JPH02202728A - Line equalizing system - Google Patents

Abstract

PURPOSE:To reduce the constitution of a circuit, and also, to decrease the fault rate by providing a level detecting part, a deciding part, a line equalization adjusting part and an identifying part, bringing automatically an input signal to the identifying circuit to optimum correction and sending it out. CONSTITUTION:As for an input signal 2 inputted to a terminal 1, a line loss is generated due to a signal speed, etc., and its level is varied. A level detecting part 3 detects the level of the signal 2 and outputs a level result signal 4 to a deciding part 5. The deciding part 5 does not cause a malfunction by some level fluctuation since it has a hysteresis characteristic, and outputs a line equalization value deciding signal 6 to a line equalization adjusting part 7. The adjusting part 7 adjusts a line equalization value of the signal 2 and outputs a line equalizing signal 8 to an identifying circuit 9. The circuit 9 compares the inputted signal 8 and a constant reference voltage, but since the signal 8 is adjusted by the adjusting part 7, even if an input data level is varied due to a line loss, it is identified without causing a read error, and a contents processing signal 10 is outputted. In such a way, an optimum correction of the input signal is automatized, and the reduction of the constitution and the decrease of a fault rate can be executed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a line equalization method that automatically and optimally corrects line loss due to signal speed, line length, or wire material.

[Conventional technology]

Conventionally, this type of line equalization method has prepared several types of identification thresholds, and has used an identification threshold switching method and a peak value detection circuit that correct line loss by switching the identification thresholds.

A variable equalization amplification method has been proposed that corrects line loss by combining an automatic gain control circuit (AGC), a variable equalization amplification circuit, and the like.

[Problem to be solved by the invention]

The above-mentioned conventional line equalization methods, especially the discrimination threshold switching method, require adjustment of their discrimination thresholds.

Further, the variable equalization amplification method has drawbacks such as an increase in the number of automatic gain control circuits and variable equalization amplification circuits.

[Means to solve the problem]

The line equalization method according to this output signal includes: a level detecting means for detecting the level of an input signal and outputting a level detection result signal; a determining means for outputting a line equalization value judgment signal from the level detection result signal; and identification means for determining the line equalization value of the input signal using the line equalization value determination signal and outputting a line equalization signal.

[Effect]

The line equalization method of Jin's invention can more fully cope with the problem than by switching the line equalization value in several stages.

〔Example〕

The figure is a block diagram showing an embodiment of the line equalization method according to the present invention. In the same figure, a terminal 3 receives an input signal 2 whose level changes depending on the length of the twisted line, and a terminal 3 has a function such as peak detection, detects the level of the input signal 2 input to the terminal 1, and outputs a level detection result signal 4. 5 is a determination unit having a hysteresis characteristic that operates upon input of this level detection result signal 4 and outputs a line equalization value judgment signal 6; T is an input of this line equalization value judgment signal 6; ) The line equalization value of input signal 2 is a*U,
For example, when the line length is long and therefore the input signal 20 level is small, K will reduce the line equalization value by the line equalization value judgment signal 6, and when the inverse KM path length is short and the input signal 20 level is large, K will equalize the line. A line equalization adjustment section operates to increase the line equalization value (according to the value judgment signal 6) and outputs a line equalization signal 8, and 9 compares the input line equalization signal 8 with a constant voltage 7 This is an identification circuit such as a line receiver that outputs a signal 10 for internal processing.

Next, the operation of the line equalization method with the above configuration will be explained. First, terminal IK, the input signal 2 to be input is the signal speed,
Line loss occurs depending on the wiring length or wire material, and the level changes. The level detection section 3 detects the level of the input signal 20 and outputs a level detection result signal 4 to the determination section 5.

This determination unit 5 operates based on the input of the level detection result signal 40, but since it has hysteresis characteristics, it does not malfunction even with slight fluctuations in the input signal 2, and the line equalization value determination signal 6 is equalized. It is output to the adjustment section 7. As described above, the line equalization adjustment unit T adjusts the input signal 20 and the line equalization value to the line equalization value determination signal 6, and adjusts the line equalization value to the line equalization signal 8.
is output to the identification circuit 9.

As for the line equalization method, at low signal speeds (2 Mb/m or less), it is not necessary to perform line equalization continuously on the line length, and if the Kf characteristic can be corrected in two steps, for example, it will not be a problem for practical kits. . Also, the correction method is also based on the amplifier!
It is also possible to perform this by changing the f-characteristic, or by switching between two different types of fixed f-characteristic correctors. Then, the identification circuit S compares the input line equalization signal 8 with a constant reference voltage. Since this line equalization signal 8 has been adjusted by the line thickening adjustment section 7, the input voltage level is changed depending on the line loss. Even if the signal changes, it is identified without misreading and an internally processed signal 10 is output.

〔Effect of the invention〕

As explained in detail above, according to the line equalization method according to the present invention, the level detection section 1 stabilization section, the line equalization adjustment section a
! By combining a separate open circuit etc., automatic VCR
The input signal to another circuit can be optimally corrected and sent out, the constituent circuits can be downsized, and the failure rate can also be reduced.

[Brief explanation of the drawing]

The figure is a block diagram showing an embodiment of the line equalization method according to the present invention. 1e... @ terminal, 2... conflict/input terminal, 3...-level detection ttl, 4...-1 and bell detection result No. a, 5...
・Judgment unit, 6...611 line equalization value judgment signal, 1...φ
・Line equalization tin part, 8・Cloudy・Φ line equalization signal, 9...
...Identification circuit.

Claims (1)

[Claims] A line equalization method of a digital communication system includes a level detection means for detecting the level of an input signal and outputting a level detection result signal, a determination means for outputting a line equalization value judgment signal from this level detection result signal, and 1. A line equalization method comprising: identification means for adjusting a line equalization value of an input signal using a line equalization value determination signal and outputting a line equalization signal.