JP2009141693A - Signal sequence generation circuit, signal sequence generating method, signal sequence generation program and communication system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a signal sequence generation circuit which can handle a lot of information without complicating a system configuration or the like, and also can generate a signal sequence excellent in noise resistance. <P>SOLUTION: The signal sequence generation circuit comprises: a multiple M-sequence generating means for generating a plurality of M sequences to be a preferred pair with each other when taken out and watched two by two; a variable delay applying means for applying delay to the plurality of M sequences generated, respectively; and an addition means which applies exclusive OR operation to the plurality of M sequences delayed and outputs signal sequences after the operation. It is preferable herein that the number of M sequences generated by the multiple M-sequence generating means is equal to the maximum number of sequences to be a preferred pair, in a degree thereof, with each other when taken out and watched two by two. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a signal sequence generation circuit, a signal sequence generation method, a signal sequence generation program, and a communication system, and can be applied to, for example, generation of unique individual data (ID) for identification or authentication of an article or an individual. It is.

  In recent years, there has been a need for efficient manufacturing process automation systems and physical distribution systems, and an efficient identification system for articles is required. An efficient identification system is (1) the identification medium added to the article is inexpensive, (2) less susceptible to the surrounding environment (noise, dirt, etc.), and (3) the system for identifying individual data is simple. It can be realized by having features such as low operating costs.

  The M-sequence is one of pseudo-random sequences and is used for spreading code communication and the like, and is a deterministic signal generated by a shift register, but its statistical property is similar to a true irregular signal. Such M series has already been used as individual data for identification and authentication of articles and individuals (see, for example, Patent Document 1).

As a system for identifying an article or an individual, there is a system using a barcode system or a wireless tag (RFID). For example, when an M-sequence is applied to a system using a wireless tag, there are advantages such as less interference with other wireless tags and access to a plurality of wireless tags at a time.
JP 2004-143806 A

  As a signal used for generating individual data for identification or authentication of an individual, it is required to put a large amount of information and to have a high noise resistance.

  For example, in the case of a bar code system, if the surface on which the bar code is printed becomes dirty and noise is mixed in the signal read from the bar code, it may become impossible to recognize articles or individual items. Even in an RFID system, not only when there is a lot of electromagnetic noise, it is often possible that the radio wave signal is disturbed due to reflection or absorption by the surrounding environment and becomes indistinguishable.

  The M-sequence has higher noise resistance than other signal sequences, but even if the M-sequence is applied, noise may be a problem, and the amount of information that can be put on the M-sequence alone is not sufficient. There is also.

  Incidentally, in a large-scale communication system represented by a mobile phone, it is possible to construct a system that is relatively resistant to noise, such as increasing the code length, but the system is complicated and requires a great deal of cost for operation.

  Therefore, a signal sequence generation circuit, a signal sequence generation method, and a signal sequence generation program that can generate a large amount of information without complicating the system configuration and that can generate a signal sequence with excellent noise resistance are desired. However, a communication system that applies such a signal sequence generation method is desired.

  The signal sequence generation circuit according to the first aspect of the present invention includes: (1) a plurality of M sequence generation means for generating a plurality of M sequences that are preferred pairs when viewed two by two; and (2) generated Variable delay adding means for adding a delay to each of a plurality of M sequences; and (3) an adding means for performing an exclusive OR operation on the plurality of M sequences to which a delay has been added, and outputting a signal sequence after the calculation. It is provided with.

  Here, it is preferable that the number of M sequences to be subjected to the exclusive OR operation is equal to the maximum number that becomes a preferred pair with each other when two of them are taken out.

  The signal sequence generation method of the second aspect of the present invention includes (0) a plurality of M sequence generation means, a variable delay addition means, and an addition means. (1) The plurality of M sequence generation means takes out two pieces each (2) The variable delay applying means assigns a delay to each of the generated M sequences, and (3) the adding means generates a delay. Is obtained by performing an exclusive OR operation on a plurality of M sequences to which is given, and outputting a signal sequence after the operation.

  A signal sequence generation program according to a third aspect of the present invention comprises: (0) a computer; (1) a plurality of M sequence generation means for generating a plurality of M sequences that are preferred pairs when viewed two by two; (2) Variable delay adding means for adding a delay to each of a plurality of generated M sequences, and (3) a signal sequence after the operation by performing an exclusive OR operation on the plurality of M sequences to which a delay has been added. It is made to function as the addition means which outputs.

  A communication system according to a fourth aspect of the present invention is characterized in that the individual data generated by the signal sequence generation circuit is used as an ID using the signal sequence generation circuit according to the first aspect of the present invention and communication means.

  Here, it is preferable to use at least one of a barcode and RFID as the communication means.

  The communication system according to the fifth aspect of the present invention uses the wireless tag, the signal sequence generation circuit according to the first aspect of the present invention, and communication means using RFID, and uses the delay data used in the signal sequence generation circuit as an ID. It is characterized by that.

  According to the present invention, a large amount of information can be put on without complicating the system configuration and the like, and a signal sequence having excellent noise resistance can be generated.

(A) Main Embodiment Hereinafter, an embodiment in which a signal sequence generation circuit, a signal sequence generation method, and a signal sequence generation program according to the present invention are applied to an individual data writing device of a wireless tag will be described in detail with reference to the drawings. To do.

(A-1) Configuration of Embodiment FIG. 1 is a block diagram showing a configuration of a wireless tag individual data writing device, and FIG. 2 is a block diagram showing a configuration of a signal sequence generation circuit according to the embodiment. . In FIG. 1, an individual data writing device 1 for a wireless tag includes a management number / delay data conversion unit 2, a signal sequence generation circuit 3, an individual data writing unit 4, a data association storage unit 5, and The control unit 6 is included.

  The management number / delay data conversion unit 2 uses the management number given from the control unit 6 when a blank wireless tag in which individual data is not stored becomes a new write target. This is converted to R0 to Rr and given to the signal sequence generation circuit 3.

  The signal sequence generation circuit 3 may be configured as hardware, or may be configured as software in which functions are realized by the CPU executing a signal sequence generation program. Even if it is realized in FIG. 2, it has a detailed configuration as shown in FIG. The detailed configuration will be described later. The signal series generation circuit 3 generates individual data determined by a detailed configuration to be described later and a delay data group given from the management number / delay data converter 2.

  For example, the individual data writing unit 4 firstly stores a blank wireless tag for each lot, or draws out one wireless tag from the first storage unit and sets it at a writing position. A feeding mechanism unit, a writing execution unit that writes the individual data output from the signal series generation circuit 3 to a blank wireless tag set at the writing position, a second storage unit that stores the wireless tag in which the individual data is written, The wireless tag in which the individual data is written is provided with a moving mechanism unit for moving the wireless tag from the writing position to the second storage unit, and the individual data is written in the blank wireless tag.

  The data association storage unit 5 stores the delay data group (or management number) and the generated individual data in association with each other. The stored association data is used for identification or authentication by a data processing system that processes data from a wireless tag, such as a manufacturing process automation system or a distribution system. Note that the system may use the generated individual data as an ID, or may use a delay data group (or management number) as an ID.

  The control unit 6 controls the entire individual data writing device 1 so as to write individual data to a blank wireless tag as described above.

  As shown in FIG. 2, the signal sequence generation circuit 3 of the embodiment includes M sequences from r + 1 M sequence generation units 10-0 to 10-r and all M sequence generation units 10-0 to 10-r. And an exclusive OR circuit 11 which is an adding means for taking the exclusive OR.

  Each of the M-sequence generation units 10-0 to 10-r includes an M-sequence generation body 20-0 to 20-r that is a plurality of M-sequence generation units, and variable delay units 21-0 to 21- that are variable delay addition units. r.

The M-sequence generation bodies 20-0 to 20-r generate M-sequences according to characteristic polynomials f ₀ (x) to f _r (x) having different orders n, and n-stage shift registers SR0 to SRr and , Has a well-known configuration of one or a plurality of exclusive OR circuits ExOR01 to ExORr1 that take an exclusive OR of the output of the stage determined by the characteristic polynomial.

  In the case of this embodiment, the r + 1 M sequences generated by the M sequence generation bodies 20-0 to 20-r are all in a preferred pair (preferred pair) relationship. Here, for the M series, a pair of M series in which the maximum value of the cross-correlation function with the M series having the same order and different characteristic polynomial is minimized is called a preferred pair. The preferred pair is described in, for example, Document A “D.V. Survate and MB Pursley,“ Crosslation Properties of Pseudorandom and Related Sequences ”, PROC. IEEE, Vol. 68, No. 5, pp. 59. 619, 1980. ”.

  Each of the variable delay devices 21-0 to 21-r delays the M sequence generated by the corresponding M sequence generation main body 20-0 to 20-r by the instructed amount and supplies the delayed delay to the exclusive OR circuit 11. It is. The delay amounts in the variable delay devices 21-0 to 21-r are not necessarily the same, and the combination of these delay amounts is one parameter that defines the uniqueness of the individual data generated by the signal sequence generation circuit 3. .

In the case of this embodiment, each of the variable delay devices 21-0 to 21-r generates a corresponding M sequence so that an arbitrary delay amount shorter than the M sequence period 2 ⁿ −1 can be provided with a simple configuration. Exclusively the outputs of the multiplier groups D0 to Dr that multiply the values of the respective stages of the shift registers SR0 to SRr in the main bodies 20-0 to 20-r by the set values and the outputs of the corresponding multiplier groups D0 to Dr It consists of exclusive OR circuits ExOR02 to ExORr2 that take a logical sum.

The n pieces of data set in the multiplier groups D0 to Dr are delay data R0 to Rr given from the management number / delay data converter 2. For example, delay data R0 {r _0,0 ,..., R _{0, n−1} } is set in the multiplier group D0.

(A-2) Method for Obtaining Delayed M-sequence Next, the fact that the variable delay devices 21-0 to 21-r can be realized by the arithmetic configuration as shown in FIG. This will be described using a delayer model.

If an M-sequence is given an initial state of the n-stage shift register SR, all subsequent states are determined. Therefore, the M-sequence x ^d delayed by an arbitrary delay amount d is determined at each stage of the shift register SR. It can be seen that the content x ₀ ,..., X _n−1 is given by the linear combination represented by the expression (1).

x ^d = r ₀ x ₀ + r ₁ x ₁ + r ₂ x ₂ +... + r _n−1 x _n−1 (1)
The coefficient r _i (i is 0 to (n−1)) is “0” or “1”. If the coefficient r _i is known, it can be determined which stage of the shift register SR should be added.

The delay amount d can take a value in a range shorter than one cycle 2 ⁿ⁻¹ of the M sequence, and can take a value smaller than the number n of stages of the shift register SR, or can take a number n or more.

When the delay amount d is smaller than the number n of stages of the shift register SR, the delayed M series can be extracted from the stage j corresponding to the delay amount d of the shift register SR. In this case, only the coefficients r _j for content x _j of that stage j is "1", all of the coefficients for the contents of the other stages may be "0".

Consider a case where the delay amount d is greater than or equal to the number n of stages of the shift register SR. When the delayed M sequence ^xd is divided by the characteristic polynomial f (x) related to the M sequence generation body, the following equation (2) is established. In equation (2), Q (x) is a quotient, and R (x) is a remainder polynomial.

x ^d = Q (x) f (x) + R (x) (2)
Pay attention to the right side of equation (2). Here, the degree of the remainder polynomial R (x) is smaller than n, and the degree part entrusted to the remainder polynomial R (x) in Q (x) f (x) is zero. Here, considering the same order as the right side of equation (1), equation (2) can be written as equation (3).

x ^d = R (x) (3)
From the comparison between the equations (1) and (3), the coefficient of the remainder polynomial R (x) becomes r _{0 to} r _n−1 for forming the M sequence x ^d delayed by the delay amount d. Yes. That is, in order to form the M-sequence x ^d which is delayed by the time delay d may be taken out of the coefficients of x ^d a characteristic polynomial f (x) obtained by dividing obtained remainder polynomial R (x).

(A-3) Operation of Individual Data Writing Device for Wireless Tag Next, the operation of the individual data writing device for the wireless tag will be described.

  When a new blank wireless tag is to be written, the control unit 6 sets initial values in all the shift registers SR0 to SRr of the signal series generation circuit 3 and manages the management number related to the wireless tag to be written. This is given to the number / delay data converter 2. The management number / delay data conversion unit 2 converts the management number into the delay data groups R0 to Rr and sets them in the multiplier groups D0 to Dr of the signal sequence generation circuit 3.

  When such initialization processing ends, the control unit 6 causes the signal sequence generation circuit 3 to start an operation based on the clock.

The M sequence generation body 20-0 of the M sequence generation unit 10-0 rewrites the contents of the stage of the shift register SR0 for each clock. The multiplier group D0 of the variable delay device 21-0 multiplies the contents of the stage of the shift register SR0 by the set value of the delay data group R0, and the multiplication result is added by the exclusive OR circuit ExOR02 ( And is output as an M series a ₀ (j + d ₀ ) delayed by a delay amount corresponding to the value of the delay data group R0.

The other M sequence generation units 10-1 to 10-r operate in the same manner, and output delayed M sequences a ₁ (j + d ₁ ) to a _r (j + d _r ).

The exclusive OR circuit 11 adds (exclusive OR) the delayed M sequences a ₀ (j + d ₀ ) to a _r (j + d _r ) from all the M sequence generators 10-0 to 10 -r. Output as individual data.

  The output individual data is written to the wireless tag to be written by the individual data writing unit 4. Further, the data association storage unit 5 stores the delay data group (or management number) and the generated individual data in association with each other.

(A-4) Concept of signal generation As for the M sequence, the M sequence pair having the same order and the minimum value of the cross-correlation function with the M sequence having different characteristic polynomials is as described above. , Called the Preferred Pair. It has been found that the maximum value H of the number of M-sequences that are mutually preferred pairs is as shown in FIG. However, it is not shown which pair is specifically a preferred pair.

  In this embodiment, attention is paid to the fact that sequences generated by combining M sequences that are preferred pairs with each other are sequences having a small correlation with each other.

In FIG. 4, suppose that the largest set (the number of elements is H) of preferred pairs that are mutually preferred pairs is used for signal generation, a larger amount of information can be transmitted as n × H is larger. Assuming that there are r combinations whose maximum value of aggregate elements that are mutually preferred pairs is H, the total amount of information that can be sent is r × 2 ^{n × H.}

  In this embodiment, unlike the Gold sequence using two M sequences and the Kasami sequence using three M sequences, all or most of the H M sequences that are preferred pairs with each other are used. This is a method for generating a signal sequence with less interference, in which the type of information to be inserted is increased by adding after delaying.

  According to FIG. 4, the larger the product of the order n of the M sequence and the maximum value H of the number of preferred pairs, the larger the information that can be loaded. Explain the law.

  As for the degree 7, since it is known that the total number of characteristic polynomials is 18, as a result of selecting 6 (maximum value H) from these and searching for a combination in which any pair of them is a preferred pair, We found 18 sets of M series shown in FIG.

In addition, the value which prescribes | regulates the characteristic polynomial in FIG. 5 is octal display, and represents the following. The order is not 7, but the case of characteristic polynomial f (x) = 1 + x ⁴ + x ⁵ + x ⁶ + x ⁸ is taken as an example. In this case, when each power coefficient is represented by 0 and 1, and only the coefficient is extracted and represented, the characteristic polynomial f (x) can be represented as f (x) = 1000011101 (binary number). When such a binary display is displayed in octal, the characteristic polynomial f (x) can be expressed as f (x) = 435 (octal number). FIG. 5 applies such octal display.

2 is selected to form the signal sequence generation circuit 3 of FIG. 2 so that one of the 18 sets of FIG. 5 is selected and the six characteristic polynomials f ₀ (x) to f ₅ (x) of the set are selected. (= H = 6) seventh-order M-sequence generators 10-0 to 10-r are formed. The delay data groups R0 to Rr are also obtained by using the selected set of six characteristic polynomials f ₀ (x) to f ₅ (x).

Signal generation when the 7th order M-sequence is used is expressed by the following equation (4) because the number of M-sequence generation units 10-0 to 10-r is six.

  For the 11th order M-sequence, it is known that the maximum number H of aggregate elements that become a preferred pair is 4 in any case. The total number of eleventh-order characteristic polynomials is 176, and there are a total of 336 combinations as shown in FIG. 6 to FIG. I found. The characteristic polynomial in FIGS. 6 to 13 is octal display.

1 is selected, and the signal sequence generation circuit 3 of FIG. 1 is formed so as to follow the four characteristic polynomials f ₀ (x) to f ₃ (x) of the one set. R + 1 (= H = 4) eleventh-order M-sequence generation units 10-0 to 10-r are formed. The delay data groups R0 to Rr are also obtained by using the selected set of four characteristic polynomials f ₀ (x) to f ₃ (x).

When the 11th order M-sequence is used, the number of M-sequence generation units 10-0 to 10-r is four, so that the signal is generated as shown in Equation (5).

(A-5) Effect of Embodiment The above embodiment uses H sequences that are easy to generate, and are H-preferred pairs (for example, H = 6 in the 7th order, H = 6 in the 11th order, H = 4) After adding a delay to each of the M sequences and adding them by exclusive OR to obtain an output signal sequence (individual data), a large amount of information with little cross-correlation and little interference A signal sequence with good noise resistance can be generated.

The amount of information to be loaded, for example, when using a 7-order M sequence (sequence length 127), 18 × ^{2 42} pieces, in the case of 11-order (sequence length 2047), becomes 336 × ^{2 44} pieces of information amount, An extremely large amount of information can be placed.

  Moreover, since this sequence has a small correlation with other sequences having different information and excellent noise resistance characteristics, it can be used for an article or individual identification or authentication system using a wireless tag as in the above embodiment. When applied, it can produce extremely large effects.

  Hereinafter, the results of a plurality of simulations confirming the effects of the above embodiment will be described.

FIG. 14A shows the autocorrelation function φ _kk (i) of the signal sequence C _k (j) generated by giving a delay as shown in FIG. 14B to each of the 7th order M sequences. Yes. The autocorrelation function φ _kk (0) at the origin i = 0 was the largest at 127, and the next largest autocorrelation function φ _kk (i) was 23 when i = 2. Thus, it can be seen that the individual data can be recognized by obtaining the correlation between the individual data stored in the wireless tag and the same series.

FIG. 15A shows the mutual relationship between two signal sequences C _k1 (j) and C _k2 (j) generated by giving a delay as shown in FIG. The correlation function φ ₁₂ (i) is shown. The cross-correlation function φ ₁₂ (i) at i = 123 is the largest at 31, and this maximum value is sufficiently smaller than the maximum value 127 of the autocorrelation function φ _kk (i).

That is, it can be seen that the two signal sequences C _k1 (j) and C _k2 (j) can be extracted by the cross-correlation process and do not interfere with other signal sequences.

FIG. 16A shows a signal sequence C _k (j) generated by giving a delay as shown in FIG. 16B to each of the 7th-order M sequences, and 70 to the signal sequence C _k (j). The cross-correlation function φ ₁₂ (i) with the noise mixed with% noise is shown. The cross-correlation function φ ₁₂ (0) at the origin i = 0 was the largest at 41, and the next largest cross-correlation function φ ₁₂ (i) was 25 when i = 78. Thus, it can be seen that the seventh order can withstand at least 70% noise.

FIG. 17 shows a cross-correlation function φ ₁₂ (i) of a signal obtained by adding eight different signal sequences C _k1 (j) to C _k8 (j) and one of eight signal sequences C _k1 (j). ). The cross-correlation function φ ₁₂ (0) at the origin i = 0 was the largest at 15, and the next largest cross-correlation function φ ₁₂ (i) was 11 when i = 41. As a result, it can be seen that in the case of the seventh order, simultaneous reading of the eight wireless tags can be performed to some extent. Incidentally, it is known from other simulations that in the case of the 7th order, it can sufficiently cope with simultaneous reading of five wireless tags.

FIG. 18A shows the autocorrelation function φ _kk (i) of the signal sequence C _k (j) generated by giving a delay as shown in FIG. 18B to each of the 11th order M sequences. Yes. The autocorrelation function φ _kk (0) at the origin i = 0 was the largest at 2047, and the next largest autocorrelation function φ _kk (i) was 145 when i = 153. Thus, it can be seen that the individual data can be recognized by obtaining the correlation between the individual data stored in the wireless tag and the same series.

FIG. 19A shows the mutual relationship between two signal sequences C _k1 (j) and C _k2 (j) generated by giving a delay as shown in FIG. 19B to each of the eleventh two M sequences. The correlation function φ ₁₂ (i) is shown. The cross-correlation function φ ₁₂ (i) at i = 1120 is the largest at 159, and this maximum value is sufficiently smaller than the maximum value 2047 of the autocorrelation function φ _kk (i).

That is, even in the 11th order, the two signal sequences C _k1 (j) and C _k2 (j) can be extracted by the cross-correlation process and do not interfere with other signal sequences.

20A shows a signal sequence C _k (j) generated by giving a delay as shown in FIG. 20B to each of the 11th-order M sequences, and 90 to the signal sequence C _k (j). The cross-correlation function φ ₁₂ (i) with the noise mixed with% noise is shown. The cross-correlation function φ ₁₂ (0) at the origin i = 0 was the largest at 285, and the next largest cross-correlation function φ ₁₂ (i) was 157 when i = 1203. This shows that the 11th order can withstand at least 90% of noise.

FIG. 21 shows a cross-correlation function φ ₁₂ (i) of a signal obtained by adding 60 different signal sequences C _k1 (j) to C _k60 (j) and one signal sequence C _k1 (j) out of 60. ). The cross-correlation function φ ₁₂ (0) at the origin i = 0 was the largest as 40, and the next largest cross-correlation function φ ₁₂ (i) was 20 when i = 1966. As a result, in the 11th order, it can be understood that about 60 wireless tags can be read simultaneously.

(B) Other Embodiments In the above description, the signal sequence generation circuit of the present invention is applied to an individual data writing device for a wireless tag. However, the use of the signal sequence generation circuit of the present invention is limited to this. It is not something. For example, the signal sequence generation circuit of the present invention can be applied to a device on the authentication side. For example, authentication or identification is performed by inputting a password or ID consisting of a delay data group from a keyboard or the like, and collating a signal sequence generated from the input delay data group with a signal sequence read from a wireless tag. Anyway. Further, for example, a signal sequence to be described as a barcode may be generated by the signal sequence generation circuit of the present invention.

  In the above-described embodiment, the configuration in which the generated M sequence is delayed includes the multiplier group and the exclusive OR. However, other variable delay configurations may be applied. For example, if the range of the delay amount is narrow, a configuration in which a delay shift register and an output of an arbitrary stage of the delay shift register are taken out may be a variable delay configuration.

  Further, in the above-described embodiment, the maximum number (H) of M sequences that are preferred pairs with each other is generated and added with a delay, but the maximum number (H) is generated. The number of occurrences may be reduced, and the number of occurrences may be variable.

  The signal sequence generation circuit of the present invention can be applied to a communication system, and the communication system to which the signal sequence generation circuit of the present invention is applied becomes the communication system of the present invention.

  As a first embodiment of the communication system of the present invention, there is a signal sequence generation circuit of the present invention and a communication means using an individual data generated by the signal sequence generation circuit as an ID. As the communication means, it is preferable to use a bar code or RFID. Specifically, a two-dimensional bar code, a three-dimensional bar code, an RFID reader / writer using radio waves, or the like may be used.

When using a barcode, the individual data C _k (j) generated by the signal sequence generation circuit is printed on a label or the like as a barcode, and then the individual data is read from the barcode using a barcode reader when necessary. . Identification means is provided in advance in a reader or a personal computer (PC) connected from the reader to calculate and identify the cross-correlation coefficient of each signal, and individual data read by the reader is identified using the identification means. .

When using RFID, the individual data C _k (j) generated by the signal generation circuit is input to the wireless tag using the RFID reader / writer, and thereafter, when necessary, the individual data is received from the wireless tag using the RFID reader / writer. read. Identification means is provided in advance in a reader or a personal computer (PC) connected from the reader to calculate and identify the cross-correlation coefficient of each signal, and individual data read by the reader is identified using the identification means. .

  As a second embodiment of the communication system of the present invention, a wireless tag, a signal sequence generation circuit of the present invention, and delay means used in the signal sequence generation circuit are used as IDs, and communication means using RFID is used. There is something. A signal series generation circuit is provided in advance in a wireless tag (RFID tag), and separate delay data is input to each wireless tag. In each wireless tag, individual data is generated from the given delay data using a signal series generation circuit, and thereafter, when necessary, the individual data is read from the wireless tag using an RFID reader / writer. An identification means is provided in advance in a reader or a personal computer (PC) connected from the reader to calculate and identify the cross-correlation coefficient of each signal, and the individual data read by the reader is delayed using the identification means. To identify individual wireless tags.

  The radio wave of the RFID used in the present invention is not particularly limited, but the frequency ranges widely from LF band of 100 KHz to 3 MHz, HF band of 3 MHz to 30 MHz, VHF band of 30 MHz to 300 MHz, UHF band of 300 MHz to 3 GHz. Can be used.

  The wireless tag used in the present invention is not particularly limited, but a tag that has a built-in battery and transmits radio waves by itself or a tag that exchanges data using external radio waves can be used. Furthermore, the thing using electromagnetic induction, the thing using a radiated electromagnetic field, etc. can be used. Examples of the electric circuit (antenna circuit) in the wireless tag include a coil shape and a dipole type.

It is a block diagram which shows the structure of the separate data writing apparatus of a radio | wireless tag to which the signal series generation circuit which concerns on embodiment is applied. It is a block diagram which shows the structure of the signal series generation circuit which concerns on embodiment. It is a block diagram which shows the model of the M series production | generation main body and variable delay device for demonstrating the method to obtain the delayed M series in embodiment. It is explanatory drawing which shows the relationship between the order of M series, and the maximum number of M series which become a preferred pair mutually. It is explanatory drawing which shows the characteristic polynomial of the maximum number of M series which becomes a preferred pair mutually in order 7 M series. It is explanatory drawing (1) which shows the characteristic polynomial of the maximum number of M series which becomes an M series of order 11 and becomes a preferred pair mutually. It is explanatory drawing (2) which shows the characteristic polynomial of the maximum number of M series which becomes a preferred pair mutually in M series of order 11. It is explanatory drawing (3) which shows the characteristic polynomial of the maximum number of M series which becomes a preferred pair mutually in order 11 M series. It is explanatory drawing (4) which shows the characteristic polynomial of the maximum number of M series which becomes a preferred pair mutually in M series of order 11. It is explanatory drawing (5) which shows the characteristic polynomial of the maximum number of M series which becomes a preferred pair mutually in M series of order 11. It is explanatory drawing (6) which shows the characteristic polynomial of the maximum number of M series which becomes a preferred pair mutually in M series of order 11. It is explanatory drawing (7) which shows the characteristic polynomial of the maximum number of M series which becomes a preferred pair mutually in M series of order 11. It is explanatory drawing (8) which shows the characteristic polynomial of the maximum number of M series which becomes an M series of order 11 and becomes a preferred pair mutually. It is explanatory drawing (1) of the effect of the signal sequence generation circuit which concerns on embodiment. It is explanatory drawing (2) of the effect of the signal series generation circuit which concerns on embodiment. It is explanatory drawing (3) of the effect of the signal series generation circuit which concerns on embodiment. It is explanatory drawing (4) of the effect of the signal series generation circuit which concerns on embodiment. It is explanatory drawing (5) of the effect of the signal sequence generation circuit which concerns on embodiment. It is explanatory drawing (6) of the effect of the signal series generation circuit which concerns on embodiment. It is explanatory drawing (7) of the effect of the signal series generation circuit which concerns on embodiment. It is explanatory drawing (8) of the effect of the signal series generation circuit which concerns on embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 3 ... Signal series generation circuit, 10-0 to 10-r ... M series generation part, 11 ... Exclusive OR circuit, 20-0 to 20-r ... M series production | generation main body, 21-0 to 21-r ... Variable Delay device.

Claims (7)

A plurality of M-sequence generating means for generating a plurality of M-sequences that are paired with each other when viewed two by two;
Variable delay providing means for adding a delay to each of the plurality of generated M sequences;
A signal sequence generation circuit comprising: addition means for performing an exclusive OR operation on a plurality of M sequences to which a delay is added and outputting a signal sequence after the operation.   2. The signal sequence according to claim 1, wherein the number of M sequences subjected to the exclusive OR operation is equal to a maximum number that becomes a preferred pair with each other when the two sequences are taken out. Generation circuit. A plurality of M-sequence generating means, a variable delay providing means and an adding means;
The plurality of M-sequence generating means generates a plurality of M-sequences that are preferred pairs when viewed two by two,
The variable delay giving means gives a delay to each of the generated M sequences,
A signal sequence generation method, wherein the adding means performs an exclusive OR operation on a plurality of M sequences to which a delay is added, and outputs a signal sequence after the operation. Computer
A plurality of M-sequence generating means for generating a plurality of M-sequences that are paired with each other when viewed two by two;
Variable delay providing means for adding a delay to each of the plurality of generated M sequences;
A program for generating a signal sequence, wherein an XOR operation is performed on a plurality of M sequences to which a delay is added, and the M series functions as addition means for outputting a signal sequence after the operation. Using the signal sequence generation circuit according to claim 1 and communication means,
A communication system using the individual data generated by the signal sequence generation circuit as an ID.   6. The communication system according to claim 5, wherein at least one of a barcode and an RFID is used as the communication means.   A communication system, wherein a delay tag used in the signal sequence generation circuit is used as an ID using a wireless tag, the signal sequence generation circuit according to claim 1, and communication means using RFID.

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