CN104124997A - Method for controlling a modulation index of a near field communication device, and associated apparatus - Google Patents
Method for controlling a modulation index of a near field communication device, and associated apparatus Download PDFInfo
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- CN104124997A CN104124997A CN201410169317.8A CN201410169317A CN104124997A CN 104124997 A CN104124997 A CN 104124997A CN 201410169317 A CN201410169317 A CN 201410169317A CN 104124997 A CN104124997 A CN 104124997A
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Abstract
A method for controlling a modulation index of a near field communication (NFC) device includes: in a calibration mode of the NFC device, temporarily coupling a receiver of the NFC device to a transmitter of the NFC device to form a probing path between the receiver and the transmitter; and in the calibration mode of the NFC device, dynamically adjusting at least one portion of a plurality of modulation parameters corresponding to the modulation index according to probed results of outputs of the transmitter, in order to calibrate the modulation index, for use of transmitting through the transmitter in a normal mode of the NFC device. An associated apparatus is also provided.
Description
[technical field]
The present invention is about near-field communication (near field communication, NFC) the dynamic modulation index of equipment calibration (dynamic modulation index calibration), especially about a kind of method and device of controlling the modulation index of near-field communication equipment.
[background technology]
According to prior art, traditional NFC equipment can be designed to utilize predetermined ASK data rate to communicate.In practice, conventionally need in advance (for example, in the design phase of traditional NFC equipment, or during the manufacture of traditional NFC equipment) to determine the appropriate value of modulation index, so that traditional NFC equipment reaches better performance.Because modulation index depends on many factors, such as the antenna size of traditional NFC equipment, target antenna distance (for example, the antenna of tradition NFC equipment and the distance between the target antenna of other equipment) and the NFC antenna matching network of traditional NFC equipment, therefore may there are some problems.For example, the false supposition of the designer of traditional NFC equipment possibility based target antenna distance has designed traditional NFC equipment, causes the performance of traditional NFC equipment to become in some cases and can not be accepted by user.In another example, the manufacturer of traditional NFC equipment may manually adjust traditional NFC equipment for the different target value of modulation index, thereby causes relevant cost to subdue, for example the additional effort cost of manual adjustments tradition NFC equipment.In another example, because modulation index depends on antenna impedance, and this antenna impedance is conventionally to environment sensitive, thereby because magnetic Field Coupling has changed its resonance frequency, thereby in metal surface, change significantly antenna impedance in the situation of in-plant auxiliary antenna etc., the performance of traditional NFC equipment may become and can not be accepted by user.Therefore the modulation index that, needs a kind of new method to improve the NFC equipment in various situations is controlled.
[summary of the invention]
In view of this, the invention provides a kind of method and device thereof of controlling the modulation index of near-field communication equipment, to address the above problem.
According at least one preferred embodiment of the present invention, provide a kind of for controlling the method for the modulation index of near-field communication equipment, the method comprises: in the calibration mode of NFC equipment, the receiver of this NFC equipment is temporarily coupled to the transmitter of this NFC equipment to form the detective path between this receiver and this transmitter; And in this calibration mode of this NFC equipment, according to the result of detection of the output of this transmitter, dynamically adjust at least one part corresponding to a plurality of modulation parameters of this modulation index, to calibrate this modulation index, for the normal mode at this NFC equipment, pass through the transmission of this transmitter.
According at least one preferred embodiment of the present invention, provide a kind of for controlling the device of the modulation index of near-field communication equipment, at least a portion that this device comprises this NFC equipment.This device comprises transmitter, receiver and control circuit.This transmitter, receiver and control circuit are positioned in the chip of this NFC equipment, and this control circuit is coupled to this transmitter and this receiver.This transmitter is set to as this NFC equipment sending data; This receiver is set to as this NFC equipment receiving data.In addition,, in the calibration mode of this NFC equipment, this receiver is temporarily coupled to this transmitter to form the detective path between this receiver and this transmitter.In addition, this control circuit is set to control the operation of this NFC equipment, wherein in this calibration mode of this NFC equipment, this control circuit is dynamically adjusted at least one part corresponding to a plurality of modulation parameters of this modulation index according to the result of detection of the output of this transmitter, to calibrate this modulation index, for the normal mode at this NFC equipment, pass through the transmission of this transmitter.
The method and apparatus of the modulation index of above-mentioned control near-field communication equipment can reduce correlative charges, Optimal performance.
[accompanying drawing explanation]
Fig. 1 for according to first embodiment of the invention for controlling the schematic diagram of device 100 of the modulation index of near-field communication (NFC) equipment.
Fig. 2 illustrates according to the NFC system 200 of the above-mentioned NFC equipment that comprises embodiment shown in Fig. 1 of the embodiment of the present invention.
Fig. 3 illustrate according to the embodiment of the present invention for controlling the flow chart of method 300 of the modulation index of NFC equipment.
Fig. 4 illustrates the control program that relates to method shown in Fig. 3 300 according to the embodiment of the present invention.
Fig. 5 illustrates some signals that are associated that relate to method shown in Fig. 3 300 according to the embodiment of the present invention.
Fig. 6 illustrates the workflow 600 that relates to according to an embodiment of the invention method shown in Fig. 3 300.
[embodiment]
In the middle of specification and claim, used some vocabulary to censure specific element.Those skilled in the art should understand, and same element may be called with different nouns by electronic installation manufacturer.This specification and claims are not used as distinguishing the mode of element with the difference of title, but the difference in function is used as the criterion of distinguishing with element.In the whole text, in the middle of specification and claim, be open term mentioned " comprising ", therefore should be construed to " comprise but be not limited to ".In addition, " coupling " word comprises directly any and is indirectly electrically connected means at this.Therefore, if describe first device in literary composition, be couple to the second device, represent that this first device can directly be electrically connected in this second device, or be indirectly electrically connected to this second device by other devices or connection means.
Please refer to Fig. 1, it is for being used for controlling the schematic diagram of device 100 of the modulation index of near-field communication (NFC) equipment according to first embodiment of the invention, wherein installs 100 at least a portion (for example, part or all of) that can comprise NFC equipment.For instance, device 100 can comprise a part for above-mentioned NFC equipment, more specifically, can be at least one hardware circuit, for example at least one integrated circuit (IC) in NFC equipment.In another example, device 100 can be whole NFC equipment above-mentioned.In another example, device 100 can comprise NFC system, and it comprises above-mentioned NFC equipment.
As shown in Figure 1, device 100 can comprise chip 110, it can be used as the example of above-mentioned at least one integrated circuit, and can comprise antenna matching network and electromagnetic interference (electromagnetic interference, EMI) filtration module 130 (being labeled as for simplicity " antenna matching network and EMI filtering " in Fig. 1) and NFC antenna 140, wherein antenna matching network and EMI filtration module 130 can comprise antenna matching network and electromagnetic interface filter (for it is not shown for purpose of brevity).In practice, electromagnetic interface filter above-mentioned can be with some impedance components (for example, one or more inductors and/or one or more capacitor in the present embodiment) realize, and antenna matching network above-mentioned can for example, be realized with some impedance components (, in the present embodiment one or more inductors and/or one or more capacitor).In addition, chip 110 can comprise control circuit, and for example digital baseband circuit 112, and can comprise service module 114 (being labeled as for simplicity " Sx " in Fig. 1).Control circuit, for example digital baseband circuit 112 is set to control the operation of NFC equipment.In addition, this chip 110 can also comprise transceiver and rectifier module 118 (for be labeled as for purpose of brevity " Tx/Rx & rectifier " in Fig. 1).For example, transceiver and rectifier module 118 can comprise transmitter 118T (being labeled as for simplicity " Tx " in Fig. 1), receiver 118R (being labeled as for simplicity " Rx " in Fig. 1) and rectifier 118C.When needed, service module 114 provides respectively to transmitter 118T and receiver 118R to have frequency the signal LO2 of (for example 13.56MHz) and have the signal LO1 of another frequency (for example 12.05MHz).As shown in Figure 1, transmitter 118T can be coupled to one group of transmitter terminal TXP and the TXN of chip 110, wherein, transmitter 118T is set to carry out the equipment transmission data for NFC by this group transmitter terminal TXP and TXN, antenna matching network and EMI filtration module 130 and NFC antenna 140.Receiver 118R can be coupled to one group of receiver terminal RXP and the RXN of chip 110, and wherein receiver 118R is set to carry out the equipment receiving data for NFC by this group receiving terminal RXP and RXN, antenna matching network and EMI filtration module 130 and NFC antenna 140.Rectifier 118C can be couple to one group of card terminal CardP and the CardN of chip 110, and wherein, rectifier 118C is set to carry out rectification, collection of energy and passive load modulation operations for NFC equipment by this group card terminal CardP and CardN.
As shown in Figure 1, for understanding better, signal LO1 and LO2 have been illustrated.This,, only for illustration purpose, is not meant to be limitation of the present invention.According to some variations of this embodiment, the structure of device 100 is not limited to utilize the receiver of particular type such as direct conversion receiver.For instance, the receiver of another kind of type in some changes, for example Direct Sampling receiver can be used in the architecture of device 100, and the receiver of other type can be used in the architecture of equipment 100 in other change.
Fig. 2 illustrates the NFC system 200 according to the embodiment of the present invention, comprises above-mentioned NFC equipment embodiment illustrated in fig. 1.Wherein polling set-up (polling device) 210 and interception device (listening device) 220 can represent 2 NFC terminals of NFC system 200.As shown in Figure 2, polling set-up 210 and interception device 220 can have respectively the electronic circuit of oneself, also can have themselves NFC antenna.
In order to understand better, interception device 220 can be used as an example of above-mentioned NFC equipment, and polling set-up 210 can be used as an example of another equipment embodiment illustrated in fig. 1.According to the present embodiment, NFC system 200 can transmit data with different data rates between above-mentioned 2 NFC terminals are as polling set-up 210 and interception device 220.For example, polling set-up 210 can be that NFC card reader (reader) and interception device 220 can be passive label (passive tag) or card.Because interception device 220 may operate when lacking battery electric quantity, so interception device 220 can be designed to collecting energy field (field) (as at least a portion electromagnetic field) from importing into.
By means of using architecture shown in Fig. 1, in the situation that modulation index can be dynamically adjusted, more specifically, can be calibrated to be suitable for the environment of NFC system 200, the problem of correlation technique can be resolved.
Fig. 3 illustrates according to the embodiment of the present invention for controlling the flow chart of method 300 of the modulation index of NFC equipment.Method 300 shown in Fig. 3 can be applicable to the device 100 shown in Fig. 1, more specifically, can be applied to the chip 110 shown in Fig. 1.The method is described below.
In step 310, in the calibration mode of NFC equipment, receiver 118R is temporarily couple to transmitter 118T, to form the detective path between receiver 118R and transmitter 118T.For example, switch element can be installed on detective path, and for optionally activating or forbidding detective path, and digital baseband circuit 112 can temporarily be couple to transmitter 118T to activate detective path by receiver 118R by opening switch element.This,, only for illustration purpose, is not meant to be limitation of the present invention.In another example, above-mentioned switch element needn't be installed, wherein said receiver 118R is coupled to transmitter 118T, to form the detective path between receiver 118R and transmitter 118T.
In step 320, in the calibration mode of NFC equipment, digital baseband circuit 112 is according to the result of detection of the output of transmitter 118T, dynamically adjust at least a portion corresponding to a plurality of modulation parameters of modulation index, so that calibration modulation index, for transmitting by transmitter 118T in the normal mode at NFC equipment.Conventionally, digital baseband circuit 112 is opened receiver 118R and transmitter 118T, and some calibration operations can carry out under calibration mode.
More specifically, service module 114, it is placed in the chip 110 of NFC equipment and is couple to digital baseband circuit 112 and transmitter 118T and receiver 118R, be set to the calibration mode of NFC equipment to transmitter 118T provide there is first frequency first signal (for example, the signal LO2 with 13.56MHz frequency), and the secondary signal of providing to receiver 118R to have second frequency under the calibration mode of NFC equipment (for example, the signal LO1 with 12.05MHz frequency), and allow receiver 118R to extract intermediate frequency (intermediate frequency from result of detection, IF) signal, be used for calibrating modulation index, wherein said first frequency is in the normal mode of NFC equipment, to pass through transmitter 118T for the wave frequency of carrying of transfer of data, and described second frequency is different from first frequency.
Fig. 4 illustrates the control program that relates to method shown in Fig. 3 300 according to the embodiment of the present invention.As shown in Figure 4, the service module 114 of the present embodiment can comprise oscillator (being labeled as for simplicity " OSC " in Fig. 4) and a set of division device (being labeled as for simplicity " DIV1 " and " DIV2 " in Fig. 4).This set of division device can be used to the output of described oscillator to carry out divide operation, for example, for example, to produce above-mentioned first signal (the signal LO2, with 13.56MHz frequency) and above-mentioned secondary signal (the signal LO1 with 12.05MHz frequency).In the present embodiment, receiver 118R is coupled to transmitter 118T by least one impedance component, to form the detective path between receiver 118R and transmitter 118T.For example, above-mentioned at least one impedance component can comprise resistor and the capacitor of Fig. 4 upper right side shown in around.More specifically, one of them of this group receiver terminal RXP and RXN (receiver terminal RXP as shown in Figure 4) is temporarily coupled to this group transmitter terminal TXP of transmitter 118T and one of them (transmitter terminal TXP as shown in Figure 4) of TXN by antenna matching network and EMI filtration module 130, to form the detective path between receiver 118R and transmitter 118T, wherein said result of detection can be received by receiver 118R by one of them (receiver terminal RXP as shown in Figure 4) of above-mentioned this group receiver terminal RXP and RXN.
According to the present embodiment, receiver 118R can comprise the first converting unit and the second converting unit, wherein, the first converting unit is set under the calibration mode of NFC equipment, according to secondary signal, change by this group receiver terminal RXP and above-mentioned one of them result of detection receiving of RXN to produce the first of M signal, and described the second converting unit is set under the calibration mode of NFC equipment, according to the phase shift signalling of secondary signal, change by this group receiver terminal RXP and above-mentioned one of them result of detection receiving of RXN to produce the second portion of M signal.More specifically, the first converting unit and the second converting unit can be the first frequency mixer and the second frequency mixer (it around illustrates in upper right side and the lower right of the 118R of receiver shown in Fig. 4 respectively), and receiver 118R can comprise 90 degree phase-shift units (for be labeled as for purpose of brevity " 90 ° " in Fig. 4), and can comprise one group of filter of the output that is coupled to respectively described the first frequency mixer and described the second frequency mixer, be coupled to respectively one group of programmable gain amplifier (programmable-gain amplifier of the output of described one group of filter, PGA), and one group of analog to digital converter (the analog-to-digital converter that is coupled to respectively the output of described one group of programmable gain amplifier, ADC).For example, in the calibration mode of NFC equipment, described the first frequency mixer is set to the result of detection and secondary signal (the signal LO1 for example, with the 12.05MHz frequency) mixing that by this group receiver terminal RXP and RXN above-mentioned one of them (receiver terminal RXP as shown at Fig. 4), receive to produce the above-mentioned first of M signal.In addition, in the calibration mode of NFC equipment, the second frequency mixer is for example set to, by by this group receiver terminal RXP and above-mentioned one of them (receiver terminal RXP as shown at Fig. 4) result of detection receiving of RXN and the phase shift signalling of above-mentioned secondary signal (, the phase shift signalling with the signal LO1 of 12.05MHz frequency) mixing produces the above-mentioned second portion of M signal, and wherein in this embodiment, phase shift signalling can be the 90 degree phase shift signallings that produce from 90 degree phase-shift units.In practice, this group filter can be for the above-mentioned M signal of filtering, and the filtering result of wherein said M signal is imported into this group programmable gain amplifier.This group programmable gain amplifier can be used to according to the gain control parameter DA_PGA_G[5:0 of this group programmable gain amplifier of receiver 118R], with arbitrarily corresponding to controlling parameter DA_PGA_GC[5:0] the gain of this group programmable gain amplifier amplify the filtering result of this intermediate-freuqncy signal.This group analog to digital converter can be used for the amplification result from this group programmable gain amplifier (being the amplification result of the filtering result of M signal) to carry out analog-to-digital conversion operation, to produce the numeral output AD_ADC_ID[5:0 that corresponds respectively to I channel and Q channel] and AD_ADC_QD[5:0].
To note that in the embodiment shown in fig. 4, in order understanding better, some details of receiver 118R to be described.This,, only for illustration purpose, is not meant to be limitation of the present invention.According to some variations of this embodiment, the structure of device 100 is not limited to utilize the receiver of particular type such as direct conversion receiver.For example, the receiver of another kind of type in some change, for example Direct Sampling receiver can be used in the architecture of device 100, and in other change the receiver of other type can the architecture for equipment 100 in.
As shown in Figure 4, transmitter 118T can comprise multiplexer (being labeled as for simplicity " MUX " in Fig. 4), and can comprise power amplifier (being labeled as for simplicity " PA " in Fig. 4).This multiplexer be set to calibration mode and normal mode in any one according to modulated data signal MOD_DATA, multiplexed (multiplex) above-mentioned modulation parameter, as modulation parameter RG_PA_A_OUT[7:0] and DA_PA_B_OUT[7:0], wherein modulated data signal MOD_DATA is used to carry data at normal mode.Based on above-mentioned first signal (for example, the signal LO2 with 13.56MHz frequency), power amplifier is set to according to the multiplexed Output rusults from multiplexer, produce the output (output of mentioning, for example one group of difference output in the present embodiment) of transmitter 118T in step 320.For example, in multiplexed result, be modulation parameter RG_PA_A_OUT[7:0] in the situation that, the output amplitude of transmitter 118T is corresponding to modulation parameter RG_PA_A_OUT[7:0], wherein the output frequency of transmitter 118T equals the frequency of above-mentioned first signal (for example 13.56MHz).In another example, in multiplexed result, be modulation parameter DA_PA_B_OUT[7:0] in the situation that, the output amplitude of transmitter 118T is corresponding to modulation parameter DA_PA_B_OUT[7:0], wherein the output frequency of transmitter 118T equals the frequency of above-mentioned first signal (for example 13.56MHz).
Fig. 5 illustrates some signals that are associated that relate to method shown in Fig. 3 300 according to the embodiment of the present invention.Please note, the output signal obtaining from the output of above-mentioned this group programmable gain amplifier can be regarded as one group of difference output, and the programmable gain amplifier output signal PGA_OUT shown in Fig. 5 can represent the voltage difference between the output of this group programmable gain amplifier.
In the present embodiment, modulated data signal MOD_DATA can be corresponding to logical value 0 or logical value 1, wherein two voltage levels of the modulated data signal MOD_DATA shown in Fig. 5 compared with low level indication logical value 0, and the higher level of two voltage levels of the modulated data signal MOD_DATA shown in Fig. 5 indication logical value 1.For example, at modulated data signal MOD_DATA, corresponding to logical value 1 in the situation that, multiplexed result is modulation parameter RG_PA_A_OUT[7:0], and the output amplitude Vmax of transmitter 118T is corresponding to modulation parameter RG_PA_A_OUT[7:0].More specifically, in calibration mode, by means of corresponding to described modulation parameter RG_PA_A_OUT[7:0] the output amplitude Vmax of transmitter 118T, from the amplitude Vmax ' of the programmable gain amplifier output signal PGA_OUT of above-mentioned this group programmable gain amplifier output of mentioning, can be detected, wherein the ratio of the amplitude Vmax ' of programmable gain amplifier output signal PGA_OUT and the output amplitude Vmax of transmitter 118T can be by the above-mentioned control parameter DA_PGA_GC[5:0 of adjusting] adjust.In another example, at modulated data signal MOD_DATA corresponding to logical value 0 in the situation that, multiplexed result is modulation parameter DA_PA_B_OUT[7:0], and the output amplitude Vmin of transmitter 118T is corresponding to modulation parameter DA_PA_B_OUT[7:0].More specifically, in calibration mode, by means of corresponding to described modulation parameter DA_PA_B_OUT[7:0] the output amplitude Vmin of transmitter 118T, from the amplitude Vmin ' of the programmable gain amplifier output signal PGA_OUT of above-mentioned this group programmable gain amplifier output of mentioning, can be detected, wherein the ratio of the amplitude Vmin ' of programmable gain amplifier output signal PGA_OUT and the output amplitude Vmin of transmitter 118T can be by the above-mentioned control parameter DA_PGA_GC[5:0 of adjusting] adjust.This,, only for illustration purpose, is not meant to be limitation of the present invention.According to some of this embodiment, change, architecture can change, and wherein programmable gain amplifier gain can be adjusted so that within signal falls into ADC dynamic range.In practice, in calibration mode, digital baseband circuit 112 can be adjusted and control parameter DA_PGA_GC[5:0] calibrate the ratio of the ratio of amplitude Vmax ' and amplitude Vmax or amplitude Vmin ' and amplitude Vmin, to calibrate above-mentioned modulation index, it can represent following formula:
m＝(Vmax-Vmin)/(Vmax+Vmin)；
Wherein, symbol " m " can represent modulation index.
According to the present embodiment, in the calibration mode of NFC equipment, digital baseband circuit 112 can temporarily be set modulated data signal MOD_DATA corresponding to logical value 1, and modulation parameter RG_PA_A_OUT[7:0] and DA_PA_B_OUT[7:0] the first modulation parameter be set to equal a particular value, to calibrate the gain control parameter DA_PGA_GC[5:0 of this group programmable gain amplifier of receiver 118R].This,, only for illustration purpose, is not meant to be limitation of the present invention.According to some of this embodiment, change, architecture can change, and wherein programmable gain amplifier gain can be adjusted so that within signal falls into ADC dynamic range.More specifically, described the first modulation parameter is used to the maximum voltage (for example amplitude Vmax) at the output envelope of calibration mode and one of any described transmitter 118T of control of normal mode, wherein modulation parameter RG_PA_A_OUT[7:0] can be used as the example of above-mentioned the first modulation parameter.
In addition, in the calibration mode of NFC equipment, gain control parameter DA_PGA_GC[5:0] calibration complete after, digital baseband circuit 112 can calculate above-mentioned maximum voltage some detected value mean value (for example, the mean value of some detected value of amplitude Vmax, as amplitude Vmax '), wherein, a part for a plurality of digital values of the programmable gain amplifier output of described detected value based on this group programmable gain amplifier obtains.For example, at numeral output AD_ADC_ID[5:0] and AD_ADC_QD[5:0] carry a plurality of above-mentioned digital value in the situation that, digital baseband circuit 112 can be to by numeral output AD_ADC_ID[5:0] and AD_ADC_QD[5:0] some digital values of carrying are averaging, to obtain above-mentioned mean value.Digital baseband circuit 112 can be according to mean value and according to the desired value of modulation index m, further calculate the target detection value (for example the target detection value of amplitude Vmin, as the desired value of amplitude Vmin ') of minimum voltage of the output envelope of transmitter 118T.For example, based on NFC standard, the desired value of modulation index m can equal 10%.In another example, based on NFC standard, the desired value of modulation index m can equal 30%.This,, only for illustration purpose, is not meant to be limitation of the present invention.In another example, the desired value of modulation index m can equal another value.No matter whether the desired value of modulation index m equals 10% or 30% or other values, in the target detection value that calculates above-mentioned minimum voltage (for example, the target detection value of amplitude Vmin, as the desired value of amplitude Vmin ') after, digital baseband circuit 112 can temporarily be set modulated data signal MOD_DATA corresponding to logical value 0, to calibrate modulation parameter RG_PA_A_OUT[7:0 according to the target detection value of minimum voltage] and DA_PA_B_OUT[7:0] the second modulation parameter.More specifically, the second modulation parameter is for example used to, at calibration mode and one of any minimum voltage (amplitude Vmin) of controlling the output envelope of transmitter 118T of normal mode, wherein modulation parameter DA_PA_B_OUT[7:0] can be used as the example of above-mentioned the second modulation parameter.
In addition, digital baseband circuit 112 can dynamically be adjusted described the second modulation parameter (for example, modulation parameter DA_PA_B_OUT[7:0]), to complete calibration modulation index m.For example, digital baseband circuit 112 (for example can dynamically be adjusted described the second modulation parameter, modulation parameter DA_PA_B_OUT[7:0]), until a detected value of minimum voltage equals above-mentioned target detection value, wherein another part of a plurality of digital values of the programmable gain amplifier output of an above-mentioned detected value based on this group programmable gain amplifier obtains.This,, only for illustration purpose, is not meant to be limitation of the present invention.According to some of this embodiment, change, digital baseband circuit 112 can dynamically be adjusted described the second modulation parameter (for example, modulation parameter DA_PA_B_OUT[7:0]), until an above-mentioned detected value of minimum voltage approaches target detection value most.More specifically, digital baseband circuit 112 can dynamically be adjusted described the second modulation parameter (for example, modulation parameter DA_PA_B_OUT[7:0]), until the difference between above-mentioned detected value drops within the scope of the predetermined interval that comprises target detection value.For example, symbol mag_vmin_tgt can represent target detection value, and predetermined interval can be [mag_vmin_tgt-Δ, mag_vmin_tgt+ Δ], and wherein symbol Δ can represent the predetermined tolerance of target detection value mag_vmin_tgt.According to some other variation of the present embodiment, at least one detected value that the above-mentioned detected value of minimum voltage can be extended to minimum voltage (for example, one or more detected values), to guarantee the correctness of calibration in some cases, wherein another part of a plurality of digital values of the programmable gain amplifier output of above-mentioned at least one detected value based on this group programmable gain amplifier obtains.According to some other variation of the present embodiment, digital baseband circuit 112 (for example can dynamically be adjusted described the second modulation parameter, modulation parameter DA_PA_B_OUT[7:0]), for example, until above-mentioned at least one detected value (, above-mentioned one or more detected value) approaches target detection value most.More specifically, digital baseband circuit 112 can dynamically be adjusted described the second modulation parameter (for example, modulation parameter DA_PA_B_OUT[7:0]), until the difference between above-mentioned at least one detected value drops within the scope of the predetermined interval that comprises target detection value.
In practice, at the calibration mode of NFC equipment, gain control parameter DA_PGA_GC[5:0] be calibrated after, gain control parameter DA_PGA_GC[5:0] be indeclinable.In addition, the result of detection of the output of transmitter 118T obtains by above-mentioned detective path conventionally.
In some embodiments of the invention, as some variations of the present embodiment, detective path is not activated under the normal mode of NFC equipment.This,, only for illustration purpose, is not meant to be limitation of the present invention.
Fig. 6 illustrates the workflow 600 that relates to method shown in Fig. 3 300 according to embodiments of the invention.
In step 610, whether digital baseband circuit 112 inspection has any radio frequency (RF) field to be present in (for understanding better, being labeled as " RF field being detected " in Fig. 6) around NFC equipment.More specifically, under the control of digital baseband circuit 112, whether NFC equipment Inspection there is field, and wherein air route (airway) must remove any before calibration starts, and if there is not field, can carry out calibration operation.When RF field being detected and exist, reenter step 610; Otherwise, enter step 620.
In step 620, digital baseband circuit 112 is set modulated data signal MOD_DATA corresponding to logical value 1 (for be labeled as for purpose of brevity " MOD_DATA=1 " in Fig. 6).
In step 630, digital baseband circuit 112 calibration-gain are controlled parameter DA_PGA_GC[5:0] (in Fig. 6, being labeled as for simplicity " calibration PGA gain ").Consequently, digital baseband circuit 112 ride gains are controlled parameter DA_PGA_GC[5:0] be certain value, to guarantee that above-mentioned amplitude Vmin ' can correctly be detected.This,, only for illustration purpose, is not meant to be limitation of the present invention.According to some of this embodiment, change, architecture can change, and wherein, receiver gain (or Rx gain, PGA gain as mentioned above) can be adjusted, so that within received signal falls into ADC dynamic range.For piece calibration performance best in the present embodiment, digital baseband circuit 112 can further not change gain control parameter DA_PGA_GC[5:0 in the subsequent step of workflow 600].
In step 640, digital baseband circuit 112 obtains average amplitude avg_mag, and this can be regarded as an example of the mean value mentioned in embodiment illustrated in fig. 5.More specifically, digital baseband circuit 112 is from numeral output AD_ADC_ID[5:0] and AD_ADC_QD[5:0] obtain at least a portion of a plurality of digital values that the programmable gain amplifier of this group programmable gain amplifier exports, and calculate the average amplitude avg_mag of the wave-shape amplitude (or amplitude) of programmable gain amplifier output signal PGA_OUT.
In step 650, digital baseband circuit 112 parameters mag_vmax equal average amplitude avg_mag (being labeled as for simplicity " mag_vmax=avg_mag " in Fig. 6), and wherein parameter m ag_vmax represents from the above-mentioned amplitude Vmax ' of the programmable gain amplifier output signal PGA_OUT of above-mentioned this group programmable gain amplifier output.
In step 660, digital baseband circuit 112 calculates target detection value mag_vmin_tgt (for example the target detection value of amplitude Vmin, as the desired value of amplitude Vmin ').For example, target detection value mag_vmin_tgt can calculate according to formula below:
mag_vmin_tgt＝((1-m_tgt)/(1+m_tgt))*mag_vmax；
Wherein symbol m_tgt represents the desired value of modulation index m.For example, the desired value m_tgt of modulation index m can equal 10% based on NFC standard.In another example, the desired value m_tgt of modulation index m can equal 30% based on NFC standard.In another example, the desired value m_tgt of modulation index m can equal another value.
In step 670, digital baseband circuit 112 is set modulated data signal MOD_DATA corresponding to logical value 0 (being labeled as for simplicity " MOD_DATA=0 " in Fig. 6).
In step 680, digital baseband circuit 112 for example, by dynamically adjusting described the second modulation parameter (, modulation parameter DA_PA_B_OUT[7:0]) and calibrating above-mentioned amplitude Vmin by use target detection value mag_vmin_tgt as the desired value of amplitude Vmin '.For example, digital baseband circuit 112 can dynamically be adjusted described the second modulation parameter (for example, modulation parameter DA_PA_B_OUT[7:0]), until amplitude Vmin ' reaches target detection value mag_vmin_tgt.In another example, digital baseband circuit 112 (for example can dynamically be adjusted described the second modulation parameter, modulation parameter DA_PA_B_OUT[7:0]), until amplitude Vmin ' approaches target detection value mag_vmin_tgt and falls into predetermined interval [mag_vmin_tgt-Δ, mag_vmin_tgt+ Δ] scope in, wherein symbol Δ can represent the predetermined tolerance of target detection value mag_vmin_tgt.As the result that completes the calibration of amplitude Vmin, modulation index m is properly calibrated, wherein the measurement result of modulation index m should equal or approach very much desired value m_tgt, and uses some experiments of actual silicon chip to show that the overall performance of NFC equipment can be guaranteed.
In literary composition, term used " approaches " and refers to that in acceptable error range, those skilled in the art can solve the technical problem within the scope of certain error, reach described technique effect substantially.For example, " the most approaching " refers to when not affecting result correctness, and what technical staff can accept has the mode of certain error with " being equal to ".
The object of the invention is to calibrate to improve performance by carrying out dynamic modulation index.Advantage of the present invention is, the method and apparatus of the modulation index of above-mentioned control near-field communication equipment can dynamically be adjusted modulation index at any time, and for example, the calibration of modulation index can be triggered at any time based on power supply electrifying or by software sequences.In addition, than prior art, method and apparatus of the present invention can reduce correlative charges, because do not need to change the design of NFC equipment with the variation of responsive antenna size or shape.In addition,, because the modulation index adjustment of the inventive method and device can be carried out adaptively, the performance of each data rate can be optimized.
Though the present invention discloses as above with preferred embodiment; so it is not in order to limit scope of the present invention, any those skilled in the art, without departing from the spirit and scope of the present invention; when doing various changes and retouching, so protection scope of the present invention is when being as the criterion depending on the claim person of defining.
Claims (20)
1. for controlling a method for the modulation index of near-field communication equipment, it is characterized in that, the method comprises:
In the calibration mode of this near-field communication equipment, the receiver of this near-field communication equipment is temporarily coupled to the transmitter of this near-field communication equipment to form the detective path between this receiver and this transmitter; And
In this calibration mode of this near-field communication equipment, according to the result of detection of the output of this transmitter, dynamically adjust at least a portion corresponding to a plurality of modulation parameters of this modulation index, calibrate this modulation index, for pass through the transmission of this transmitter in the normal mode of this near-field communication equipment.
2. the method for claim 1, is characterized in that, also comprises:
In this calibration mode of this near-field communication equipment, the first signal with first frequency is provided to this transmitter, wherein this first frequency is by the carrier frequency of the transfer of data of this transmitter for this normal mode at this near-field communication equipment; And
In this calibration mode of this near-field communication equipment, the secondary signal with second frequency is provided to this receiver, allow this receiver from result of that probe, to extract intermediate-freuqncy signal, for calibrating this modulation index, wherein this second frequency is different from this first frequency.
3. method as claimed in claim 2, is characterized in that, this receiver is coupled to one group of receiver terminal, and this transmitter is coupled to one group of transmitter terminal; And this transmitter that this receiver of this near-field communication equipment is temporarily coupled to this near-field communication equipment also comprises to form the step of the detective path between this receiver and this transmitter:
One of them of this group receiver terminal is temporarily coupled to one of them of this group transmitter terminal, to form this detective path between this receiver and this transmitter;
Wherein result of that probe is by this group receiver terminal one of them be received.
4. method as claimed in claim 3, is characterized in that, also comprises:
In this calibration mode of this near-field communication equipment, according to this secondary signal, change one of them result of that probe receiving by this group receiver terminal, to produce the first of M signal; And
In this calibration mode of this near-field communication equipment, according to the phase shift signalling of this secondary signal, change one of them result of that probe receiving by this group receiver terminal, to produce the second portion of this M signal.
5. method as claimed in claim 4, is characterized in that, the multiplexer in this transmitter is used to the modulated data signal in any one according to this calibration mode and this normal mode, multiplexed this modulation parameter; This modulated data signal is used to carry data under this normal mode, and dynamically adjust at least a portion corresponding to a plurality of modulation parameters of this modulation index according to the result of that probe of the output of this transmitter, the step of calibrating this modulation index further comprises:
In this calibration mode of this near-field communication equipment, temporary transient this modulated data signal of setting is corresponding to logical value 1, and the first modulation parameter that this modulation parameter is set equals a particular value, to calibrate the gain control parameter of one group of programmable gain amplifier of this receiver, wherein, this first modulation parameter is used to control in any one at this calibration mode and this normal mode the maximum voltage of the output envelope of this transmitter;
Wherein the first of this M signal and the second portion of this M signal are inputed to respectively this group programmable gain amplifier.
6. method as claimed in claim 5, is characterized in that, according to the result of that probe of the output of this transmitter, dynamically adjusts at least a portion corresponding to a plurality of modulation parameters of this modulation index, to calibrate the step of this modulation index, further comprises:
In this calibration mode of this near-field communication equipment, complete after the calibration of this gain control parameter, calculate the mean value of the detected value of this maximum voltage, wherein, a part for a plurality of digital values of the programmable gain amplifier output of this detected value based on this group programmable gain amplifier obtains;
According to this mean value and according to the desired value of this modulation index, calculate the target detection value of minimum voltage of the output envelope of this transmitter; And
Temporary transient this modulated data signal of setting is corresponding to logical value 0, to calibrate the second modulation parameter of this modulation parameter according to this target detection value of this minimum voltage, wherein this second modulation parameter be used to this calibration mode and this normal mode one of any in this minimum voltage of output envelope of this transmitter of control.
7. method as claimed in claim 6, is characterized in that, the step of calibrating this second modulation parameter of this modulation parameter according to this target detection value of this minimum voltage also comprises:
Dynamically adjust this second modulation parameter, until at least one detected value of this minimum voltage approaches this target detection value most, wherein another part of a plurality of digital values of the programmable gain amplifier output of this at least one detected value based on this group programmable gain amplifier obtains.
8. method as claimed in claim 5, is characterized in that, in this calibration mode of this near-field communication equipment, after this gain control parameter is calibrated, this gain control parameter is indeclinable.
9. the method for claim 1, is characterized in that, this detective path is not activated under this normal mode of this near-field communication equipment.
10. the method for claim 1, is characterized in that, the result of that probe of the output of this transmitter obtains by this detective path.
11. 1 kinds for controlling the device of the modulation index of near-field communication equipment, and at least a portion that this device comprises this near-field communication equipment, is characterized in that, this device comprises:
Transmitter, is positioned in the chip of this near-field communication equipment, is set to send data into this near-field communication equipment;
Receiver, be positioned in this chip of this near-field communication equipment, be set to as this near-field communication equipment receives data, wherein, in the calibration mode of this near-field communication equipment, this receiver is temporarily coupled to this transmitter to form the detective path between this receiver and this transmitter; And
Control circuit, be positioned in this chip of this near-field communication equipment and be coupled to this transmitter and this receiver, be set to control the operation of this near-field communication equipment, wherein in this calibration mode of this near-field communication equipment, this control circuit is dynamically adjusted at least one part corresponding to a plurality of modulation parameters of this modulation index according to the result of detection of the output of this transmitter, calibrate this modulation index, for pass through the transmission of this transmitter in the normal mode of this near-field communication equipment.
12. devices as claimed in claim 11, is characterized in that, also comprise:
Service module, be positioned in this chip of this near-field communication equipment and be coupled to this control circuit and this transmitter and this receiver, and be set in this calibration mode of this near-field communication equipment, the first signal with first frequency is provided to this transmitter, and in this calibration mode of this near-field communication equipment, the secondary signal with second frequency is provided to this receiver, allows this receiver from result of that probe, to extract intermediate-freuqncy signal, for calibrating this modulation index; Wherein this first frequency is for this normal mode at this near-field communication equipment, to pass through the carrier frequency of the transfer of data of this transmitter, and this second frequency is different from this first frequency.
13. devices as claimed in claim 12, is characterized in that, this receiver is coupled to one group of receiver terminal of this chip, and this transmitter is coupled to one group of transmitter terminal of this chip; One of them of this group receiver terminal is temporarily coupled to one of them of this group transmitter terminal, to form this detective path between this receiver and this transmitter; And result of that probe is received by one of them of this group receiver terminal.
14. devices as claimed in claim 13, is characterized in that, this receiver comprises:
The first converting unit, is set to, in this calibration mode of this near-field communication equipment, according to this secondary signal, change one of them result of that probe receiving by this group receiver terminal, to produce the first of M signal; And
The second converting unit, is set to, in this calibration mode of this near-field communication equipment, according to the phase shift signalling of this secondary signal, change one of them result of that probe receiving by this group receiver terminal, to produce the second portion of this M signal.
15. devices as claimed in claim 14, is characterized in that, this transmitter comprises:
Multiplexer, is set to the modulated data signal in any one according to this calibration mode and this normal mode, multiplexed this modulation parameter, and wherein this modulated data signal is used to carry data under this normal mode;
Wherein, in this calibration mode of this near-field communication equipment, this control circuit is temporarily set this modulated data signal corresponding to logical value 1, and the first modulation parameter that this modulation parameter is set equals a particular value, to calibrate the gain control parameter of one group of programmable gain amplifier of this receiver, wherein, this first modulation parameter is used to control in any one at this calibration mode and this normal mode the maximum voltage of the output envelope of this transmitter; Wherein the first of this M signal and the second portion of this M signal are respectively to the input of this group programmable gain amplifier.
16. devices as claimed in claim 15, it is characterized in that, in this calibration mode of this near-field communication equipment, complete after the calibration of this gain control parameter, this control circuit calculates the mean value of the detected value of this maximum voltage, wherein, a part for a plurality of digital values of the programmable gain amplifier output of this detected value based on this group programmable gain amplifier obtains; This control circuit is according to this mean value and according to the desired value of this modulation index, calculates the target detection value of minimum voltage of the output envelope of this transmitter; And this control circuit is temporarily set this modulated data signal corresponding to logical value 0, to calibrate the second modulation parameter of this modulation parameter according to this target detection value of this minimum voltage, wherein this second modulation parameter be used to this calibration mode and this normal mode one of any in this minimum voltage of output envelope of this transmitter of control.
17. devices as claimed in claim 16, it is characterized in that, this control circuit is dynamically adjusted this second modulation parameter, until at least one detected value of this minimum voltage approaches this target detection value most, wherein another part of a plurality of digital values of the programmable gain amplifier output of this at least one detected value based on this group programmable gain amplifier obtains.
18. devices as claimed in claim 15, is characterized in that, in this calibration mode of this near-field communication equipment, after this gain control parameter is calibrated, this gain control parameter is indeclinable.
19. devices as claimed in claim 11, is characterized in that, this detective path is not activated under this normal mode of this near-field communication equipment.
20. devices as claimed in claim 11, is characterized in that, the result of that probe of the output of this transmitter obtains by this detective path.
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US201361816953P | 2013-04-29 | 2013-04-29 | |
| US61/816,953 | 2013-04-29 | ||
| US14/040,722 US9071283B2 (en) | 2013-04-29 | 2013-09-29 | Method for controlling a modulation index of a near field communication device with aid of dynamic calibration, and associated apparatus |
| US14/040,722 | 2013-09-29 |
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| CN104124997A true CN104124997A (en) | 2014-10-29 |
| CN104124997B CN104124997B (en) | 2016-04-27 |
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Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104485983A (en) * | 2014-12-09 | 2015-04-01 | 深圳市汇顶科技股份有限公司 | Touch screen and terminal integrated with NFC (Near Filed Communication) antenna and near filed communication method thereof |
| CN105939166A (en) * | 2015-03-02 | 2016-09-14 | 英特尔Ip公司 | Near field communications (NFC) modulation feedback apparatus for tuned antenna configurations |
| CN107017897A (en) * | 2015-12-14 | 2017-08-04 | 恩智浦有限公司 | Dynamic emission device signal envelope shaping for NFC or RFID device is controlled |
| CN110995367A (en) * | 2019-11-28 | 2020-04-10 | Oppo广东移动通信有限公司 | Debugging method, near field communication device and storage medium |
| CN111682909A (en) * | 2020-06-16 | 2020-09-18 | 易兆微电子(杭州)股份有限公司 | System for transmitting modulation index self-calibration of NFC card reader |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20060065714A1 (en) * | 2004-09-28 | 2006-03-30 | 3M Innovative Properties Company | Passport reader for processing a passport having an RFID element |
| CN1938973A (en) * | 2004-04-01 | 2007-03-28 | 哈里公司 | Modular wide-range transceiver |
| CN101102134A (en) * | 2006-03-24 | 2008-01-09 | 美国博通公司 | Programmable mixed transmitter |
| CN101895939A (en) * | 2009-04-22 | 2010-11-24 | 美国博通公司 | The system of a kind of communication means and process communication signals |
-
2014
- 2014-04-25 CN CN201410169317.8A patent/CN104124997B/en not_active Expired - Fee Related
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1938973A (en) * | 2004-04-01 | 2007-03-28 | 哈里公司 | Modular wide-range transceiver |
| US20060065714A1 (en) * | 2004-09-28 | 2006-03-30 | 3M Innovative Properties Company | Passport reader for processing a passport having an RFID element |
| CN101102134A (en) * | 2006-03-24 | 2008-01-09 | 美国博通公司 | Programmable mixed transmitter |
| CN101895939A (en) * | 2009-04-22 | 2010-11-24 | 美国博通公司 | The system of a kind of communication means and process communication signals |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104485983A (en) * | 2014-12-09 | 2015-04-01 | 深圳市汇顶科技股份有限公司 | Touch screen and terminal integrated with NFC (Near Filed Communication) antenna and near filed communication method thereof |
| US10396430B2 (en) | 2014-12-09 | 2019-08-27 | Shenzhen GOODIX Technology Co., Ltd. | Touch screen integrated with NFC antenna, terminal, and near field communication method therefor |
| KR102056517B1 (en) * | 2014-12-09 | 2019-12-16 | 선전 구딕스 테크놀로지 컴퍼니, 리미티드 | Touch screen integrated with nfc antenna, terminal, and near field communication method therefor |
| CN105939166A (en) * | 2015-03-02 | 2016-09-14 | 英特尔Ip公司 | Near field communications (NFC) modulation feedback apparatus for tuned antenna configurations |
| CN107017897A (en) * | 2015-12-14 | 2017-08-04 | 恩智浦有限公司 | Dynamic emission device signal envelope shaping for NFC or RFID device is controlled |
| CN107017897B (en) * | 2015-12-14 | 2020-09-01 | 恩智浦有限公司 | Dynamic transmitter signal envelope shaping control for NFC or RFID devices |
| CN110995367A (en) * | 2019-11-28 | 2020-04-10 | Oppo广东移动通信有限公司 | Debugging method, near field communication device and storage medium |
| CN111682909A (en) * | 2020-06-16 | 2020-09-18 | 易兆微电子(杭州)股份有限公司 | System for transmitting modulation index self-calibration of NFC card reader |
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