Wireless communication device and operating method thereof

Wireless communication device and method of operation thereof

The present invention relates to a wireless communication device, and more particularly, to a wireless communication device performing an NFC function.

In general, near field communication (NFC) is performed between the card and the reader. Such a card may be embedded in, for example, a mobile device, such as a smart phone, for contactless electronic payments.

The NFC protocol is a field of existing radio frequency identification (RFID), and may operate a terminal having a tag embedded therein in an active mode. As a result, it is possible to perform not only a function as a tag, but also a function of a reader reading a tag, a writer inputting information into the tag, and a P2P function between terminals.

NFC protocol is specified as a standard in ISO 18092, and in addition to the frequency of 13.56 MHz, short-range wireless communication can be performed with various frequency signals including 125 kHz, 135 kHz and 900 MHz. The NFC protocol may support readers such as ISO 14443 TYPEA (Mifare), TYPEB, TYPEF (Felica), and ISO 15693 TYPEV, and cards such as TYPEA, TYPEB, TYPEF and TYPEV.

Under various NFC protocols, transmission data is transmitted through a transmission channel after source coded by a predetermined coding method, and a receiver of a reader or card receives various types of transmission signals as reception data. For example, in the case of a card of ISO 14443 TYPEA, a Miller coding signal is received as reception data. In addition, in the case of a TYPEA reader, a sub-carrier load-modulated signal is received at a sub-carrier frequency after Manchester coding or BSPK coding is performed. Also, in the case of a TYPEB card, an NRZ coded signal is received, and in the case of a TYPEB reader, a BPSK coded and then subcarrier load modulated signal is received at the subcarrier frequency. And, in the case of the reader of ISO 15693, a sub-carrier load-modulated signal is received at a sub-carrier frequency after Miller coded. The communication speed of the received data has a distribution range of 26 kbps to 847 kbps.

In the case of a reader supporting various NFC protocols, since they transmit and receive signals of various frequencies, it is important to adaptively remove noise according to the communication frequency. This is because, when noise is removed by uniformly determining the level of mask information, not only noise but also damping components included in radio signals may not be properly filtered, and normal signals that should not be filtered may also be filtered. Moreover, since the damping component increases according to the size of the signal, there is a limitation in increasing the communication distance. Accordingly, improving the performance of a wireless communication device (eg, an NFC reader, or a smart phone including the same) by filtering noise and damping components is emerging as an important problem.

<p>An object of the present invention is to provide an NFC reader of improved performance, or a wireless communication device including the same.</p>

<p>According to an embodiment of the present invention, a calibrator for processing an output signal of an analog-to-digital converter in a wireless communication device includes: a level filter that removes noise from an output signal of the analog-to-digital converter using mask information defining a signal level ; a timing filter that removes pulses out of a reference duty ratio from the level-filtered signal using timing information; a pattern filter for removing pulses determined not to be continuous as many as a reference number from the timing-filtered signal using pattern information; and a duty correction circuit for correcting the duty of the pattern-filtered signal.</p><p>In an embodiment, the apparatus may further include a noise detector configured to generate the mask information using upper trigger point (UTP) and lower trigger point (LTP) information obtained by sampling the output signal of the analog-to-digital converter.</p><p>As another embodiment, the level filter processes the output signal of the analog-to-digital converter using the mask information and outputs a 1-bit signal, but the processing by the level filter may be based on a hysteresis-comparison operation.</p><p>As another embodiment, the timing information may be determined by a ratio of logic high and logic low included in logic data obtained by sampling the 1-bit signal with a reference frequency.</p><p>As another embodiment, the timing filter may remove a signal for one period of the logic data when the ratio of the logic high for one period of the logic data is out of a reference range.</p><p>As another embodiment, the pattern filter is continuous by the reference number with reference to the number of times the timing-filtered interval between rising edges of two adjacent pulses of the 1-bit signal is counted by the clock having the reference frequency. It is possible to remove the pulses determined not to do so.</p><p>As another embodiment, when the counted number is out of the reference number, the two adjacent pulses may be determined to be discontinuous.</p><p>As another embodiment, the pattern information may be determined according to a protocol defining a signal transmitted and received by the wireless communication device.</p><p>As another embodiment, the level filter output terminal, the timing filter output terminal, the pattern filter output terminal, and connected to the duty correction circuit output terminal, the level-filtered signal, the timing-filtered signal, the The pattern-filtered signal and the duty-corrected signal may further include a multiplexer to select and output.</p><p>As another embodiment, the analog-to-digital converter may be provided in the calibrator.</p><p>A method of operating a wireless communication device according to an embodiment of the present invention includes: filtering the level of the coded signal using mask information generated by sampling noise of a coded signal by an analog-to-digital converter; removing pulses out of a reference duty ratio from the level-filtered signal using timing information; removing pulses determined to be not continuous as many as the reference number from the signal from which pulses that are out of the reference duty ratio are removed using pattern information; and correcting the duty of the signal from which pulses determined not to be continuous as many as the reference number are removed.</p><p>As an embodiment, the mask information may be generated through upper trigger point (UTP) and lower trigger point (LTP) information of noise of the coded signal.</p><p>As another embodiment, the step of filtering the level of the coded signal includes: performing a hysteresis-comparison operation using the output signal of the analog-to-digital converter and the UTP and LTP information and outputting a 1-bit signal may include</p><p>As another embodiment, the step of removing the pulses deviating from the reference duty ratio may include a logic high and a logic low included in logic data obtained by sampling the level-filtered signal with a reference frequency. It can be implemented with reference to the ratio of</p><p>As another embodiment, the step of removing the pulses determined not to be continuous as many as the reference number may include a section between rising edges of two adjacent pulses included in a signal from which pulses out of the reference duty ratio are removed, the reference It can be executed by referring to the number of times counted by a clock having a frequency.</p>

<p>According to an embodiment of the present invention, by performing a filtering operation by separating noise and damping components included in a normal signal, the performance of an NFC reader or a wireless communication device including the same can be improved.</p>

1A and 1B are block diagrams illustrating a wireless communication device according to an embodiment of the present invention. 2 is a block diagram showing a configuration example of a receiver included in a wireless communication device according to an embodiment of the present invention. 3A and 3B are block diagrams illustrating a calibrator of a wireless communication device according to an embodiment of the present invention. 4 is a block diagram showing an exemplary configuration of a level/timing filter of the calibrator shown in FIG. 3B. 5 is a waveform showing noise in a noise detection section located at the beginning of a radio signal. 6A and 6B are diagrams illustrating a filtering method in a level filter. 7A and 7B are diagrams illustrating a method of removing noise included in a level-filtered signal using predetermined timing information. 8A to 8C are diagrams illustrating a method of removing noise included in a timing-filtered signal using predetermined pattern information. 9 is a diagram illustrating a process of correcting the duty of a pattern-filtered signal. 10 is a flowchart illustrating filtering operations of a wireless communication device according to an embodiment of the present invention. 11 is a flowchart illustrating an exemplary operation of the timing-filtering operation shown in FIG. 10 . 12 is a flowchart illustrating an exemplary operation of the pattern-filtering operation shown in FIG. 10 . 13 is a block diagram illustrating a portable terminal to which a wireless communication device according to an embodiment of the present invention is applied.

It is to be understood that both the foregoing general description and the following detailed description are exemplary, and it is to be considered that an additional description of the claimed invention is provided. Reference signs are indicated in detail to preferred embodiments of the present invention, examples of which are indicated in the reference drawings. Wherever possible, the same reference numbers are used in the description and drawings to refer to the same or like parts.

In the following, a wireless communication apparatus and an operating method thereof are used as an example for describing the features and functions of the present invention. However, one skilled in the art will readily appreciate other advantages and capabilities of the present invention in accordance with the teachings herein. The present invention may also be implemented or applied through other embodiments. Moreover, the detailed description may be modified or changed according to the viewpoint and use without departing significantly from the scope, spirit and other objects of the present invention.

Although the terms "first", "second", etc. may be used herein to describe various elements, these elements are not limited by these terms. These terms may only be used to distinguish one component from others. As used in the present description, terms such as "comprising" or "consisting of" specify the presence of the described feature, step, operation, component, and/or component, but with one or more additional features, steps, and/or steps being described. , enabling the existence of an action, component, component, and/or group thereof. In the description of the embodiment, in the case where it is described as being formed "on/under" of each layer, the above (top)/bottom (bottom) is directly (directly) or those formed indirectly through other layers. When an element or layer is referred to as being "connected", "coupled to," or "adjacent to" another element or layer, it may be directly connected to, coupled to, or adjacent to the other element or layer; Alternatively, it will be appreciated that there may be elements or layers sandwiched therebetween.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings so that those of ordinary skill in the art to which the present invention pertains can easily implement the technical idea of the present invention.

1A and 1B are block diagrams illustrating a wireless communication device according to an embodiment of the present invention. 2 is a block diagram showing a configuration example of a receiver included in a wireless communication device according to an embodiment of the present invention.

Referring to FIG. 1A , a wireless communication device may have a Near Field Communication (NFC) function. The wireless communication device may include an antenna, a receiver 100 , an analog to digital converter (ADC) 200 , a calibrator 300 , and a modem 400 .

Referring to FIG. 2 together with FIG. 1A, the receiver 100 includes a mixer 110, a low pass filter (LPF) 120 and 120', and Variable Gain Amplifiers (VGAs) 130 and 130' may be included.

The mixer 110 serves to remove a carrier wave from the received signal. The mixer 100 may be provided with one or a pair, and may generate an I-channel signal and a Q-channel signal. Here, the I-channel signal is an in-phase channel signal, and the Q-channel signal is a quadrature channel signal, and has a phase difference of 90 degrees from each other. The low-pass filters 120 and 120 serve to remove noise included in a pair of signals processed by the mixer 110 . The variable gain amplifiers 130 and 130' serve to amplify a signal weakened while being transmitted through the air. In addition, the low-pass filters 120 and 120' and the variable gain amplifiers 130 and 130' may be provided in pairs to process the I-channel signal and the Q-channel signal, respectively.

The analog-to-digital converter 200 converts the signals (I_CH Rx OUT and Q_CH Rx OUT) output from the receiver 100 into a digital signal (eg, ADC_DATA in FIG. 3 ) and transmits it to the calibrator 300 . . For example, the analog-to-digital converter 200 may be a 4-bit converter.

The calibrator 300 may remove noise and damping components included in the digitally-converted I-channel signal and the Q-channel signal. A pair of calibrators 300 may be provided to process an I-channel signal and a Q-channel signal, respectively. The calibrator 300 may include a noise detector 310 and a plurality of filters to remove noise and damping components. The plurality of filters are, as will be described in detail, a filter that removes noise using mask information formed by the noise detector 310, a filter that removes noise using timing information of a mask-filtered signal, and a timing- A filter that removes noise using pattern information of the filtered signal may be included.

Alternatively, as shown in FIG. 1B , a digital calibrator 500 of a wireless communication device according to an embodiment of the present invention is implemented as one IP (intellectual property) including a digital converter 510 . can be

Referring to FIG. 1B , the digital calibrator 500 may include an analog-to-digital converter 510 , a noise detector 520 , and filters. That is, the digital calibrator 500 may be provided as one IP to receive and convert an analog signal and perform a filtering operation. A pair of digital calibrators 500 may be provided to process an I-channel signal and a Q-channel signal, respectively. The digital calibrator 500 is similar to the calibrator 300 shown in FIG. 1A except that it can also perform a digital converting operation. Accordingly, detailed descriptions of overlapping parts will be omitted.

A wireless communication device according to an embodiment of the present invention removes noise included in a wireless signal, and receives continuous pulses as many as the number (eg, 4, 8, or more) specified in the protocol. The removal of the damping component that occurs immediately after is handled separately. For example, the wireless communication device according to an embodiment of the present invention generates mask information using noise sampled in a preamble section, and performs a level-filtering operation of removing noise using the mask information. . In addition, the wireless communication device according to an embodiment of the present invention removes noise or damping components through timing-filtering and pattern-filtering operations. Finally, the wireless communication device according to an embodiment of the present invention corrects the duty of the filtered signals. As a result, it is possible to solve problems such as shortening of a communication distance of an NFC reader, or a wireless communication device including the same, caused by a conventional processing method that simultaneously removes noise and damping components.

3A and 3B are block diagrams illustrating a calibrator of a wireless communication device according to an embodiment of the present invention. 4 is a block diagram showing an exemplary configuration of a level/timing filter of the digital calibrator shown in FIG. 3B. The digital calibrator 500 of FIG. 3B has the same function as the calibrator 300 of 3A except that it can perform a digital converting operation. Hereinafter, it will be described with reference to FIG. 3B as an example.

Referring to FIG. 3B , the digital calibrator 500 includes an analog-to-digital converter 510 , a noise detector 520 , a level/timing filter 530 , a pattern filter 540 , and a duty correction circuit 550 . can do. The filtering operations performed in the digital calibrator 500 will be briefly described as follows.

The analog-to-digital converter 510 may convert the analog signal Rx_OUT received from the receiver (see FIG. 1B , 100 ) into a digital signal. For example, the analog-to-digital converter 510 may be a 4-bit converter.

The noise detector 520 receives the digital-converted signal ADC_DATA from the analog-to-digital converter 510 . The noise detector 520 may generate mask information for removing noise by sampling noise included in the digital-converted signal ADC_DATA. In this case, the sampling operation may be performed by the main clock CLK. In addition, the noise detector 520 may transmit the generated mask information information REFA and REFB to the level/timing filter 530 .

The level/timing filter 530 may remove noise from the signal ADC_DATA received from the analog-to-digital converter 510 by using the information REFA and REFB of the received mask information. For example, the level/timing filter 530 may include a level filter 532 and a timing filter 534 . The level filter 532 may remove noise of the signal ADC_DATA received from the analog-to-digital converter 510 by using the mask information. The timing filter 534 may perform an operation of removing noise from the mask-filtered signal LF_OUT by using predetermined timing information. A filtering operation for removing noise using predetermined timing information will be described in detail with reference to FIG. 7 .

The pattern filter 540 may receive the timing-filtered signal LF_TF_OUT and remove noise from the timing-filtered signal LF_TF_OUT by using predetermined pattern information. The predetermined pattern information may be determined based on a characteristic or protocol of a signal received through an antenna. For example, assume the case of an NFC reader (Near Field Communication reader) that transmits and receives radio waves using a TYPEA signal. If 4, 8, or more continuous pulses, which are the number of times specified in the protocol, are input, it will be determined as a normal signal. If not, it is determined as noise and an operation to remove it will be performed. A digital signal such as "1010110..." is restored by combining 4 consecutive pulses, 8 consecutive pulses, or more consecutive pulses. And, the number of times the interval between each pulse is counted by the internal clock CLK_INT must be within a predetermined number (eg, 20 times) to be recognized as a normal signal. The internal clock CLK_INT may be selected by the selection clock circuit 350 based on the main clock CLK. The frequency of the internal clock CLK_INT may be the same as or different from that of the main clock CLK depending on the type of signal transmitted and received by the wireless communication device.

The duty correction circuit 550 may receive the pattern-filtered signal LF_TF_PF_OUT to correct the duty. Even if the filtering processes in the previous filters are performed, since the filtering operation is performed with a certain margin, the duty of the pattern-filtered signal LF_TF_PF_OUT may not be exactly 50%. Therefore, the operation of finally correcting the duty is performed.

In addition to this, the digital calibrator 500 may further include a selection clock circuit 560 , a reset control circuit 570 , and a multiplexer (MUX) 580 .

The selection clock circuit 560 may receive a signal SEL_DR controlling to select a mode in which the wireless communication device operates to determine an internal clock CLK_INT in which the wireless communication device operates. For example, if the wireless communication device according to an embodiment of the present invention transmits and receives a TYPEA signal having a frequency of 848 kHz, the internal clock CLK_INT selected by the selection clock circuit 560 may be 13.56 MHz. Alternatively, if the ISO 15693 signal is transmitted and received, the internal clock CLK_INT selected by the selection clock circuit 560 may be 6.78 MHz. That is, the internal clock CLK_INT may be selected by the selection clock circuit 560 according to a signal transmitted and received by the wireless communication device.

The reset control circuit 570 may receive the reset signal RST and the reference set signal REF_SET to reset the level/timing filter 530 , the pattern filter 540 , and the duty correction circuit 550 .

The multiplexer (MUX) 580 may receive a level-filtered signal LF_OUT, a timing-filtered signal LF_TF_OUT, a pattern-filtered signal LF_TF_PF_OUT, and a duty-corrected signal LF_TF_PF_DC_OUT. In addition, in response to the output selection signal OUTPUT_SEL, a necessary signal may be selected from among these received signals and output as an output signal SIGNAL_OUT. For example, when the pattern-filtered signal LF_TF_PF_OUT satisfies the reference quality, the multiplexer 580 selects and outputs the pattern-filtered signal LF_TF_PF_OUT without correction by the duty correction circuit 550 . . The same is true for the level-filtered signal LF_OUT and the timing-filtered signal LF_TF_OUT. By doing so, unnecessary power consumption can be reduced.

A wireless communication device according to an embodiment of the present invention removes noise included in a wireless signal, and receives continuous pulses as many as the number (eg, 4, 8, or more) specified in the protocol. The removal of the damping component that occurs immediately after is handled separately. As a result, it is possible to solve problems such as shortening of a communication distance of an NFC reader, or a wireless communication device including the same, caused by a conventional processing method that simultaneously removes noise and damping components.

5 is a waveform showing noise in a noise detection section located at the beginning of a radio signal. The waveform shown in FIG. 5 is a digital signal as a signal (ADC_DATA) input to the noise detector (refer to FIG. 3b, 520) through the analog-to-digital converter (see FIG. 3b, 510), but it is expressed as rough for convenience .

Referring to FIG. 5 together with FIG. 3B , the operation of the noise detector 520 will be described as follows.

The noise detector 510 may detect noise included in the digital-converted signal ADC_DATA and form mask information for removing the noise. In general, when performing wireless communication, only noise is detected in a preamble section immediately before a normal signal including communication information is received. The noise detector 520 detects the highest level (Upper Trigger Point) and the lowest level (Lower Trigger Point; LTP) of noise in the preamble period, that is, the noise detection period, and information (M_REFA and M_REFB) is transferred to the level timing filter 530 . A sampling operation for detecting UTP and LTP of noise may be performed by the main clock CLK. This is to filter all the signals between the UTP and LTP of the signal in the noise detection section so that noise included in the normal signal can be primarily removed. The UTP and LTP information REFA and REFB of the noise detected by the noise detector 520 is transmitted to the level/timing filter 530 .

If there is a need to mainly remove a damping component because the level of noise included in the signal is too small, the noise detector 520 uses the basically set UPT and LTP information (M_REFA and M_REFB) to provide mask information. information can be created. In this case, the M_REFA and M_REFB signals will be transferred to the level/timing filter 530 as it is. The basically set UPT and LTP information (M_REFA and M_REFB) may be received from the outside of the calibrator (eg, a modem or an application processor).

6A and 6B are diagrams illustrating a filtering method in a level filter. The waveforms shown in FIGS. 6A and 6B are "digital" signals (ADC_DATA) output from the analog-to-digital converter, but are shown to be rough for convenience. For example, the signal ADC_DATA may be a signal output from a 4-bit analog-to-digital converter.

The level filter (see FIG. 4B , 532 ) filters noise included in the signal ADC_DATA received from the analog-to-digital converter 510 using the filter mask information REFA and REFB received from the noise detector 520 . can As described above, REFA and REFB may include information on UTP and LTP in the noise detection section, respectively. That is, a signal existing between UTP and LTP is considered as noise and filtered.

In addition, the level filter (refer to FIG. 4B , 532 ) may generate a 1-bit output signal LF_OUT. For example, the level filter may perform the following hysteresis-compare operation. A section from the intersection of the rising curve of ADC_DATA and UPT to the intersection of the falling curve of ADC_DATA and LTP may be recognized as a digital signal "1". On the other hand, a section from the intersection of the falling curve of ADC_DATA and LTP to the intersection of the rising curve of ADC_DATA and UPT may be recognized as a digital signal "0". That is, a 1-bit digital signal is output as the ADC_DATA signal level-filtered by the mask information.

In the case of the filtering operation in the level filter 532, the damping component may be removed as shown in FIG. 6A, but as shown in FIG. 6B, the damping component is out of the range of UTP and LTP of the mask information and is normal. It may be recognized as a signal. As described above, when the damping component is recognized as a normal signal, the damping component and noise may be removed by the timing-filtering operation.

7A and 7B are diagrams illustrating a method of removing noise included in the level-filtered signal LF_OUT using predetermined timing information.

Even if the level-filtering operation is performed on the output ADC_OUT from the analog digital signal, the damping component or noise may not be removed. This is because the size of the damping component may be out of the range of the mask information, or noise mixed in a section other than the preamble section may be out of the range of the mask information.

For example, suppose that a wireless communication device including an NFC reader according to an embodiment of the present invention transmits and receives a TYPEA signal having a frequency of 848 kHz. In this case, the level-filtered signal LF_OUT may be counted by the internal clock CLK_INT having a frequency of 13.56 MHz. In addition, it may be determined whether the signal is a normal signal by referring to a ratio of a logic high and a logic low included in one clock of the level-filtered signal LF_OUT. If 13.56 MHz is divided by 848 kHz, it becomes 16, so it can be counted 16 times by the internal clock (CLK_INT) during one period of the TYPEA signal. Therefore, if the ADC_OUT signal is counted 16 times by the internal clock (CLK_INT) during one period and the logic high and logic ratio during one period of the ADC_OUT signal is 1:1, it will be determined as a normal signal.

However, since minute changes may occur in input/output timing of various signals depending on the circuit configuration, complexity, etc., a slight margin or tolerance may be provided. For example, if the number of times counted by the internal clock CLK_INT is less than 20, it may be determined as a normal signal. In addition, if the number of times the logic high is counted by the internal clock CLK_INT exceeds 20 times, a logic low value may be forcibly output from the time when the count exceeds 20 times. This is because the determination criterion as a normal signal is set to be within 20 counts by the internal clock CLK_INT. This is shown in the section corresponding to the damping component of FIG. 7A. In the logic high section of the damping section (shown as 5th), the count by the internal clock (CLK_INT) is 22 times, but after counting only 20 times, it can be seen that the level-filtered signal (LF_OUT) becomes "0". have.

In addition, in consideration of minute changes in input/output timing of various signals according to the configuration of the circuit diagram, the ratio of logic high and logic low cannot be exactly 1:1, and therefore, it can be determined as a normal signal if it is within a predetermined range. For example, in one pulse period of the level-filtered signal LF_OUT, if the ratio of level high counted by the internal clock CLK_INT (ie, duty ratio) is within 30~70%, it is determined as a normal signal. can However, it will be well understood that this ratio may be variously set according to factors such as signal quality and communication environment.

It will be described with reference to FIGS. 7A and 7B as follows. In the first section of the graph, the ratio of logic high and logic low counted by the internal clock CLK_INT is 9:9, and the ratio of logic high (ie, duty ratio) is 50%. In the second section, the ratio of logic high and logic low is 4:12, and the ratio of logic high is 25%. In the third section, the ratio of logic high and logic low is 12:4, and the ratio of logic high is 75%. In the fourth section, the ratio of logic high and logic low is 10:10, and the ratio of logic high is 50%. And, the ratio of logic high and logic low in the last damping period is 20:0, and the ratio of logic high is 100%.

As shown in FIG. 7A , 22 times were originally counted in the logic high section of the damping section, but as described above, the logic low value is forcibly output when the 20 counts are finished. That is, with respect to the level-filtered signal LF_OUT, only signals of the first and fourth sections may be determined as normal signals, and signals and damping components of the second to third sections may be determined as noise. The timing-filtered signal LF_TF_OUT is transmitted to the pattern filter 540 (refer to FIG. 3B ).

8A to 8C are diagrams illustrating a method of removing noise included in a timing-filtered signal using predetermined pattern information. The pattern-filtering operation may be performed by a pattern filter (see FIG. 3B , 540 ). The pattern filter (refer to FIG. 3B , 540 ) may receive the timing-filtered signal LF_TF_OUT and remove noise from the timing-filtered signal LF_TF_OUT by using predetermined pattern information.

The predetermined pattern information may be determined based on a characteristic or protocol of a signal received through an antenna. For example, assume the case of an NFC reader (Near Field Communication reader) that transmits and receives a TYPEA signal. If, as shown in FIG. 8A, four consecutive pulses are input, it will be determined that this is a normal signal. However, if four consecutive pulses are not input as shown in FIG. 8B or 8C, it may be determined as noise. In the drawings, a case in which four consecutive pulses are input has been described as an example. However, it can be recognized as a normal signal even when 8 consecutive pulses are input according to the protocol that defines the TYPEA signal, or when consecutive pulses of different numbers are input.

Whether it is a continuous pulse or not may be determined by referring to the number of times counted by the internal clock CLK_INT. For example, when the wireless communication device transmits and receives a TYPEA signal having a frequency of 848 kHz, the frequency of the internal clock CLK_INT may be 13.56 MHz. If it is counted 16 times by the internal clock (CLK_INT) per one pulse period of the TYPEA signal, it will be determined that a continuous pulse is input. However, a minute difference may occur in the input timing of the clock depending on the design and complexity of the circuit. So, you can put some margin. For example, when the number of times counted by the internal clock CLK_INT is less than 20 times, it may be determined that a continuous pulse is input.

In the case of Figure 8b, since the counting number of times by the internal clock (CLK_ITN) from the rising edge of the first pulse of the timing-filtered signal to the rising edge of the second pulse exceeds 20 times, 4 consecutive pulses are input has not been judged to have been In addition, three consecutive pulses are input from the second pulse to the fourth pulse, but since four consecutive pulses are not input as a whole, it is not determined as a normal signal according to the protocol defining the TYPEA signal. As a result, all the signals as shown in FIG. 8B are filtered (removed) by the pattern-filtering operation.

Similarly, in the case of FIG. 8C as well, since the number of counts by the internal clock CLK_INT exceeds 20 or more between the rising edges of the second pulse and the third pulse, it is not determined that consecutive pulses are input. Accordingly, all of the signal as shown in FIG. 8C is also filtered (removed) by the pattern-filtering operation.

9 is a diagram illustrating a process of correcting the duty of a pattern-filtered signal. In the case of the level-filtering, timing-filtering, and pattern-filtering processes described above, the filtering operation is performed with a certain margin (for example, if the number of counting by the internal clock is within 20, it is determined as a normal signal). Therefore, the duty of the pattern-filtered signal LF_TF_PF_OUT may not be exactly 50%. Therefore, the operation of finally correcting the duty is performed. As shown in Fig. 9, the second and third pulses of the pattern-filtered signal are finally corrected to have a duty of 50%.

10 is a flowchart illustrating filtering operations of a wireless communication device according to an embodiment of the present invention.

In step S110, mask information may be generated. The mask information may be generated by sampling the preamble section of the output ADC_OUT of the analog-to-digital converter (see FIG. 3B , 510 ). Information on UTP and LTP of noise may be obtained through the sampling process.

In step S120 , a level-filtering operation may be performed. The level filtering operation may be performed using the mask information generated in step S110. A signal that exists between the UTP and LTP of noise is considered noise and may be filtered. For example, a section from the point where the rising edge of ADC_DATA and UPT intersect to the point where the falling edge of ADC_DATA and LTP intersect may be recognized as a digital signal "1". On the other hand, a section from the point where the falling edge of ADC_DATA and LTP intersect to the point where the rising edge of ADC_DATA and UPT intersect may be recognized as a digital signal "0". A 1-bit digital signal may be output by the level filtering operation.

In step S130 , a timing-filtering operation may be performed. The timing-filtering operation may remove noise or damping components not removed by the level-filtering operation. The timing-filtering operation may be performed by referring to the ratio of logic high and logic low among numbers counted by the internal clock CLK_INT per one pulse of the level-filtered output. For example, if the ratio of the counting number in logic high is out of 30 to 70%, it may be determined as noise and filtered. However, it will be well understood that this ratio may be variously set according to factors such as signal quality and communication environment.

In step S140 , a pattern-filtering operation may be performed. For example, if there are 4, 8, or more consecutive pulses, it may be determined as a normal signal. However, it will be well understood that it is due to the characteristics of the TYPEA signal that there must be 4, 8, or more consecutive signals.

In step S150 , an operation of correcting the duty of the pattern-filtered signal may be performed. This is because, since the filtering operation is performed with a certain margin in the previous filtering steps, the pattern-filtered signal may not have a duty of exactly 50%.

11 is a flowchart illustrating an exemplary operation of the timing-filtering operation shown in FIG. 10 .

In operation S132 , it may be determined whether a ratio of a logic high to a logic low included in the level-filtered signal counted by the internal clock CLK_INT exceeds a predetermined ratio. Assuming that the NFC reader transmits and receives a TYPEA signal having 848 kHz and the internal clock (CLK_INT) operates at 13.56 MHz, it is counted 16 times by the internal clock (CLK_INT) per one pulse of the level-filtered signal . At this time, if the ratio of logic high and logic low is 1:1 among 16 counting times, it will be a normal signal. However, since minute changes may occur in input/output timing of various signals depending on the circuit configuration, complexity, etc., a slight margin or tolerance may be provided. An operation branch occurs according to the determination result. If the ratio of the logic high to the logic low does not deviate from a predetermined range (No), it may be determined as a normal signal. However, if the ratio of logic high and logic low is out of a predetermined range (Yes), the process moves to step S134.

In step S134 , a timing-filtering operation may be performed. At this time, if the ratio of the logic high among the counts by the internal clock CLK_INT is out of the range of 30 to 70%, the timing-filtering operation may be performed. However, it will be well understood that this ratio may be variously set according to factors such as signal quality and communication environment.

12 is a flowchart illustrating an exemplary operation of the pattern-filtering operation shown in FIG. 10 .

In step S142 , it may be determined whether the number of times counted by the internal clock CLK_INT exceeds a predetermined number between the rising edge of one pulse of the timing-filtered signal and the rising edge of the next pulse. This is to determine whether the pulses counted by the internal clock CLK_INT are normal signals.

For example, it is assumed that a TYPEA signal having a frequency of 848 kHz is transmitted and received and the frequency of the internal clock CLK_INT is 13.56 MHz. At this time, if the TYPEA signal is counted 16 times by the internal clock (CLK_INT) per pulse period, it is determined that a continuous signal is input, and thus a normal signal is determined. However, a minute difference may occur in the input timing of the pulse depending on the design and complexity of the circuit. So, you can put some margin. For example, when the number of times counted by the internal clock INT_CLK is less than 20 times, it is determined that a continuous signal is input and thus a normal signal may be determined. An operation branch occurs according to the determination result. If the counted number exceeds a predetermined number (Yes), the flow moves to step S144. If the counted number does not exceed the predetermined number (No), the flow moves to step S146.

In step S144 , a pattern-filtering operation may be performed. If the counting number from the rising edge of the first pulse to the rising edge of the second pulse of the timing-filtered signal exceeds a predetermined number (eg, 20 times), the first pulse is noise and may be filtered.

In step S146, it may be determined whether there are four consecutive pulses. This is a case of transmitting and receiving a TYPEA signal, and it can be determined as a normal signal even when 8 consecutive pulses exist. And, in the case of transmitting and receiving a signal of a different type, the number of consecutive pulses, which is a criterion for determining whether the signal is a normal signal, may change. Whether the pulses are continuous may be determined according to whether the number of times the interval between the rising edges of adjacent pulses is counted by the internal clock CLK_INT exceeds a predetermined number (eg, 20 times). An operation branch occurs according to the determination result. If there are four consecutive pulses (Yes), the pattern-filtering operation ends. If four consecutive pulses do not exist (No), the flow moves to step S148.

In step S148, a pattern-filtering operation may be performed. Even if the pattern-filtering operation has been performed in step S144, if there are no four consecutive pulses, this is because noise.

In this figure, it has been described that the first filtering is performed by determining the number of counting times between the rising edges of adjacent pulses, and the second filtering is performed by determining whether there are four consecutive pulses. However, the pattern-filtering operation may be performed by various other methods. For example, if there is a pulse whose counting number from its rising edge to the rising edge of the next pulse exceeds 20, it is determined whether there are four consecutive pulses except for this, and one pattern-filtering operation is performed. can also be done

According to the NFC reader implemented with the calibrator according to an embodiment of the present invention, or a wireless communication device including the same, removing noise included in a wireless signal and removing damping located at the end of the wireless signal separate and deal with As a result, it is possible to solve problems such as shortening of a communication distance of an NFC reader, or a wireless communication device including the same, caused by a conventional processing method that simultaneously removes noise and damping components.

13 is a block diagram illustrating a portable terminal to which a wireless communication device according to an embodiment of the present invention is applied. Referring to FIG. 13 , the portable terminal 1000 to which an NFC reader is applied according to an embodiment of the present invention includes an image processing unit 1100 , a wireless transceiver 1200 , an audio processing unit 1300 , an image file generation unit 1400 , It may include a nonvolatile memory device 1500 , a user interface 1600 , and a controller 1700 .

The image processing unit 1100 may include a lens 1110 , an image sensor 1120 , an image processor 1130 , and a display unit 1140 . The wireless transceiver 1200 may include an antenna 1210 , an RF unit 1220 , and a modem 1230 . The NFC reader according to an embodiment of the present invention may be implemented in the RF unit 1220, and may be implemented in various forms. The audio processing unit 1300 may include an audio processor 1310 , a microphone 1320 , and a speaker 1330 .

The nonvolatile memory device 1500 may be provided as a memory card (MMC, eMMC, SD, micro SD) or the like. In addition, the controller 1700 may be provided as a system-on-chip (SoC) for driving an application program, an operating system, and the like. The kernel of the operating system driven in the system-on-chip may include an I/O scheduler and a device driver for controlling the nonvolatile memory device 1500 . The device driver may control the access performance of the nonvolatile memory device 1500 by referring to the number of synchronization queues managed by the I/O scheduler, or may control the CPU mode and DVFS level inside the SoC.

The nonvolatile memory device and/or the memory controller may be mounted using various types of packages. For example, a flash memory device and/or a memory controller may include a Package on Package (PoP), Ball grid arrays (BGAs), Chip scale packages (CSPs), Plastic Leaded Chip Carrier (PLCC), Plastic Dual In-Line Package (PDIP). ), Die in Waffle Pack, Die in Wafer Form, Chip On Board(COB), Ceramic Dual In-Line Package(CERDIP), Plastic Metric Quad Flat Pack(MQFP), Thin Quad Flatpack(TQFP), Small Outline(SOIC) , Shrink Small Outline Package(SSOP), Thin Small Outline(TSOP), System In Package(SIP), Multi Chip Package(MCP), It can be mounted using packages such as Wafer-level Fabricated Package (WFP) and Wafer-Level Processed Stack Package (WSP).

It will be apparent to those skilled in the art that the structure of the present invention can be variously modified or changed without departing from the scope or spirit of the present invention. In view of the foregoing, it is contemplated that the present invention includes such modifications and variations of the present invention provided that they fall within the scope of the following claims and their equivalents.

100: receiver 200, 510: analog-to-digital converter 300: calibrator 310, 520: noise detector 320, 530: level/timing filter 330, 540: pattern filter 340, 550: duty corrector 400: modem 500: digital calibrator