer and a variable equalizer.

Note that each symbol used in calculations is defined as follows.

However, N, nl, n2, n3 are unknown numbers, a, b,
, c, OM are known numbers.

N (=n3/n1): Fixed equalizer and variable equalizer insertion interval ratio, nl: Fixed equalizer insertion interval (relay), n2: Semi-fixed equalizer insertion interval (relay), n3 : insertion interval of variable equalizer (relay), a: amount of overload margin deterioration per unit relay section due to equalization degree deviation to be compensated for by fixed equalizer (dB)
, b: Overload margin deterioration amount (dB) per unit relay section due to equalization degree deviation to be compensated by the semi-fixed equalizer, c: per unit relay section due to equalization degree deviation to be compensated for by the variable equalizer The overload margin deterioration amount (dB) of OM2 and the overload margin (dB) of the two OM methods.

[Step 1] Upper limit value N of the insertion interval ratio N.

Calculation However, [ ] is a Gaussian symbol [Procedure 2] Range clarification of parameter N nl is obtained by dividing overload margin OM by the amount of overload margin deterioration of each equalizer in the case of insertion interval ratio N.

However, it is assumed that a semi-fixed equalizer exists in the ocean section equalizer located before the variable equalizer.

[Step 4] Based on the result of the variable equalizer insertion interval n3 calculation formula (3), n3 is calculated as follows from the definition of the insertion interval ratio N.

n3-N-nl (Relay) (4) [Step 5] Semi-fixed equalizer insertion interval n2 calculation (RIOM-(
If an1+en3)<bn3, then n2≦(N-1)n
l (Relay) (5) (!riOM (an1+cn3)≧bn3 if n2
≧N-n1=n3 (Relay) (6) [Step 6] Selection of optimal insertion interval ratio N Select the optimal insertion interval ratio from among the insertion intervals of each equalizer in the range of N=1 to NmaX.

The criteria for selecting the optimal insertion interval ratio N include (a) the minimum total number of equalizers, (0) the minimum number of equalization numbers for ocean sections, and the minimum number of variable equalizers. Whether it is adopted depends on the area in which the method is applied.

The insertion intervals n2 and n3 of the semi-fixed equalizer and variable equalizer obtained in steps 1 to 6 above are calculated using equations (4), (5), and (6).
As shown, it can be seen that it is an integral multiple of the insertion interval n1 of the fixed equalizer.

As explained above, the present invention focuses on the fact that submarine relay transmission lines are becoming limited in overload margin due to the broadbandization of submarine coaxial cable transmission systems. The insertion intervals of the three types of equalizers described above are determined by allocating overload margins to the equalizers, and it can be said that this is an ocean section equalization method that can cope with wide-band implementation.

In particular, a combination of equalizers, or all three types of equalizers, which are ocean interval equalizer components, fixed equalizer, semi-fixed equalizer, and variable equalizer, or all three types of equalizers, It can be incorporated into the ocean section equalization whose insertion interval matches the insertion interval of 1 (Fig. 3b).

As a result, the ocean section equalizer can be inserted into the submarine relay transmission line periodically, making installation easier.

Furthermore, since the ocean section equalizer incorporates a plurality of the three types of equalizers mentioned above, the number of ocean section equalizers to be inserted can be significantly reduced compared to the total number of each equalizer to be inserted, resulting in economic efficiency. It has other practical advantages.

In addition, the extra space of the ocean section equalizer 7, which shows the configuration of only a fixed equalizer in Figure 3, is not limited to a semi-fixed equalizer that compensates for unpredictable equalization degree deviations before installation, or a phase etc. An application example is possible in which a group delay equalizer that performs the equalization is built in.

[Brief explanation of drawings]

Figure 1a shows the equalization degree deviation that occurs in the submarine relay transmission line of the large-capacity submarine coaxial cable transmission system with a transmission band exceeding 100 h. FIG. 1C is a diagram showing the amount of overload margin deterioration in the transmission line of FIG. 1a, FIG. 2 is a diagram explaining the present invention in detail, and FIG. FIG. 3 is a diagram showing the insertion interval of each equalizer after adjusting the insertion interval of the equalizer, and FIG. 3 is a diagram showing a state in which each equalizer is built into the ocean section equalizer according to the present invention. . 1... Landing station, 2... Submarine relay transmission line (consisting of repeaters and cables), 3... Fixed equalizer, 4... Semi-fixed equalizer, 5...variable equalizer, 6...arrow indicating adjustment of isovolume insertion interval, 7...configuration of only fixed equalizer ocean interval equalizer, 8... ocean interval equalizer composed of a fixed equalizer and a semi-fixed equalizer, 9...... fixed equalizer and variable equalizer An ocean interval equalizer consisting of.

Claims (1)

[Claims] 1. The overload margin of the submarine coaxial cable transmission system can be reduced by using a fixed equalizer that compensates for obvious equalization degree deviations before installation, which are components of the ocean section equalizer, and a semi-equalizer that compensates for equalization degree deviations caused by installation. The equalization degree deviation that each equalizer should compensate for the overload margin distributed to each equalizer by weighting and distributing it to the fixed equalizer and the variable equalizer that compensates for the equalization degree deviation that occurs after installation. Divide by the amount of overload margin deterioration per unit relay section by
An ocean section equalization method that determines the insertion interval of each equalizer into the submarine relay transmission line by rounding down the decimal point board to an integer, and the insertion interval ratio (integer) of the fixed equalizer and variable equalizer. By using as a parameter, first determine the insertion interval of the fixed equalizer and variable equalizer such that the insertion interval of the variable equalizer is an integral multiple of the insertion interval of the fixed equalizer, and then determine the insertion interval of the semi-fixed equalizer. By setting the insertion interval of the semi-fixed equalizer and the variable equalizer to be an integral multiple of the insertion interval of the fixed equalizer, An ocean section equalization method characterized in that an ocean section equalizer, a semi-fixed equalizer, and a variable equalizer are built into an ocean section equalizer that is inserted in accordance with the insertion interval of the fixed equalizer.