JPS59126330A - Training system - Google Patents

Abstract

PURPOSE:To increase the pull-in range of an automatic equalizer by synchronizing completely a collation pattern with a training pattern and setting the pulse intervals of a training signal longer than the tap length of the automatic equalizer so as to converge distortion. CONSTITUTION:The output of a pattern generator 6 and the output of an A/D converter 4 are inputted to the automatic equalizer 7, which collates the output of the pattern generator 6 and sets a tape coefficient so that the training signal coincides with the pattern of the pattern generator 6. This training signal is sent through a transmission line 8, then this signal is distorted on the transmission line 8 to have a hunting waveform. This hunting distortion has such intervals that no influence is exerted upon other pulses, so a pulse having a positive maximum multivalued level higher than the threshold voltage is detected by a threshold voltage circuit 5. Therefore, the timing of the training signal coincides with the timing of the output of the pattern generator 6 completely and the pull-in range of the automatic equalizer 7 is increased to shorten the leading-in time.

Description

[Detailed description of the invention] (a) Technical field of origin 9fJ The present invention transmits a training signal from an opposing multilevel transmission device prior to data transmission, and the multilevel transmission device that receives this transmits an analog signal. <In other words, by the multilevel transmission system that sets the tap coefficients of the 11 equalizer, υ and ν
) It relates to a training method that can enlarge the pull-in range of the equalizer and ensure equalization.

(b) Technical background In the case of multilevel transmission, the level interval is generally narrow, so data transmission
, F:/Bn/TX6壬1. Shibu 1++ Q-^ h
- In the case of data transmission, the tap coefficients are changed slightly based on the established tap 2 (・) to make the Yp etc. smooth and fast ( There is a lot going on.

(C) Conformity Shuttle Technique and Problem Fu The conventional training method is to receive the training signal and determine the tap coefficient of the automatic fixture without comparing it with the signal of the same pattern as L.Lening Butsugetsu. There is a method of determining the tap coefficients of the t11 equalizer by comparing same pattern signals. In either case, a binary random pattern with maximum positive and negative values is generally used as the training signal.

For this reason, in the case of one party, if there is a large gap in the transmission line, the automatic equalizer's polarity signal and error signal will be incorrectly estimated, the pull-in range will be small, and the pull-in will be slow. In the case of
Since one pulse affects other pulses and the distortion is 17, synchronization with the matching pattern becomes Tahara, and depending on the timing at which the matching pattern is generated, there is a drawback that the signal may diverge depending on the timing at which the matching pattern is generated. .

(dl Objective of the Invention 1 Objective of the Invention U Considering the above disadvantages, it is possible to completely synchronize the matching pattern with the training pattern by comparing it with the matching pattern. To provide a training method that can enlarge the retracting range of fixtures by setting the interval at which the distortion converges more than the tap of the fixture.

(e) Structure of the Invention This invention) dTraining G to achieve the above objectives
' M pattern, after n symbol clocks when the positive signal converges during transmission, a positive maximum multi-level pulse is sent for one symbol clock, and after the next 2n symbol clocks, a negative pB large multi-level pulse is sent out. for one symbol clock, then for the next n symbol clocks and the previous l]
, 2nn symbol clock shell] '娃1, multivalued number or odd,
In the case of 〇 level, Isho F's lI,! '1, the output of the analog/digital transformer of the 3-1 rule is sampled by the output IC1 of the training Shingetsu. Then, the average value of the highest value and the second largest value of π is J% (, + value voltage, and the upper 2nd training signal starts from the highest value of 1/bell). This training method is characterized by starting a pattern generator that generates the same pattern as , and setting tap coefficients by comparing the output of this pattern generator in the automatic equalizer.

(f) Embodiment of the Invention 1 Hereinafter, according to an embodiment of the present invention, the song interval is determined according to the diagram. In the case of (n4?), (R
1 indicates a case where the multilevel number is 7 (odd number). FIG. 2 is a block diagram showing the circuit configuration of the main part of the embodiment of the present invention, and FIG. 3 shows the waveform when the training signal of FIG. 1(A) follows the transmission path.

4- In the figure, the training signal pattern generator of the IU sender@ll, the 2-digit low-frequency P wave 2F, 3 the amplifier, the 4σ analog-digital transformer (referred to as the A/D transformer under JSO) )5 i1
1',! , , i-value frost pressure circuit, 6 indicates a pattern generator, 7-digit automatic equalizer, and 8-digit transmission line.

One period of the repetition pattern of the training signal used in the case of the present invention is the time n required for the distortion due to the transmission path of the pulse of one symbol clock of the maximum multi-value level to converge, as shown in Figure (A) Q3). Assuming symbol clock, n
After the symbol clock, a pulse with the maximum positive multi-value level of 1/bell is sent out for one symbol clock, and after the next 2n symbol clock, a pulse with the maximum multi-value level at the corner is sent out for one symbol clock (7); During the next n symbol clock and the previous n and 2n symbol clocks, if the multivalue number is an odd number, the O level is maintained, and if the multivalue number is an even number, the DC balance is maintained. , A), between the first n symbol clock and the next n symbol clock, the level is -172, and between the next n symbol clock and the next n symbol clock, the level is +1/2.

In a multi-purpose transmission system on the transmitting side, the above pattern is used as a training signal to generate the pattern IF'''C and low + l.
The signal is transmitted to the multilevel transmission device of the receiver 1 through the transmission line 8 of the I-wave transmitter 2. The name of the 1 ('transmission and control) is that the training signal is sent through the A/D converter to sample the analog signal into a digital signal, and then the automatic equalizer 7 and Iih The value is input to the voltage circuit 5.

nj'l 奥t-: In the pressure circuit 5, the average value of the maximum value and the second maximum value of one cycle of the training signal obtained by sampling is set as the Imf value voltage, and the training signal delay is this original one-value market. The pasting force exceeding the pressure is sent to the pattern generator 6. The pattern generator 6 starts with this output, but the pulses emitted by the pattern generator 6 start from the maximum positive multilevel level of A when shown in FIG. K is designed to generate a digital signal with the same pattern as B). The output of the pattern generator 6 and the output of the AID converter 4 are input to the self-loss equalizer 7, the output of the automatic equalizer 7 pattern generator 6 is compared, and the training signal is applied to this pattern generator. Set the tap coefficient to pass the pattern of 6. When the training signal of the pattern shown in FIG. 1 (A) is sent through the transmission line 8, it is distorted in the transmission line 8, and as shown in FIG. At the rising and falling points of , a hunting waveform appears as shown in the figure. However, in the pattern used in the present invention, the hunting distortion is spaced apart so as not to affect other pulses, so the threshold voltage circuit 5 can reliably grasp the pulse with the maximum positive multilevel level that exceeds the threshold voltage. . In addition, the one-level voltage is determined by sampling the maximum (iN) and the average value of the second maximum value, that is, the pulse of the maximum positive multilevel level during the first cycle of the training signal, that is, a in Fig. 3. It is determined by the maximum value of the obtained values and the average value of the second maximum value, and even if the hunting distortion is large, it will not be wrong to find the maximum positive multivalue level of the period b in Figure 3 below. do not have.

Therefore, the timing of the training signal and the output of the pattern generator 7-tar is perfectly matched, and since there is no influence of the output of the 1-horn pulse or the 11-pulse, the pull-in range becomes wider and the pull-in range becomes wider. Time also becomes faster. Furthermore, since a DC-balanced pattern is being sent, even if the phase of the carrier in the OI section (not shown in Figure 1) of the multilevel transmission device is shifted by 180 degrees and the sheath of the received signal is reversed, v: Nosakugen's work will decay in exactly the same way.

(g) The seeds of the invention As described in more detail, according to the present invention, the self-weight j1 equalizer reliably determines the tap coefficient, and also widens the training signal pull-in range and shortens the pull-in time. It has the effect of making it faster.

[Brief explanation of drawings]

Figure 1 shows the training signal pattern of the embodiment of the present invention, Figure 2 shows the key tone 1 of the embodiment of the present invention.
FIG. 3j is a block diagram showing the circuit structure of FIG. [1st part is a pattern generator, 2 is a low-frequency p-wave generator.
13-digit amplifier, 4-digit analog/digital converter, 58
6 indicates a pattern generator, a 7-digit automatic equalizer, and an 8-digit transmission line. Abominable phrase υ 〜++ Q −NjwaΔwashing−E! −)

Claims (1)

[Claims] Prior to data transmission, training issue 41 is transmitted from the opposing multi-value transmission device 1, and the multi-value transmission that receives it ξts: In the multilevel transmission system 1/r that sets the tap coefficient it/ of the 11t1 converter, the pattern of the training signal is
At the n-symbol clock at which the distortion due to the transmission path converges, a pulse with a positive multivalue level is sent out 1 [11] after one symbol clock, and at the next 20 symbol clock f
Send a pulse with a high level of "k" for one symbol clock, then send it to jkl of the next n symbol clock, 2n symbol clock Ldl pl B1 Set the DC balanced level to Assign 17 signals,
Anagro digital of HI4ir lil+: mta
A-Large candy obtained by sampling the r training signal and 2:? The average of the maximum values of the Gth
i7+i 41 ra'...pressure, the μ training signal exceeds the 1+bη9' pressure and outputs an output for the fCC line 4) Sen'
A pattern generator 1/1 that has a city pressure cycle and generates the same pattern as the training signal starting from the positive μ large-scale level of the training signal with this output.
- A training method characterized by starting the evening and setting the tap temperature by comparing the output of this pattern generator with a self-sufficient 11 equalizer.