JP2856578B2 - Cross connect device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to extracts a clock timing from the NRZ (non-return-to-zero) signal, using the extracted clock timing cross-connect
To restore the original signal by inversely converting the NRZ signal
It relates to a loss connect device.

[0002]

2. Description of the Related Art Conventionally, N
In the case where the transmission speeds of the RZ signals are different, a method has been used in which separate timing extraction circuits adapted to the respective transmission speeds are prepared and switched as needed in order to extract the clock timing. Further, since one of a plurality of NRZ signals is always supplied to this type of timing extraction circuit, an unnecessary clock signal is output even when a clock is unnecessary.

[0003]

In the above-mentioned conventional method, it is necessary to prepare a plurality of timing extraction circuits separately corresponding to the respective transmission speeds of the NRZ signal. Material costs and adjustment time were increasing. Further, unnecessary power is consumed because the clock signal is always output.

Accordingly, an object of the present invention is to provide a timing extraction circuit with a filter having a plurality of resonance characteristics corresponding to each of a plurality of different transmission speeds. An object of the present invention is to provide a cross-connect device capable of extracting timing.

Another object of the present invention is to supply an NRZ signal to a timing extraction circuit and supply a reproduction clock only when an operation prohibition state of the timing extraction circuit is not indicated in response to an external control signal. An object of the present invention is to provide a cross-connect device capable of outputting a signal.

[0006]

According to the present invention, there is provided a timing extracting apparatus for converting an input signal into a signal having a speed according to the type of the signal.
Interface for converting to the first NRZ signal and outputting
And a cross-connect of the first NRZ signal.
Matrix switch for outputting the second NRZ signal.
NRZ signal and the second NRZ signal.
A timing extraction device for extracting a clock timing from the RZ signal and outputting the extracted clock timing as a reproduced clock signal ;
Inverts the original signal using the recovered clock and outputs it
And an interface transmission unit.
A cross-connect device, wherein the timing extraction device
But the signal conversion means for the second NRZ signal into a discontinuous clock signal, and filter means for the discontinuous clock signal to a continuous sine wave, the recovered clock signal to the sine wave And a filter for converting the signal into a single SAW filter having a plurality of resonance characteristics corresponding to each of the plurality of different transmission speeds.

Further, the cross-connect device according to the present invention converts the input signal to a first signal having a speed according to the type of the signal.
Interface receiving unit that converts to NRZ signal and outputs it
And cross-connects the first NRZ signal.
A matrix switch unit that outputs two NRZ signals;
A timing extraction device that receives the second NRZ signal, extracts a clock timing from the second NRZ signal, and outputs the extracted clock timing as a reproduced clock signal;
NRZ signal into the original signal using the recovered clock
And an interface transmission section for performing inverse conversion and outputting.
A cross-connect device, characterized in that
A first switch means for controlling whether or not to supply the second NRZ signal to the timing extraction circuit in response to the external control signal; in response to the signal, the a second switch means for controlling whether or not to output the reproduction clock signal extracted by the timing extraction circuit, the timing extraction circuit, the second NRZ
Signal conversion means for converting a signal into a discontinuous clock signal, filter means for converting the discontinuous clock signal into a continuous sine wave, and means for converting the sine wave into the reproduced clock signal Wherein the filter means comprises a single SAW filter having a plurality of resonance characteristics, and the first and second signals are provided only when the external control signal does not indicate the operation inhibition state of the timing extraction circuit. Switching means supplies the second NRZ signal to the timing extraction circuit and outputs the reproduced clock signal.

[0008]

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 2 is a conceptual diagram showing a cross-connect system to which the present invention can be applied. The input terminal 10 is connected to the interface receiving unit 20. The interface receiving unit 20 is further connected to a matrix switch unit 30. The signal supplied from the input terminal 10 is converted into an NRZ signal in the interface receiving unit 20. The NRZ signal converted in the interface receiving unit 20 is supplied to the matrix switch unit 30. The matrix switch unit 30 is connected to one input terminal of the interface transmission unit 50 and the timing extraction device 40. The other input terminal of the interface transmission unit 50 is connected to the output terminal of the timing extraction device 40.

The matrix switch section 30 cross-connects the supplied NRZ signal and supplies it to the timing extracting device 40 and the interface transmitting section 50. The interface transmission unit 50 is for inversely converting the NRZ signal into the original signal supplied from the input terminal 10. In order to operate the interface transmission unit 50, a clock is extracted from the NRZ signal by the timing extraction device 40, and the extracted clock timing is supplied to the interface transmission unit 50 as a reproduced clock signal. Upon receiving the reproduced clock signal, the interface transmitting unit 50
Converts the NRZ signal back to the original signal and outputs it from the output terminal 60.

Next, the timing extracting device 4 shown in FIG.
The configuration of 0 will be described in more detail.

FIG. 1 is a basic block diagram for explaining in detail the configuration of a timing extracting device 40 according to the present invention. The timing extracting device 40 includes switches 41 and 43 and a timing extracting circuit 42. The timing extraction circuit 42 is connected to switches 41 and 43.
Switches 41 and 43 are internally provided with a switch unit (not shown)
And switches the switch in response to a control signal supplied from the outside. Here, when the control signal indicates that the operation of the timing extraction circuit is prohibited, the switches of the switches 41 and 43 are turned off. If the control signal does not indicate that the operation of the timing extraction circuit is prohibited, the switches of the switches 41 and 43 are turned on.

The NRZ signal supplied from the matrix switch unit 30 is sent to a timing extraction circuit 42 via a switch 41. The timing extracting circuit 42 has a timing differentiating circuit 421, a SAW filter 422, and a sine wave / rectangular wave converting circuit 423. Differentiating circuit 42
1 is connected to a SAW filter 422, and the SAW filter 422 is further connected to a sine wave / square wave conversion circuit 423.

The differentiating circuit 421 detects the rising / falling timing of the NRZ signal supplied from the matrix switch section 30 and outputs the detected timing as a discontinuous clock signal. The discontinuous clock signal output from the differentiating circuit 421 is supplied to the SAW filter 422
Supplied to The SAW filter 422 includes a differentiator 42
1. Convert the discontinuous clock signal supplied from 1 into a continuous sine wave signal. Further, this sine wave signal is supplied to a sine wave / square wave conversion circuit 423 in order to obtain a reproduced clock signal of a logic level. The sine wave signal supplied from the SAW filter 422 is
At 3 the signal is converted to a rectangular wave signal. This rectangular wave signal is output as a reproduced clock signal via the switch 43.

As described above, the timing extraction circuit 42
When the control signal indicating the prohibition of the operation is supplied from outside, the switch 41 operates so that the unnecessary NRZ signal is not applied to the SAW filter 422, and the switch 43 does not output the unnecessary reproduced clock signal. Works.

FIG. 3 shows the SAW filter 422 in FIG.
FIG. 6 is a diagram showing resonance characteristics of the present invention. Here, two signals, a DS3 signal and an STS-1 signal, are used as input signals. Accordingly, resonance points are provided at f1 and f2 to support two different transmission speeds. Note that f1 is 44.736 MHz for DS3 signal, and f2 is STS
51.8 MHz for the -1 signal is set.

[0017]

As described above, according to the present invention, SAW
By giving the filter multiple resonance characteristics,
There is an effect that a single timing extraction circuit can cope with a plurality of different transmission speeds. For this reason, it is possible to keep the cost of parts and the adjustment time of the timing extracting device low.

In addition, DS3 signal cross-connect, S
Since the cross connection of the STS-1 signal in ONET can be performed using the same clock extraction circuit,
This has the effect of reducing the scale of the system and reducing power consumption.

[Brief description of the drawings]

FIG. 1 is a basic block diagram for explaining a configuration of a timing extraction device according to the present invention.

FIG. 2 is a conceptual diagram showing a cross connect system to which the present invention can be applied.

FIG. 3 is a diagram showing typical resonance characteristics of a timing extraction filter according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Input terminal 20 Interface reception part 30 Matrix switch part 40 Timing extraction device 41 Switch 42 Timing extraction circuit 421 Differentiation circuit 422 SAW filter 423 Sine wave / square wave conversion circuit 43 Switch 50 Interface transmission part

Claims (3)

(57) [Claims] 1. An input signal according to a type of the signal.
Interface for converting into a first NRZ signal of speed and outputting
And a cross-connect between the first NRZ signal and a second
A matrix switch unit that outputs an NRZ signal; a timing extraction device that receives the second NRZ signal, extracts a clock timing from the second NRZ signal, and outputs the extracted clock timing as a reproduced clock signal And the second NRZ signal is recovered using the recovered clock.
Der cross-connect device, characterized in that it includes a an interface transmitting unit for inversely converting and outputting the signals of
Thus, the timing extraction device converts the second NRZ signal into a discontinuous clock signal, a signal conversion unit; a filter unit that converts the discontinuous clock signal into a continuous sine wave; Means for converting a sine wave into the recovered clock signal, wherein the filter means comprises one SAW filter having a plurality of resonance characteristics corresponding to each of the plurality of different transmission speeds. And a cross-connect device. 2. An input signal according to a type of the signal.
Interface for converting into a first NRZ signal of speed and outputting
And a cross-connect between the first NRZ signal and a second
A matrix switch unit that outputs an NRZ signal; a timing extraction circuit that receives the second NRZ signal, extracts a clock timing from the second NRZ signal, and outputs the extracted clock timing as a reproduced clock signal a timing extraction device equipped with, the second NRZ signal, based on using the reproduction clock
Der cross-connect device, characterized in that it includes a an interface transmitting unit for inversely converting and outputting the signals of
Thus, the timing extraction device responds to the external control signal to generate the second NRZ signal.
First switch means for controlling whether or not to supply a signal to the timing extraction circuit; and outputting the reproduced clock signal extracted by the timing extraction circuit in response to the external control signal. Signal switching means for converting the second NRZ signal into a discontinuous clock signal, and the discontinuous clock signal. Filter means for converting a signal into a continuous sine wave, and means for converting the sine wave into the recovered clock signal, wherein the filter means has one SAW having a plurality of resonance characteristics.
A cross-connect device comprising a filter. 3. Only when the external control signal does not indicate the operation inhibition state of the timing extraction circuit,
The first and second switch means are connected to the second NR
3. The apparatus according to claim 2 , wherein a Z signal is supplied to the timing extraction circuit to output the reproduced clock signal.
Cross-connect device.