KR101727228B1 - Apparatus and method for converting analog to digital using direct conversion - Google Patents

Abstract

A first slicer for slicing an input analog signal based on a first reference signal including a DC voltage signal to output a first sliced signal and a second slicer having a voltage level equal to or higher than that of the first reference signal and having a predetermined duty cycle and an n-th slicer for slicing the first sliced signal based on the n-th reference signal to output an n-th sliced signal.

Description

TECHNICAL FIELD [0001] The present invention relates to an analog-to-digital conversion apparatus and method using a direct conversion method,

More particularly, the present invention relates to a technique for converting an analog signal into a digital signal through at least one or more slicing steps to generate a signal for optical transmission, To an analog-to-digital conversion apparatus and method using a direct conversion method.

As the 5G service enters, the transmission capacity of mobile communication data requires a large capacity, and a large-capacity transmission device is also required. For example, when a building is provided with WCDMA or LTE with a plurality of bands, a mobile communication company installs and operates each optical transmission device and optical line.

A conventional optical transmission apparatus uses a method of quantizing data by using an analog-digital, digital-analog conversion apparatus, and transmitting the converted digital signal to the optical core using an optical transmission apparatus. In the quantization process, a signal transmitted by such an optical transmission scheme is transmitted 10 times as much as the original transmission band width. The diffusion of such a transmission band has a problem in that a plurality of light cores must be used. In addition, the conventional optical transmission apparatus is complicated in configuration including an analog to digital converter (ADC), a digital to analog converter (DAC), a CPU, an EEPROM, a CLOCK, There is a problem that the delay time due to the parts increases.

KR10-0546469 B1

Accordingly, it is an object of the present invention to provide an analog-to-digital conversion apparatus and method capable of generating digital data by directly converting an analog signal into a digital signal through at least one slicing step .

According to an embodiment of the present invention, an analog-to-digital converter includes an analog-to-digital converter that slices an input analog signal on the basis of a first reference signal including a DC voltage signal to output a first sliced signal, 1 slicer and an n-th slicer for slicing the first sliced signal based on an n-th reference signal having a voltage level equal to or greater than the first reference signal and having a predetermined duty cycle to output an n-th sliced signal do.

In one embodiment of the present invention, a second slicer slicing the first sliced signal on the basis of a second reference signal to output a second sliced signal, a second slicer slicing the second sliced signal on the basis of a third reference signal, And outputting a third sliced signal; and a noise eliminator for removing a noise component included in the output signal of any one of the first, second, third, and n-th slicers, And the n-th slicer slices the third sliced signal on the basis of the n-th reference signal to output the n-th sliced signal.

In one embodiment of the present invention, the second slicer may further output a second negative sliced signal having a phase difference of 180 degrees with the second sliced signal, and the noise eliminator may output the second sliced signal, And a noise detector for detecting a digital noise based on the second negative sliced signal and a noise amplifier for amplifying the digital noise, wherein the noise component of the third sliced signal is amplified using the amplified digital noise, Can be removed.

In one embodiment of the present invention, the second reference signal may be a DC voltage signal having a voltage level equal to or greater than the first reference signal, the third reference signal is greater than the second reference signal, And may be a DC voltage signal having a voltage level lower than the reference signal.

In one embodiment of the present invention, the apparatus may further include a band-pass filter for passing only a signal having a frequency of a pass band among the signals input to the first slicer.

According to another aspect of the present invention, there is provided an analog-to-digital conversion method comprising: outputting a first sliced signal by slicing an input analog signal based on a first reference signal including a DC voltage signal; And slicing the first sliced signal based on an n-th reference signal having a voltage level equal to or higher than the first reference signal and having a predetermined duty cycle to output an n-th sliced signal.

According to an embodiment of the present invention, there is provided a method for generating a second sliced signal, comprising: outputting a second sliced signal by slicing the first sliced signal on the basis of a second reference signal; And outputting a third sliced signal, and removing a noise component included in any one of the first, second, third, and n-th sliced signals, wherein the nth sliced signal Wherein the outputting step slices the third sliced signal on the basis of the n-th reference signal and outputs the n-th sliced signal.

According to an embodiment of the present invention, the method may further include outputting a second negative sliced signal having a phase difference of 180 degrees with the second sliced signal, A step of detecting digital noise based on the sliced signal and the second negative sliced signal, amplifying the digital noise, and removing the noise component of the third sliced signal using the amplified digital noise . ≪ / RTI >

In one embodiment of the present invention, the second reference signal may be a DC voltage signal having a voltage level equal to or greater than the first reference signal, the third reference signal is greater than the second reference signal, And may be a DC voltage signal having a voltage level lower than the reference signal.

In one embodiment of the present invention, the method may further include passing only a signal having a frequency of a passband among the signals input to the first slicer using a band pass filter.

According to such an analog-to-digital conversion apparatus and method, it is possible to simplify the complex circuit implementation of an existing optical transmission apparatus and use a single optical line. Also, the mobile communication service band can be transmitted while maintaining the original bandwidth without spreading in the quantization process. In addition, the delay time in the digital conversion process can be reduced.

1 is a block diagram of an analog-to-digital conversion apparatus according to an embodiment of the present invention.
Figure 2 shows the waveform of the input analog signal.
Figure 3 shows the waveform of the primary sliced signal.
4 shows the waveform of the second sliced signal.
5 shows the waveform of the third sliced signal.
6 shows the waveform of the fourth sliced signal.
7 is a conceptual diagram for explaining a noise removing unit of the analog-to-digital converting apparatus of FIG.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described in more detail with reference to the accompanying drawings.

1 is a block diagram of an analog-to-digital conversion apparatus according to an embodiment of the present invention.

Referring to FIG. 1, the analog-to-digital conversion apparatus may include a preprocessing unit 100, a slicing unit 200, and a noise removing unit 300.

The preprocessing unit 100 may process an analog signal SIG to be converted into a digital signal to generate an input signal SIG_A of the slicing unit 200. [ In one embodiment, the preprocessing unit 100 may comprise a band-stop filter, a band-pass filter.

Hereinafter, the input analog signal SIG_A input to the slicing unit 200 is a signal generated by modulating the WCDMA 1FA (5 MHz) signal and having a center frequency of 70 MHz. However, no.

2 shows waveforms of the input analog signal SIG_A. The input analog signal SIG_A described above is shown in FIG. 2 (a), and FIG. 2 (b) And shows the waveform measured by extending.

Referring again to FIG. 1, the preprocessing unit 100 may pass only a frequency band signal to be input to the slicing unit 200 using a band-stop filter and a band-pass filter. For example, the bandpass filter may be a balanced bandpass filter.

The preprocessing unit 100 may further include a phase shifter. The phase shifter may generate an input analog signal SIG_A 'having a phase difference of 180 degrees from the input analog signal SIG_A. The first slicer 210 may receive the input analog signal SIG_A. The first slicer 210 may further receive the analog signal SIG_A 'generated by the phase shifter.

The slicing unit 200 may include at least one slicer that slices the input analog signal SIG_A. The slicing is performed by comparing the input signal with a reference signal having a constant voltage level. When the input signal is greater than or equal to the reference signal, the signal has a HIGH level. When the input signal is smaller than the reference signal, Quot; LOW " level. For example, the high level may be 1 V and the low level may be 0 V. [

In one embodiment, the slicer 200 may include a first slicer 210, a second slicer 220, a third slicer 230, and a fourth slicer 240.

The first slicer 210 may output the first sliced signal SIG1 by slicing the input analog signal SIG_A based on the first reference signal. The first slicer 210 may further output a first negative sliced signal SIG1 'having a phase difference of 180 degrees from the first sliced signal SIG1.

In one embodiment, the first slicer 210 slices the input analog signal SIG_A on the basis of the first reference signal to generate a first sliced signal SIG1, and generates the first sliced signal SIG1, To generate a first negative sliced signal SIG1 '.

The first reference signal may be a DC voltage signal having a first voltage level. The first sliced signal SIG1 has a first high level in an interval where the input analog signal SIG_A is greater than or equal to the first reference signal and a low level in a section in which the input analog signal SIG_A is less than the first reference signal Lt; / RTI >

The waveform of the signal sliced by the first slicer 210 (hereinafter referred to as first sliced) is shown in FIG. Comparing the waveform of the primary sliced signal shown in FIG. 3 with the waveform of the input analog signal SIG_A shown in FIG. 2, it can be seen that the signal is distorted at the peak of the primary sliced signal. The first sliced signal includes a large amount of analog signal components, and noise due to the first reference signal may be mixed.

Referring again to FIG. 1, the second slicer 220 may output the second sliced signal SIG2 by slicing the first sliced signal SIG1 based on the second reference signal. The second slicer 220 may further output a second negative sliced signal SIG2 'having a phase difference of 180 degrees from the second sliced signal SIG2.

In one embodiment, the second slicer 220 slices the first sliced signal SIG1 based on the second reference signal to generate a second sliced signal SIG2, The second negative sliced signal SIG2 'may be inverted to generate the second negative sliced signal SIG2'. In another embodiment, the second slicer 220 generates the second sliced signal SIG2 by slicing the first sliced signal SIG1 based on the second reference signal, and generates the second sliced signal SIG2 based on the second reference signal 1 negative sliced signal SIG1 'to generate a second negative sliced signal SIG2'. The second negative sliced signal SIG2 'may be 180 degrees out of phase with the second sliced signal SIG2.

The second reference signal may be a DC voltage signal having a second voltage level. The second voltage level of the second reference signal may be greater than or equal to the first voltage level of the first reference signal. The second sliced signal SIG2 has a second high level in a section where the first sliced signal SIG1 is equal to or greater than the second reference signal and the first sliced signal SIG1 is smaller than the second reference signal And may have a low level in the interval. The second high level may be greater than the first high level of the first sliced signal SIG1.

The waveform of the signal sliced (hereinafter referred to as second sliced) by the second slicer 220 is shown in FIG. The secondary slicing may be a step of shaping the signal using the same or a larger reference signal as compared with the primary slicing by the first slicer 210. [ The shaping of such a signal may be a step that minimizes jitter, over-signal distortion, and under-signal distortion that may occur in a high-speed digital signal.

Referring again to FIG. 1, the third slicer 230 may output the third sliced signal SIG3 by slicing the second sliced signal SIG2 based on the third reference signal. The third slicer 230 may further output a third negative sliced signal SIG3 'having a phase difference of 180 degrees from the third sliced signal SIG3.

In one embodiment, the third slicer 230 slices the second sliced signal SIG2 based on the third reference signal to generate a third sliced signal SIG3, The third negative sliced signal SIG3 'may be inverted to generate the third negative sliced signal SIG3'. In another embodiment, the third slicer 230 generates the third sliced signal SIG3 by slicing the second sliced signal SIG2 based on the third reference signal, 2 negative sliced signal SIG2 'to generate a third negative sliced signal SIG3'. The third negative sliced signal SIG3 'may have a phase difference of 180 degrees from the third sliced signal SIG3.

The third reference signal may be a DC voltage signal having a third voltage level. The third voltage level of the third reference signal may be greater than the second voltage level of the second reference signal. The third sliced signal SIG3 has a third high level in a section where the second sliced signal SIG2 is equal to or greater than the third reference signal and the second sliced signal SIG2 is smaller in level than the third reference signal And may have a low level in the interval. The third high level may be greater than the second high level of the second sliced signal SIG2.

The waveform of the signal sliced by the third slicer 230 (hereinafter referred to as tertiary slicing) is shown in Fig. Compared with the first sliced signal shown in FIG. 3, the third sliced signal shown in FIG. 5 can be confirmed that the quality of the waveform is completely different. The tertiary slicing may be a step for implementing a signal that minimizes loss of original data, for example. The tertiary slicing can be adjusted when interfaced with the digital-to-analog conversion at a later stage, which can be important for the correction of EVM (Error Vector Magnitude).

Referring again to FIG. 1, the fourth slicer 240 may slice the third sliced signal SIG3 based on the fourth reference signal to output the fourth sliced signal SIG4. The fourth slicer 240 may further output a fourth negative sliced signal SIG4 'having a phase difference of 180 degrees from the fourth sliced signal SIG4.

In one embodiment, the fourth slicer 240 slices the third sliced signal SIG3 based on the fourth reference signal to generate a fourth sliced signal SIG4, SIG4) to generate a fourth negative sliced signal SIG4 '. In another embodiment, the fourth slicer 240 generates the fourth sliced signal SIG4 by slicing the third sliced signal SIG3 on the basis of the fourth reference signal, 3 negative sliced signal SIG3 'to generate a fourth negative sliced signal SIG4'. The fourth negative sliced signal SIG4 'may be 180 degrees out of phase with the fourth sliced signal SIG4.

Slicing by the fourth slicer 240 (hereinafter referred to as fourth slicing) may be a step for transforming the output signal of the third slicer 230 into a digital signal for final optical transmission. The waveform of the fourth sliced and digitally converted signal is shown in FIG.

In order to transform the output signal of the third slicer 230 into a digital signal for final optical transmission, the fourth reference signal may be a signal having a predetermined duty cycle. For example, the fourth reference signal may have a 50% duty cycle, but is not limited thereto.

The fourth voltage level of the fourth reference signal may be greater than the third voltage level of the third reference signal. Alternatively, the fourth reference signal may be a modulated signal such that the third reference signal has a duty cycle of 50%.

The fourth sliced signal SIG4 has the fourth high level in the section where the third sliced signal SIG3 is equal to or larger than the fourth reference signal and the third sliced signal SIG3 is smaller than the fourth reference signal And may have a low level in the interval. The fourth high level may be greater than the third high level of the third sliced signal SIG3.

The values of the first to fourth high levels of each of the first to fourth sliced signals SIG1, SIG2, SIG3, and SIG4 may be determined to be predetermined values. In one embodiment, the second high level may be greater than the first high level, the third high level may be greater than the second high level, and the fourth high level may be greater than the third high level. For example, the first high level may be 1.1 V, the second high level may be 1.2 V, the third high level may be 1.3 V, and the fourth high level may be 1.4 V, but is not limited thereto.

The first to fourth voltage levels of the first to fourth reference signals used for each slicing can be determined by analyzing the data value of the signal obtained by dividing the highest point level and the lowest point level of the input analog signal SIG_A in four stages have.

For example, the first voltage level may be included between the highest and lowest levels of the input analog signal SIG_A. The second voltage level may be included between the highest point level and the lowest point level of the first sliced signal SIG1 and the second voltage level may be greater than or equal to the first voltage level. The third voltage level may be included between the highest point level and the lowest point level of the second sliced signal SIG2, and the third voltage level may be greater than the second voltage level. The fourth voltage level may be included between the highest point level and the lowest point level of the third sliced signal SIG3 and the fourth voltage level may be greater than or equal to the third voltage level.

A step of removing a noise component contained in the signal may be performed to remove the noise before sending out the digital signal. For example, noise components included in output signals of any one of the first, second, third and fourth slicers 210, 220, 230, and 240 may be removed.

FIG. 1 illustrates an embodiment in which the noise component included in the output signal of the third slicer 230 is removed before the fourth slicer 240 performs the fourth slicer. However, the present invention is not limited thereto. In another embodiment, the noise remover 300 may be disposed at the output of at least one of the first to fourth slicers 210, 220, 230, and 240. The noise removing unit 300 will be described in detail below with reference to FIG.

7 is a conceptual diagram for explaining a noise removing unit 300 of the analog-to-digital converting apparatus of FIG. 1 and 7, the noise eliminator 300 removes noise components included in output signals of any one of the first, second, third, and fourth slicers 210, 220, 230, can do. The noise removing unit 300 may include a noise detecting unit 310, a noise amplifying unit 320, a first noise removing unit 330, and a second noise removing unit 340.

Hereinafter, the case where noise is removed prior to the last slicing step (i.e., the fourth slicing by the fourth slicer 240) using the output signal of the second slicer 220 will be described.

In one embodiment, the noise detector 310 may be disposed between the second slicer 220 and the third slicer 230. The noise detector 310 can detect digital noise based on the second sliced signal SIG2 and the second negative sliced signal SIG2 '. For example, the noise detector 310 may cancel the signal components using the second sliced signal SIG2 and the second sliced signal SIG2 'in the mutually-phase-inverted relationship, Can be detected. The noise amplification unit 320 can amplify the digital noise detected by the noise detection unit 310.

In one embodiment, the first noise remover 330 may remove noise from the third sliced signal SIG3 and the third negative sliced signal SIG3 'using the amplified digital noise. For example, the first noise eliminator 330 uses the amplified digital noise to generate a third sliced signal SIG3 and a third negative slice signal SIG3, which are transmitted from the third slicer 230 to the fourth slicer 240, The noise of the sliced signal SIG3 'can be removed.

The above description of the noise detector 310, the noise amplifier 320, the first noise remover 330 and the second noise remover 340 is for describing one embodiment, But is not limited thereto. In other embodiments, the noise detector 310 may detect the digital noise using one or more outputs of the first through fourth slicers 210, 220, 230, and 240, and may detect the digital noise using the detected digital noise Noise can be removed from any one or more of the first to fourth slicers 210, 220, 230, and 240.

The fourth sliced signal SIG4 and / or the fourth negative sliced signal SIG4 'may be outputted as a digitally converted signal of the input analog signal SIG_A from the analog-digital conversion device. The fourth sliced signal SIG4 and / or the fourth negative sliced signal SIG4 'may be optically transmitted using an optical cable as a digital signal for optical transmission. The fourth sliced signal SIG4 and the fourth negative sliced signal SIG4 'may be transmitted as a transmission line using an optical cable, a UTP cable, or a coaxial cable.

The analog-to-digital conversion apparatus according to the present invention can minimize the delay time in the digital conversion to 10 ns or less by converting an analog signal directly into a digital signal using at least one slicer, The synchronization loss can be minimized. Therefore, high-speed data transmission is possible in the LTE or WCDMA transmission scheme.

While the invention has been shown and described with reference to certain embodiments thereof, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined by the appended claims. However, it should be understood that such modifications are within the technical scope of the present invention. Accordingly, the true scope of the present invention should be determined by the technical idea of the appended claims.

100: preprocessing unit 200:
210: first slicer 220: second slicer
230: third slicer 240: fourth slicer
300: Noise removing unit 310: Noise detecting unit
320: noise amplification unit 330: first noise rejection unit
340: second noise rejection

Claims (10)

A first slice signal is generated by slicing an input analog signal based on a first reference signal including a DC voltage signal to output the first sliced signal and a first negative slice having a phase difference of 180 degrees with the generated first sliced signal, A first slicer for outputting a de-signal;
(N is a natural number of at least two sequential signals such as 2, 3, 4, 5, ...) having a voltage level equal to or higher than the first reference signal and a predetermined duty cycle, An n-th slicer for generating an n-th sliced signal by slicing the first sliced signal and outputting the n-th sliced signal and outputting an n-th negative sliced signal having a phase difference of 180 degrees with the generated n-th sliced signal; And
1 sliced signal and the (m-1) th negative slice when the m-th sliced signal and the m-th sliced signal are arranged at output ends of any one of the first slicer and the n-th slicer, And a noise removing unit for removing noise of the m-th sliced signal and the m-th negative sliced signal after the digital noise is detected and amplified using the signal. delete delete delete delete A method for analog-to-digital conversion using the analog-to-digital converter according to claim 1, comprising: generating an analog signal by slicing a first reference signal including a DC voltage signal to generate and output a first sliced signal; Outputting a first negative sliced signal having a phase difference of 180 degrees with the generated first sliced signal;
(N is a natural number of at least two sequential signals such as 2, 3, 4, 5, ...) having a voltage level equal to or higher than the first reference signal and a predetermined duty cycle, Generating an n-th sliced signal by slicing the first sliced signal and outputting the n-th sliced signal, and outputting an n-th negative sliced signal having a 180-degree phase difference with the n-th sliced signal; And
(M is a natural number equal to or greater than 2) slicers when the noise eliminating means is disposed at the output end of any one of the first slicer, the second slicer, and the n-th slicer, And removing the noise of the m-th sliced signal and the m-th negative sliced signal after detecting and amplifying the digital noise using the (m-1) th negative sliced signal and the m-th negative sliced signal. Conversion method.
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