SU930732A1 - Multilevel bipolar signal regenerator - Google Patents

Description

(54) MULTILEVEL BIPOLAR REGENERATOR

one

The invention relates to telecommunications and can be used in the transmission of multi-level signals from trunk cable lines.

A multilevel bipolar signal regenerator is known, containing a linear line output driver, the gating input of which is connected to the output of the clock frequency selector, a (tt-l) information inputs {where P is the number of levels of the multilevel linear signal connected to the outputs of the corresponding threshold blocks, inputs which are combined and connected to the output of the input amplifier, the control input of which is connected to the output of the automatic gain control unit, the input of which is connected to the input of the selector clock frequency.

A disadvantage of the known device is the insufficient accuracy of restoring the temporary position.

SIGNALS

pulses of the regenerated linear signal due to the jitter of the phase of the gating pulses at the output of the clock frequency selector and the low signal power at the input of the automatic gain control unit.

The purpose of the invention is to improve the accuracy of recovery of the regenerated signals by reducing the jitter of the gating pulses, as well as increasing the signal power at the input of the automatic gain control unit.

The goal is achieved by the fact that in a multilevel bipolar regenerator, containing an output linear signal shaper, the gating input of which is connected to the output of the clock frequency selector, and (n-1) information inputs (where P is the number of levels of the multilevel linear signal) are connected to the outputs of the respective threshold units, the inputs of which are combined and connected to the output of the input amplifier, the control input of which is connected to the output of the automatic gain control unit whose input is connected not with the input of the clock frequency selector, pulse extenders, a delay element and a controlled linear amplifier, the main input of which is connected to the input of the amplifier through the delay element, the output is connected to the input of the clock frequency selector, and the control inputs linear amplifier through pulse extenders connected to the outputs of the respective threshold units.

Figure 1 shows the structural scheme of a multilevel regenerator of bipolar signals; figure 2 timing diagrams of the device-. . . - ;;.,

The multilevel bipolar signal regenerator contains an input amplifier 1, threshold blocks 2 positive polarity pulses, threshold blocks 3 negative pulse 1 rbet, 4 delay elements, output Y shaper 5 li + 1 synyy / w, 6 pulses, controlled by a linear pulse 7 with a stulench ety reduction of the gain, extract, or 8 clock frequency, block I automatic gain control.

The device works with; ice image.

A multi-level linear signal (for example, on .2a) from the output of the input amplifier t is applied simultaneously to the inputs of threshold blocks 2 and 3 of positive and negative polarity pulses, respectively, as well as to the input of delay element L When the threshold levels exceed their thresholds The 2 and 3 pulses of positive and negative polarity are fed separately to the information inputs of the output shaper 5 of a linear signal, which, when the information and gating pulse coincides, forms The output pulse is of standard duration, corresponding to polarity and amplitude. At the same time, all the decision signals (with the exception of the two decision signals

from the outputs of the threshold blocks 2 and 3 pulses of positive and negative polarity, are fed to the inputs of the expanders 6 pulses, and from the output of the latter are fed to the control inputs of a controlled linear amplifier 7 with a stepwise decrease in the gain. In this way,

The extended decision signal pulses of the threshold devices for the upper levels of the linear signal (greater than one) are control signals with respect to the controlled linear amplifier 7. The arrival of a signal at the input of its control leads to a stepwise decrease in its gain. The number of the threshold level of each threshold block of the regenerator determines the degree of reduction of the gain of the linear amplifier 7 for its control signal. For example, for the 3-level linear signal, the levels of +2, + t are determined. O, -1, -2 (Fig. 2a), the controlled linear amplifier 7 of the regenerator has only two control inputs (p-3) to make level decision signals

- 4-2 and -2 (fig.26, c), and the gain reduction factor of this amplifier when receiving control signals from the outputs of the expanders 6 pulses (Fig.) Is also equal to zero. A controlled Line Amplifier 7 with a stepwise decrease in the gain factor attenuates the gain factor by the operating time of the control signal t. The multilevel linear signal from the output of the delay element of Fig. 2e) is fed to the input of a controlled linear amplifier 7 with a stepwise decrease in the gain.

The delay of a multi-level linear signal for a time tjg L 12 provides the connection of a controlled linear amplifier 7 "to the moment of arrival of pulses with a level of +2 and 2, which are attenuated to

 pulses with a level of +1 and -t. The duration of the control signals at the output of the pulse extenders 6 is determined by the transition moment of the pulses subjected to attenuation with levels of 4-2 and -2 through the level corresponding to the maximum value of the amplitudes of the pulses with levels of 4-1 and -1 (fig.2d, e). As a result of the controlled attenuation of the pulses of the upper levels of the multilevel linear signal, a 3-level signal is generated at the output of the controlled linear amplifier 7, which is fed to the input of the clock frequency selector 8, where the jitter of the phase of the incoming pulses can be significantly reduced by the known method of limiting the amplitude used in designs of linear level regenerators. Direct application of the known method of limiting the amplitude of a linear signal pulses in a multilevel regenerator does not allow one to obtain a decrease in the phase jitter (& if and more for a 5-level linear signal with any limitations within the lower level, fig.2a}, Selection of amplitude limitation only within the upper level (for example, using only pulses with the levels of 1 2 in the 5 level Linear smg) reduces the phase jitter, but at the same time leading to a significant loss of power, the clock frequency When “4m” these losses increase dramatically with an increase in the number of levels, the uruham signal from the output of the controlled linear amplifier .7 is fed to it at the time to the input of the automatic gain control unit 9. In this way, This block uses only aiHeiirwt of the pulses of the upper levels of the multilevel linear signal, in this case the energy of all the pulses is used, and the gain of the input amplifier is determined by the average of all the levels

9307326

linear signal, which leads to an increase in the recovery accuracy of the regenerated signals.

Claims (1)

Invention Formula A multilevel bipolar signal regenerator containing a linear line output driver, the gating input of which is connected to the output of the clock frequency selector, and (n-1) information inputs (where tV is the number of multilevel line signal) connected to the outputs of the corresponding porous blocks whose inputs are combined and connected to the output of the input amplifier, the control input of which connected to the output of the automatic amplification reproduction unit, whose input is connected to the input, select the Clock frequency, which is also so that, in order to improve the accuracy of restoring regenerated signals, by reducing the jitter phase jitter, the pulse expanders, el (delay and controlled linear-amplifier, the main input of which is connected through the delay element to the output of the input amplifier. The output is connected to the input of the clock frequency selector, and (n-3) the inputs of the control unit are linear Investigate through impulse expanders С € are united with the outputs of the corresponding threshold blocks . information sources, accepted so attention during examination t. USSR author's certificate W. H 0 L 25/52,1978 (prototype). ua "SI 4 | M -t "4 d " " NS Lj