KR20000057763A - Method for generating complex quasi-orthogonal code and apparatus and method for spreading channel data using the quasi-orthogonal code in cdma communication system - Google Patents

Abstract

PURPOSE: A method for generating quasi-orthogonal code in CDMA communication system, and apparatus and method for expanding channel using the method is provided to increase a channel capacity by using a complex quasi-orthogonal code regardless of a limit of a orthogonal code. CONSTITUTION: A first Walsh orthogonal code generator(2060) receives a Walsh orthogonal code index(k) for a channel allocation and outputs a kth Walsh orthogonal code corresponding to the received Walsh orthogonal code index(k) to a multiplier(2040). A sign code generator(2070) receives a quasi-orthogonal code index(t) and outputs a tth sign code corresponding to the received quasi-orthogonal code index(t) to the multiplier(2040). The multiplier(2040) multiplies the inputted Walsh orthogonal code and the signal code and provides the multiplied signals to multipliers(2050,2052). The multiplier(2050) multiplies an inputted I component input signal(Xi) and a signal inputted from the multiplier(2040) and outputs the multiplied signal to a rotator(2010). The multiplier(2052) multiplies an inputted Q component input signal(Xq) and a signal inputted from the multiplier(2040) and outputs the multiplied signal to a rotator(2010). A second Walsh orthogonal code generator(2065) outputs a corresponding Walsh orthogonal code to an inputted mask index(t).

Description

METHODO FOR GENERATING COMPLEX QUASI-ORTHOGONAL CODE AND APPARATUS AND METHOD FOR SPREADING CHANNEL DATA USING THE QUASI-ORTHOGONAL CODE IN CDMA COMMUNICATION SYSTEM}

The present invention relates to a spreading device and a method of a mobile communication system, and more particularly, to a method for generating a quasi-orthogonal code mask for generating a complex quasi-orthogonal code, and an apparatus and method for spreading and despreading channel data using the same. .

In general, a mobile communication system (hereinafter referred to as a CDMA system) that performs code division is one of methods for increasing capacity, and uses a method of channel separation using orthogonal codes. have. An example of performing channel division by the orthogonal code as described above is the forward link of IS-95 / IS-95A, and it is applied by time alignment on the reverse link. can do. In addition, orthogonal codes are used for the downlink of UMTS to distinguish channels.

Channel division by an orthogonal code in the forward link of the IS-95 / IS-95A is performed as shown in FIG. 1. In FIG. 1, orthogonal codes are denoted by w, and each channel is divided by a pre-assigned orthogonal code. In FIG. 1, w may be a Walsh orthogonal code. The IS-95 / IS-95A forward link uses a convolution code of R = 1/2, performs bi-phase shift keYing modulation, and has a bandwidth of 1.2288 MHz. /(9.6k*2)=64. Accordingly, as shown in FIG. 1, the forward link of the IS-95 / IS-95A can distinguish channels using 64 Walsh orthogonal codes.

When the modulation method is determined as described above and the minimum data rate is determined, the number of available orthogonal codes is determined. However, in future CDMA systems (future code division multiple access system), the number of channels allocated to real users is increased to improve performance. To this end, the next generation CDMA system has a traffic channel, a pilot channel, and a control channel, so that more channels are allocated to subscribers, and the capacity of receiving subscribers is increased.

However, even in the above manner, when the channel usage increases, the number of available orthogonal codes is limited. In this case, even if the channel capacity is increased, there is a limit to the increase in the channel capacity according to the limitation of the number of orthogonal codes that can be used. Therefore, as a method for solving the above problems, a minimum interference (quasi-orthogonal code) that gives a minimum interference (minimum interference) to the orthogonal code, and can also give a minimum interference to a variable data rate (variable data rate) It may be desirable to generate and use.

Accordingly, an object of the present invention is to provide an apparatus and method capable of generating a complex quasi-orthogonal code giving minimal interference to an orthogonal code in a code division multiple access communication system using an orthogonal code.

Another object of the present invention is to generate and apply a complex quasi-orthogonal code for QPSK modulation, thereby providing a correlation between orthogonal codes for length L. An apparatus and method for generating a complex quasi-orthogonal code having:

It is still another object of the present invention to provide an apparatus and method for spreading a channel with a complex quasi-orthogonal code generated using a quasi-orthogonal code mask in a channel spreader of a code division multiple access communication system.

It is still another object of the present invention to provide an apparatus and method for spreading a channel with a complex quasi-orthogonal code generated by using a code and a phase of a quasi-orthogonal code in a channel spreader of a code division multiple access communication system.

It is still another object of the present invention to provide an apparatus and method for increasing channel capacity by generating a quasi-orthogonal code giving minimal interference to an orthogonal code in a code division multiple access communication system using an orthogonal code.

It is still another object of the present invention to provide a method for generating quasi-orthogonal sequences satisfying all conditions of quasi-orthogonal codes in a code division multiple access communication system.

It is still another object of the present invention to provide a heat exchange method for generating quasi-orthogonal sequences satisfying conditions of quasi-orthogonal codes in a code division multiple access communication system.

It is still another object of the present invention to provide quasi-orthogonal codes that satisfy the conditions of quasi-orthogonal codes in a code division multiple access communication system and can be represented by a sign code and a phase code.

Another object of the present invention is to provide an apparatus and method for spreading / despreading a channel signal using a quasi-orthogonal code represented by a sign code and a phase code in a code division multiple access communication system.

Another object of the present invention is to provide a quasi-orthogonal code that satisfies the conditions of a quasi-orthogonal code in a code division multiple access communication system and can be represented by a specific Walsh code used as a sign code and a phase code.

It is still another object of the present invention to provide an apparatus and method for spreading / despreading a channel signal using a quasi-orthogonal code representing a specific Walsh code indicating a sign code and a phase.

1 is a view for explaining a characteristic of distinguishing channels by orthogonal codes in a code division multiple access communication system;

2 is a diagram for explaining a partial correlation characteristic between Walsh orthogonal codes and quasi-orthogonal codes.

3 illustrates a structure of a matrix Q for mask candidates of quasi-orthogonal codes for use in generating complex quasi-orthogonal codes according to an embodiment of the present invention.

4 illustrates a structure of a matrix Q 'for candidates of complex quasi-orthogonal codes generated by operation of mask candidates of quasi-orthogonal codes and Walsh orthogonal codes when generating complex quasi-orthogonal codes according to an embodiment of the present invention. drawing

5 is a flowchart illustrating a process of generating complex quasi-orthogonal codes according to an embodiment of the present invention.

FIG. 6 is a diagram illustrating an example of classifying channels using Walsh orthogonal codes and quasi-orthogonal codes in a spreading apparatus of a code division multiple access communication system according to an exemplary embodiment of the present invention.

7 is a diagram illustrating a configuration of a channel spreader using a complex quasi-orthogonal code in a code division multiple access communication system according to an embodiment of the present invention.

8 is a diagram showing the configuration of a complex quasi-orthogonal code spreading and pien masking unit in FIG.

9 compares a complex representation of a hexadecimal number on a complex plane with a complex representation for sending signals in a real system.

FIG. 10 is a diagram illustrating an example of a configuration of a complex quasi-orthogonal code generator according to a first embodiment of the present invention in FIG. 7. When a quasi-orthogonal mask is output as a hexadecimal value as shown in Table 9, FIG. Drawing showing the structure of the generator,

FIG. 11 is a diagram illustrating an example of a configuration of a complex quasi-orthogonal code generator according to the first embodiment of the present invention in FIG. 7. FIG. A diagram showing the structure of an orthogonal code generator

12 is a diagram showing the configuration of a complex quasi-orthogonal code spreading apparatus according to a second embodiment of the present invention in the complex quasi-orthogonal code spreading and pien masking unit of FIG.

FIG. 13 is a diagram illustrating a configuration of the rotor of FIG. 12.

FIG. 14 is a diagram showing the configuration of another complex quasi-orthogonal code spreading device according to the second embodiment of the present invention in the complex quasi-orthogonal code spreading and pien masking unit of FIG.

FIG. 15 is a view showing the rotor configuration of FIG. 14. FIG.

FIG. 16 is a diagram showing the configuration of an apparatus for despreading a signal transmitted in a spreading device having the configuration as shown in FIG.

FIG. 17 is a view showing the rotor configuration of FIG. 16. FIG.

FIG. 18 is a diagram showing the configuration of an apparatus for despreading a signal transmitted in a spreading device having the configuration as shown in FIG.

FIG. 19 is a diagram illustrating the rotor configuration of FIG. 18. FIG.

20 is a diagram showing the configuration of a complex quasi-orthogonal code spreading device according to a third embodiment of the present invention in the complex quasi-orthogonal code spreading and pien masking unit of FIG.

21 is a diagram showing the configuration of another complex quasi-orthogonal code spreading device according to a third embodiment of the present invention in the complex quasi-orthogonal code spreading and pien masking unit of FIG.

22 is a flowchart illustrating a process of generating a heat substitution function according to another embodiment of the present invention in the process of FIG. 5 generating a quasi-orthogonal code.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

In the following description, specific details for generating quasi-orthogonal codes, lengths of quasi-orthogonal codes, correlation values, etc., are shown to provide a more general understanding of the invention. It will be apparent to one of ordinary skill in the art that the present invention may be readily practiced without these specific details and also by their modifications.

As described above, in the CDMA system using an orthogonal code, a CDMA system is generated by generating a quasi-orthogonal code giving minimal interference to an orthogonal code in a situation where an increase in channel capacity or maximization of a single cell capacity is required. To apply.

In the embodiment of the present invention, it is assumed that the quasi-orthogonal code is a quadratic complex quasi-orthogonal code. In the following description, the quasi-orthogonal code includes the quaternary-complex quasi-orthogonal code and the quaternary-complex quasi-orthogonal code in the form of a sign and a quasi-orthogonal code represented by a sign code and a phase code. do.

Sequences with quasi-orthogonal characteristics can be inferred from sequences such as the Kasami Sequence, Gold Sequence, and Kerdock Sequence. The sequences have one thing in common, which is the property of PN sequences (M sequences) and the sequence of good (or high) sequences of correlation with this sequence. Sequences with these properties can be used to make quasi-orthogonal codes because of their properties. Walsh orthogonal codes can be obtained by appropriate column permutation of PN sequences (M sequences). At this time, when there is a sequence consisting of a sum of a sequence and a Pien sequence as described above, if the sequence is thermally substituted in the same manner as the thermal substitution method of the PN sequences (PN sequences, M sequences), the thermally substituted sequence is Walsh orthogonal. Good correlation with the sign is maintained. That is, since the sequences are equally thermally substituted for two sequences having good correlation characteristics, the correlation in the entire length of the sequences does not change and still maintain a good correlation. In this case, the sum of the two sequences except for the PN sequence may have one other candidate sequence of the mask of the quasi-orthogonal code, which will be described below. Basically satisfied.

In the present invention, a process of making a complex quasi-orthogonal code using a curdiction sequence (generally Family A Sequence) in the sequence having the above characteristics will be described in detail.

The complex quasi-orthogonal code should satisfy the following Equation 1-Equation 3.

In addition, the complex quasi-orthogonal code preferably satisfies the following <Equation 4> as much as possible.

Where i = 0,1,2, ---, M-1 to be.

In Equation 1 to Equation 4, W _k (t) denotes a k-th sequence of Walsh orthogonal codes having a length of N (1 ≦ k ≦ N), and S _i (t) represents N in length. Denotes the i-th complex quasi-orthogonal code (1 ≦ i ≦ X). X is a number of quasi-orthogonal codes satisfying condition 1-condition 3 and partially satisfying Equation 4. Condition 1 of Equation 1 is i-th orthogonal code W _k (t) (1≤k≤N, 1≤t≤N) and quasi-orthogonal code S _i (t) (1≤i≤N, 1 ≤ t ≤ N) means that the total correlation should not exceed θ _Nmin . In addition, condition 2 of Equation 2 means that the total correlation between the i-th line and the i-th line of the quasi-orthogonal code should not exceed θ _min (N), and the condition of Equation 3 above. 3 is a partial correlation between the parts of each length N / M equal to M equal to the length N of the i-th line of the quasi-orthogonal code and the k-th line of the orthogonal code. Should not exceed. Where M = 2 ^m and m = 0, 1, ..., log ₂ N.

Condition 1 of Equation 1 indicates a full correlation property of Walsh orthogonal codes and complex quasi-orthogonal codes, and θ _min (N) = As a result, it means the minimum correlation value that a complex quasi-orthogonal sequence can have as an absolute correlation value with Walsh orthogonal code in theory. Where N is the length of the sign. In addition, condition 2 of Equation 2 represents a condition for a full correlation characteristic of the complex quasi-orthogonal codes. In addition, condition 3 of Equation 3 represents a partial correlation characteristic between Walsh orthogonal codes and complex quasi-orthogonal codes, and condition 4 of Equation 4 indicates partial correlation between complex quasi-orthogonal codes. (partial correlation) characteristics.

FIG. 2 illustrates a case where a partial correlation between the complex quasi-orthogonal code and Walsh orthogonal code under <Condition 3> is taken. M is expressed as 2 ^a (0 ≦ ^a ≦ log ₂ N), and the partial correlation is to transmit the N / M portion of the orthogonal code as the data rate increases when supporting the data service. It is a condition that satisfies characteristics. For example, if N = 256 The values are shown in Table 1 below. Condition 4 means partial correlation between quasi-orthogonal codes, The value is equal to the correlation characteristic value in condition 3 above.

The results in Table 1 above can generally be extended. For example, when N = 1024 and M = 2, the partial correlation between Walsh orthogonal codes and quasi-orthogonal codes is calculated as half of the total length (here 512). In other words, the limit of partial correlation for this is the full correlation bound of length 512. Is the same as Table 2 below shows the minimum correlation value with the length N. An example of the relationship is shown.

Sequences satisfying condition 1 and condition 2 include a Kasami sequence, a Gold sequence, a Kerdock sequence, and the like. That is, a sequence family having a good cross correlation property includes the Kasami sequence family, the Gold sequence family, and the Kardock sequence family (the family of the sequences). Kerdock sequence family, and the full correlation property of the family of the sequences is well known.

However, research on the sequence satisfying the condition 3 is not active. However, condition 3 is very important in an IS-95B or a future CDMA system supporting variable data rates.

In the correlation property of the sequences, the sequences are odd powers of length 2. The correlation for to be. Thus, the sequences are odd powers of length 2 The correlation is not the best. Where L is the length of the sequence.

In the present invention, the odd power of length 2 is generated by generating a sequence represented by a quadratic complex number. Correlation with And a method and apparatus for satisfying the above conditions. In the embodiment of the present invention, it is assumed that a read dog sequence is used to generate the complex quasi-orthogonal code.

5 is a flowchart illustrating a process of generating a complex quasi-orthogonal code for use in a spreading apparatus of a code division multiple access communication system according to an embodiment of the present invention. The Walsh orthogonal code is generated by thermally replacing the M sequence.

First, in order to generate a quasi-orthogonal code, in step 511, a specific sequence having excellent overall correlation characteristics with the M sequence and Walsh orthogonal code is generated. In order to generate the complex sequence, in the embodiment of the present invention, a family A representing a set of the codec codes generated from the Kerdock code expressed in hexadecimal is used. At this time, homomorphism corresponds to a complex set of multiplication operations in a ternary set of modulo-4 (mod 4) operations. This exists. That is, the hexadecimal number {0,1,2,3} becomes {1, j, -1, -j} when expressed in complex form. Therefore, we will first generate the sequence and then transform each by the quasi-morphism.

The binary M-sequence s (t) may be expressed as shown in Equation 5 using a trace function.

only, Is Is a primitive polynomial of Is The root of the primitive element.

Function values of the binary expression have values of 0 and 1, and in a similar manner to the above, a sequence represented by a hexadecimal number can be generated using a trace function.

First, the length in step 511 of FIG. M-order binary primitive polynomial to obtain an orthogonal code sequence Select. The binary primitive polynomial Is a characteristic polynomial that has a coefficient of hexadecimal by Hensel Lift as in Equation 6. Create

Characteristic polynomial Galois ring with Can be configured. And To When is the root of Becomes If you put it, Galoa ring Any element of Is Can be expressed as And the trace function, which is a linear function in the Galoa ring, It is expressed as

Length (N) Sequence To get The above equation is expressed by Equation 7 using a trace expression, and Equation 7 below is a general formula of the code.

In Equation 7 above Is equivalent to 2 times the binary m-sequence taken as mod 4. In the present invention, this sequence portion will be referred to as M-sequence. At this time, 0 or By inserting 0 and inserting 0 into the first column, you can get the M-sequence. Therefore, in step 511, each For length Sequence M-sequence doubled with binary m-sequence Create a (code creation process)

Thereafter, in step 513, a thermal substitution function σ is generated, which transforms the M sequence by Walsh orthogonal code conversion. In this case, the heat substitution function of the M-sequence is applied to the specific sequence to generate a mask for generating a quasi-orthogonal code. That is, in step 513 This is called, When And. Using this, we define the column permutation function σ as follows: Define thermal substitution for)

Now the length Sequence of Equation 7 Insert 0 at the beginning of on By substituting, satisfying condition 1 and condition 2 simultaneously Dog length A complex sequence can be generated. Thus, the above About, When the sequence is as shown in <Equation 7> It is expressed as. Where above Is a function of a specific sequence, which can be expressed by Equation 8 below.

here , Assume

Subsequently, in step 515, a matrix Q (matrix Q) as shown in FIG. 3 is generated using the sequences of the completed set K of Equation (8). The rows of the matrix are (2 ^m −1) * 2 ^m and the columns are 2 ^m . That is, in step 515, the 2 ^m −1 sequences generated in step 511 are used. And defined as shown in Figure 5 above: Insert 0 at the beginning of)

Here, the same column permutation as the method used to replace the M-sequence to obtain the Walsh orthogonal code is applied to the matrix Q to satisfy the condition 1 and condition 2 of length 2 ^m ( It will have 2 ^m -1) sequences. Therefore, in step 517, Si (t) of Equation 7 is thermally substituted in the manner obtained in step 513. In other words, in step 517, the column sequence generated in step 515 is thermally permutated by the heat substitution function implemented in step 513. Then, in step 517, a new sequence is generated, which is as follows.

The sequence ei (t) generated in step 517 is referred to as a quasi orthogonal mask candidate sequence.

Then, in step 519, the quasi-orthogonal code candidate mask sequence is used to combine (exclusively) with the Walsh orthogonal code as shown in FIG. 4 to generate another quasi-orthogonal code candidate sequence that satisfies the conditions 1 and 2. In step 519, quasi-orthogonal code representatives are listed using the sequences generated in step 517 as shown in the following equation. (Create quasi-orthogonal sign candidate)

At this time Denotes a Walsh sequence, which is an orthogonal code, and is assumed to be represented by a symbol of 0 and 1. In the above formula, ei (t) is represented by Equation 7 Is thermally substituted by the thermal substitution formula defined in step 513 above. Therefore, by performing step 519, candidates of (2 ^m −1) * 2 ^m quasi-orthogonal codes may be obtained.

Subsequently, in step 521, among the (2 ^m -1) * 2 ^m sequences which are candidates for the quasi-orthogonal code, the sequences satisfying the condition 3 are selected, and then the mask candidate of the quasi-orthogonal code used here is assigned to the orthogonal code. We choose with mask. That is, when the process as in step 519 is completed, among the mask candidate group Sij (t) finally obtained in step 521, the ones satisfying condition 3 are selected. At this time, the selection method partially takes the lengths of the selected mask candidate and Walsh orthogonal codes to obtain partial correlations, and checks whether the obtained partial correlation is satisfied with the above <Condition 3>. After the partial correlation between the Walsh orthogonal codes and the selected mask candidate is obtained in the same manner as described above, when the <Condition 3> is satisfied, the corresponding mask candidate is selected as the mask.

For example, if the length of orthogonal code is 128, first find the partial correlation with all Walsh orthogonal codes with partial length 64, and then check if the partial correlation between Walsh orthogonal and quasi-orthogonal codes exceeds 8 . If the partial correlation does not exceed 8, the mask candidate used to generate the quasi-orthogonal code candidate is not selected as a mask, and if it is satisfied, the Walsh orthogonal code for the partial length 32 and the quasi-orthogonal code are again selected. Find the partial correlation between orthogonal codes. The partial correlation value at this time Check if it exceeds, and if not, do not select it as a mask, and once again, do the same for the next length again. After performing the above operation up to a partial length of 4, the mask candidates having passed the above conditions are selected as candidate masks of quasi-orthogonal codes satisfying the above <condition 1>-<condition 3>.

A process of generating a quasi-orthogonal code candidate sequence by the process as shown in FIG. 5 will now be described in detail.

Where the binary primitive polynomial Suppose you use Where the binary primitive polynomial When the Henschel lift with Equation 6 above, the characteristic polynomial Becomes In summary, Becomes

Accordingly, in step 511, the root of g (x) is obtained to obtain specific sequences. Shall be. In other words, to be. First of all, for convenience Is obtained as follows.

At this time, when, Obtained as follows.

when t = 0,

when t = 1,

when t = 2,

when t = 3,

when t = 4,

when t = 5,

when t = 6,

Also when, If you get, when t = 0 when t = 1 , when t = 2 , when t = 3, when t = 4 , when t = 5 , when t = 6 Because of, Is the same as the result of shifting the sequence once.

Therefore, 3221211 and the sequence of which the sequence was shifted from the sequence can be obtained, and the sequence shifted i times is referred to as Si. In addition, the m-sequence 10010011 can be obtained.

At this time, in step 513 having the 1001011 as the m-sequence the equation The thermal substitution function for converting the m-sequence into Walsh orthogonal code is obtained by Here, the equation σ (t) means converting the m-sequence into a decimal number by combining three consecutive terms. In other words, the first 3 terms is 100, which translates into decimal, which is 4, the second 3 terms is 001, which translates into decimal, becomes 1, and the third 3 is 010, which translates into decimal, which becomes 2, The fourth term is 101, which translates into 5 as a decimal number, the fifth term is 011, which translates into 3 as a decimal number, and the sixth term is 111, which translates into decimal, which is 7, and the seventh Clause 3 is 110, which translates into decimal to 6 Equation By using the following results can be obtained.

when t = 0,

when t = 1,

when t = 2,

when t = 3,

when t = 4,

when t = 5,

when t = 6,

Therefore, the heat substitution function obtained as described above is as shown in Table 3a.

In step 515, 0 is added to the beginning of all the sequences obtained in step 511. Looking at the expression representing di (t) by Si (t),

When i = 0, i.e., d0 (t) is determined in step 511. Is a sequence of 0 added to the beginning of the obtained sequence S0 (t). That is, as obtained in step 511, S0 (0) = 3, S0 (1) = 2, S0 (2) = 2, S0 (3) = 1, S0 (4) = 2, S0 (5) = 1, When S0 (6) = 1, when d0 (t) is obtained, d0 (0) representing the first bit is always 0, and d0 (7) in d0 (1) are shown in Table 3b below.

In addition, when i = 1, that is, d0 (t) is determined in step 511. Is a sequence of 0 added to the beginning of the obtained sequence S1 (t). That is, as obtained in step 511, S1 (0) = 2, S1 (1) = 2, S1 (2) = 1, S1 (3) = 2, S1 (4) = 1, S1 (5) = 1, When d1 (t) is obtained when S1 (6) = 3, d0 (0) representing the first bit is always 0, and d (7) in d (1) is shown in Table 3c below.

In step 517, the sequence of thermal shifting the sequence is thermally replaced by the thermal substitution function as described above. First, the sequence of thermal shifting the sequence is as shown in Table 3d.

In Table 3d, c1 represents the first column, c2 represents the second column, and ci represents the I-th column. At this time, if the hexadecimal strings shown in Table 3d are thermally substituted by the heat substitution function obtained in step 513, they are as shown in Table 3e.

Therefore, when the sequences obtained by thermally shifting the sequences by the thermal substitution function are obtained, zeros are added to each sequence to make a sequence of length 8 as shown in Table 3f. Become a candidate group of quasi-orthogonal code mask functions.

The sequences of quasi-orthogonal codes generated through the process as shown in FIG. 5 are mask functions. Determined by That is, a quasi-orthogonal code generated from a mask function If <Condition 1>, <Condition 2>, and <Condition 3> are satisfied, Complex quasi-orthogonal codes Therefore, a mask satisfying the above <Condition 1>, <Condition 2>, and <Condition 3> If present, Complex quasi-orthogonal codes Table 4 below shows the number of the above complex quasi-orthogonal codes according to the m-sequence. Table 5 shows the mask function of the complex quasi-orthogonal code sequence for m = 6 Indicates. <Table 6>-<Table 8> are mask functions of complex quasi-orthogonal code sequences for m = 6, m = 7, m = 8 and m = 9, respectively, Indicates. Where 0 is 1 and 1 is , 2 is -1, 3 is Indicates.

As described above, when more orthogonal codes are required in the state of using Walsh orthogonal codes, the channel capacity can be increased by using a quasi-orthogonal code as in the embodiment of the present invention. In this case, minimal interference with the Walsh orthogonal code is provided and a fixed correlation value is provided. For example, if the correlation value between quasi-orthogonal code and Walsh orthogonal code is N = 64, it has only 8 or -8. Also, N = 256 and its partial correlation (while length N = 64) has only 8 or -8. This means that the amount of predicted interference can be known accurately, and it can be seen that it has a fairly good characteristic.

Thus length 2^msign In order to obtain a complex quasi-orthogonal sequence, as we can see in the above process, we first choose the m-order characteristic polynomial f (X), whose length is 128 = 2⁷In order to obtain the complex quasi-orthogonal sequence, we first select the 7th order polynomial. In this case, in order to obtain a sequence of length 128, the characteristic polynomial should be a primitive polynomial, and there are 18 seventh primitive polynomials. Therefore, Table 9 below shows the mask having the highest correlation property among the mask functions among the mask functions of all complex quasi-orthogonal sequences of length 128 satisfying the three correlation conditions according to the eighth order primitive polynomials. Indicates. In addition, the results for Condition 4 are also shown in the following tables. Where e1 + e2 is the partial correlation between the first mask and the second mask, and the numerical value shown next indicates the length of the part where the first mask and the second mask satisfy the above conditions, that is, the < In Table 9, e1 + e2: 64,128 means that the condition 4 is satisfied only for the partial lengths 64 and 128 in the partial correlation between the quasi-orthogonal codes generated by the e1 mask and the e2 mask, respectively. In addition, e1 + e3: 32, 64, 128 means that the above <Condition 4> is satisfied only for the partial lengths 32, 64 and 128 in the partial correlation between the quasi-orthogonal codes generated by the e1 mask and the e2 mask, respectively. Accordingly, it can be seen that the more the type of the partial length satisfying the side value and the partial correlation condition, the better the partial correlation property. As can be seen in the tables below, it can be seen that the partial correlation between quasi-orthogonal sequences varies according to the characteristic polynomial. Therefore, in selecting the above characteristic polynomial, it is preferable to use the characteristic polynomial which generates the quasi-orthogonal sequence with excellent partial correlation between quasi-orthogonal sequences.

As shown in Table 9 above, in using a mask function of a complex quasi-orthogonal array of length 128, for some Walsh sequence W _k instead of the mask functions e _i , complex e _i + W _k is given. Can also be used as a mask for orthogonal sequences. At this time, the complex quasi-orthogonal sequence generated by e _i + W _k is the same as the complex quasi-orthogonal sequence generated by e _i . Thus, there may be ^four branches of 128 × 128 × 128 × 128 = 128 for each characteristic polynomial that can be used as a mask.

In this manner, there are 16 eighth order primitive polynomials, and Table 10 shows all complex criteria of length 256 satisfying the three correlation conditions according to the sixteenth order primitive polynomials. Among the mask functions of the orthogonal sequence, the mask has the best correlation property among the mask functions. Also, similarly to the case of length 128, e _i + W _k is complex quasi-orthogonal to a Walsh sequence W _k instead of the mask functions e _i in using a mask function of a complex quasi-orthogonal sequence of length 256. The complex quasi-orthogonal sequence generated by e _i + W _k is the same as the complex quasi-orthogonal sequence generated by e _i . Therefore, there may be ^four types of branches that can be used as masks in actuality for each characteristic polynomial 256 x 256 x 256 x 256 = 256.

The mask values shown in Table 10 are all expressed in hexadecimal numbers. As described above, when mask values of the hexadecimal numbers shown in Table 10 are represented by complex numbers, 0 represents 1, 1 represents j, 2 represents -1, and 3 represents -j. Therefore, it can be seen that the complex expression is composed of four complex expressions such as 1, j, -1, and -j. However, a complex representation for transmitting a signal in an actual code division multiple access communication system such as IS-95 is composed of four complex representations such as 1 + j, -1 + 1, -1-j, and 1-j.

FIG. 9 is a diagram illustrating a comparison of a complex representation of the hexadecimal number in the complex plane with a complex representation for transmitting a signal in an actual code division multiple access communication system. Therefore, in order to correct the above mask value to the complex expression in the actual system, 0 is transmitted as 1 + j, 1 is transmitted as -1 + j, 2 is transmitted as -1-j, and 3 is 1-. Send to j. The above correspondence is the rotation of the complex representation of the hexadecimal number 1, j, -1, -j in 45 degrees, which can be obtained by multiplying the complex representation of the hexadecimal number by 1 + j. Through the above correspondence, the mask values represented by the hexadecimal numbers are converted into complex expressions of 1 + j, -1 + 1, -1-j, and 1-j, where the real part I and the imaginary part Q are divided and expressed. Can be. <Table 11> and <Table 12> shown below show that the mask values of <Table 10> and <Table 9> were expressed by the hexa value by dividing the real part I and the imaginary part Q as mentioned above. . In particular, <Table 10> and <Table 9> have excellent properties of partial correlation with <condition 4> for the total lengths 256 and 128, respectively.

Such complex quasi-orthogonal codes can be used for links in all CDMA systems that use Walsh orthogonal codes. In the case of using the complex quasi-orthogonal code together with the orthogonal codes, the following three options can be considered.

First, Option 1 is free to use the complex quasi-orthogonal code without limitation on the length and use all complex quasi-orthogonal code sequences in the full length in the system that uses the Walsh orthogonal code and the variable data rate.

Second, option 2 can select one of the Walsh orthogonal code group and the complex quasi-orthogonal code group to create two orthogonal sets, and both groups can serve variable data rates.

Third, Option 3 can use the Walsh orthogonal code group and all complex quasi-orthogonal codes as one group to allow for support of variable data rates. In this case, random code characteristics may be generated between the complex quasi-orthogonal code groups.

In view of the characteristics of the three options described above, it is preferable to use a complex quasi-orthogonal code according to the type of application to be used. In other words, if only Walsh orthogonal codes are used, the modulating side and the demodulating side exchange the orthogonal orthogonal code numbers with each other. Number (Q` matrix of FIG. 4 I index of)). In this case, the orthogonal code group is referred to as group 0, and after that, the number of groups up to 2 ^m −1 is redefined.

A method of using the complex quasi-orthogonal code group in a system having a variable data rate like the orthogonal code group will be described. The element of the complex quasi-orthogonal code group consists of a Walsh orthogonal code corresponding to an orthogonal code number and a complex quasi-orthogonal code mask corresponding to a group number. The group number is any Is selected. In the complex quasi-orthogonal code group, a method of serving a variable data rate is used as a Walsh orthogonal code group with a pre-assigned orthogonal code number and assigned every length N. Just add. At this time, if the signal is represented by 0 and 1, the signal is added. When 1 and -1, the signal is multiplied.

6 illustrates an example of extending channel capacity using Walsh orthogonal code and complex quasi-orthogonal code in the forward link of IS-95 / IS-95A according to an embodiment of the present invention. FIG. 6 illustrates an example in which channels that can be allocated by Walsh orthogonal codes are used as they are in the IS-95 system and extended channel capacity using complex quasi-orthogonal codes. However, the Walsh orthogonal codes may be designated and used for common channels, and remaining Walsh orthogonal codes and complex quasi-orthogonal codes may be arbitrarily assigned to the traffic channels. In this case, the traffic channels mean dedicated channels. In addition, although the complex quasi-orthogonal code in FIG. 6 illustrates an example using a code having a length of 256, the length of the complex quasi-orthogonal code may be variably set as necessary.

In FIG. 6, the Walsh orthogonal code is denoted by w, and each channel is divided by a pre-assigned orthogonal code. In FIG. 6, the complex quasi-orthogonal code is denoted by s and is assigned to the traffic channel. As shown in FIG. 6, the forward link of IS-95 / IS-95A can perform 64 channel division using Walsh orthogonal codes, and the complex quasi-orthogonal codes correspond to four times the Walsh orthogonal codes. 256 channels can be distinguished. Therefore, as shown in FIG. 6, it can be seen that the use of Walsh orthogonal codes and complex quasi-orthogonal codes can increase the channel number four times.

7 is a diagram illustrating a transmitter configuration of a mobile communication system having a spreader using a Walsh orthogonal code and a complex quasi-orthogonal code according to an embodiment of the present invention. The configuration of the mobile communication system shown in FIG. 7 is different from that of the IS-95, and shows a configuration of a channel transmitter using a complex quasi-orthogonal code for the channel spreading code.

Referring to FIG. 7, the data bit stream X is input to the complex signal converter 710, converted into a complex signal, and outputs a real part Xi and an imaginary part Xq, respectively. The first signal converter 711 and the second signal converter 713 input a complex data bit stream Xi and Xq respectively output from the complex signal converter 710 to perform signal conversion. The first signal converter 711 converts 0 into a +1 signal and 1 into a -1 signal in the input bit stream, and demultiplexes the converted signal to output to the orthogonal code spreading and PN masking unit 719. The second signal converter 713 inputs an input traffic channel data bit stream to perform signal conversion. The second signal converter 713 converts 0 into a +1 signal and 1 into a -1 signal in the input bit stream, demultiplexes the converted signal and outputs the demultiplexed signal to the orthogonal code spreading and PN masking unit 719.

The quadratic complex quasi-orthogonal code generator 715 generates a quasi-orthogonal code QOFi and QOFq by inputting a complex quasi-orthogonal code index and a Walsh orthogonal code index. The complex quasi-orthogonal code generator 715 stores masks of the selected quasi-orthogonal code generated by the process as shown in FIG. 5 and a corresponding mask is selected by the complex quasi-orthogonal code index. In addition, the complex quasi-orthogonal code generator 715 includes a Walsh orthogonal code generator and generates a Walsh orthogonal code corresponding to the Walsh orthogonal code index. The complex quasi-orthogonal code generator 715 then generates the complex quasi-orthogonal code QOFi and QOFq by computing the selected quasi-orthogonal code mask and Walsh orthogonal code.

The PN code generator 717 generates the PN codes PNi and PNq of the real part and the imaginary part and applies them to the channel spreading and PN masking part 719. The channel spreader and PN masking unit 719 multiplies the outputs of the input signal converters 711 and 713 by a complex quasi-orthogonal code QOFi and QOFq in a set channel, respectively, and spreads the channel spread signal again through the PN codes PNi and PNq. Multiply by and PN mask to generate Yi and Yq signals. The baseband filter 721 filters and outputs Yi and Yq diffused and output from the channel spreader and PNS masking unit 719 into the baseband. The frequency shifter 723 transitions the signal output from the baseband filter 721 to an RF signal and converts the signal into a wireless transmission signal.

FIG. 7 illustrates a structure of a channel transmitter of a forward link and shows a structure of one channel transmitter using a complex quasi-orthogonal code.

Referring to FIG. 7, a user's terminal transmits 1 or 0 data bits through a call channel. The data of the channel are converted into a complex signal through the complex signal converter 710 and output to Xi and Xq, and are respectively applied to the corresponding first signal converter 711 and the second signal converter 713 so that 0 is a +1 signal. 1 is converted to a signal of -1, and then applied to the channel spreading and pien masking unit 719. Then, the channel spreading and PN masking unit 719 multiplies the input signal by the quasi-orthogonal code QOFi and QOFq generated by the complex quasi-orthogonal code generator 715, respectively, to generate baseband spread complex signals Yi and Yq, which are signals. Applied to baseband filter 717. In this case, the real component in the complex signal is Yi and the imaginary component is Yq. Then, the baseband filter 721 is modulated and filtered by an Offset Quadrature Phase Shift Keying (OQPSK) scheme, and the frequency shifter 723 converts the output of the baseband filter 721 into a spread radio signal of RF.

FIG. 8 is a diagram illustrating a configuration of channel spreading and PN masking unit 719 in which channel spreading is performed using the complex quasi-orthogonal codes QOFi and QOFq, and PN masking is a complex number using PNi and PNq.

Referring to FIG. 8, the spreader 811 receives the complex signals Xi and Xq of the channel and multiplies the complex quasi-orthogonal codes QOFi and QOFq, respectively, and outputs the channel spread di signal and dq signal. In this case, the signal di + dq output from the spreader 811 is a signal spread with a complex quasi-orthogonal code, and becomes (Xi + jXq) * (QOFi + jQOFq). The complex multiplier 813 complexly multiplies the spread signals di and dq output from the spreader 811 and the PN codes PNi and PNq output from the PEN code generator 815 to generate PN masked Yi and Yq. The signal Yi + JYq = (di + Jdq) ^* (PNi + jPNq) output from the complex multiplier 813 becomes. The complex multiplier 813 performs a complex arithmetic operation as shown in FIG. 8 to perform a PN masking function with a complex number.

10 and 11 illustrate a configuration example of the complex quasi-orthogonal code generator 715 of FIG. 7 according to an exemplary embodiment of the present invention. The complex quasi-orthogonal code generator 715 may be configured in other forms according to the structure of the mask. That is, the mask generated by the complex quasi-orthogonal code generator 715 may be generated as a value, separated into I and Q components, or may be configured in different forms depending on the case of the sign and the direction. In the embodiment of the present invention, FIG. 10 is a diagram showing the configuration of a complex quasi-orthogonal code generator when the quasi-orthogonal mask is output as a hexadecimal value as shown in Table 9, and FIG. As shown in Table 11, the structure of the complex quasi-orthogonal code generator when separated into I and Q values is output.

First, referring to FIG. 10, when an index of a quasi-orthogonal code is input to a quasi-orthogonal mask generator 1000, the quasi-orthogonal mask generator 1000 outputs a mask represented by a hexadecimal number according to the index of the quasi-orthogonal code. The quasi-orthogonal mask generator 1000 may directly generate a mask using an index of the quasi-orthogonal code. In addition, the quasi-orthogonal mask generator 1000 may store a mask of a quasi-orthogonal code expressed in hexadecimal, and may select and output a mask corresponding to the index of the quasi-orthogonal code. In addition, when the Walsh orthogonal code index is input to the Walsh orthogonal code generator 1010, the Walsh orthogonal code generator 1010 generates and outputs a Walsh orthogonal code corresponding to the Walsh orthogonal code index. At this time, the Walsh orthogonal code output from the Walsh orthogonal code generator 1010 is output as a value of 0 and 1. Then, the multiplier 1031 multiplies 2 to express the Walsh orthogonal code output from the Walsh orthogonal code generator 1010 as a hexadecimal number and outputs the multiplier 1033. Then, the adder 1033 adds and outputs the mask of the quasi-orthogonal code output from the quasi-orthogonal mask generator 1000 and the Walsh orthogonal code output from the multiplier 1031. At this time, the adder 1033 adds two signals inputted from the ternary point of view since all input signals are quaternary numbers. The signals added by the adder 1033 are again input to the signal converter 1020 to convert quasi-orthogonal codes into complex quasi-orthogonal codes, where 0 is converted to 1 + j, 1 is converted to -1 + j, and 2 is-. The real parts are output by the I signal QOFi, and the imaginary parts are output by the Q signal QOFq.

11, when the quasi-orthogonal code index is input to the I-component mask generator 1100 and the Q-component mask generator 1105, the I-component mask generator 1100 and the Q-component mask generator 1105 are respectively 0 and 1 corresponding to the quasi-orthogonal code index. The I component mask and the Q component mask represented by are generated and output. At this time, the I component mask and the Q component mask output from the mask generators 1100 and 1105 are applied to the adders 1133 and 1135, respectively. In addition, when an index of the Walsh orthogonal code is applied to the Walsh orthogonal code generator 1110, the Walsh orthogonal code generator 1110 generates and outputs a Walsh orthogonal code corresponding to the Walsh orthogonal code index. Is applied at 1135. Therefore, the adder 1133 adds the I component mask and the Walsh orthogonal code to generate an I component quasi-orthogonal code. The adder 1135 adds the Q component mask and the Walsh orthogonal code to output the Q component quasi-orthogonal code. The signal converters 1137 and 1139 convert 0 to +1, and 1 to -1 in the signals output from the corresponding adders 1133 and 1135, respectively, and apply them to the diffuser 811.

There are various expressions in expressing the mask of the above orthogonal professor sequence.

First, as shown in the above table, it can be expressed as a hexadecimal number of 0,1,2,3, and second, 1, -1, j by the gray map mentioned above. can be expressed by converting to -j, and the third is 1 + j, -1-j, -1 + j, 1-j in which 1, -1, j, -j is rotated by 45 degrees. The fourth can be expressed in the form of sign and phase by expressing the second expression 1, -1, j, -j in polar form, and the fifth is the polar form of the second expression 1, -1, j, -j. It can be expressed only in phase, and may be made of other complex expressions. Therefore, although the respective tables shown in the first embodiment are displayed in the above-mentioned hexadecimal form, they can be corresponded by the above-described conversion law, and thus, the same masks can be expressed.

As described above, in the method of expressing a complex number, there is a method of expressing a complex number into a real part and an imaginary part, and as another method, when the complex number is represented by coordinates in a gauss complex plane using polar form, It can be expressed as an absolute value representing the angle formed by the positive part of the real part and the distance from 0 to the coordinate. In this case, when the above quasi-orthogonal sequence is expressed as 1, -1, j, -j, the absolute value is always 1. And when the angle (Phase) exceeds 180 degrees, the effect of multiplying the complex number by -1 can be obtained. Therefore, in expressing the complex number, in addition to the method of expressing the real part and the imaginary part, in the Gauss complex plane, the coordinate and the sign of the positive part of the real part are represented by Equation 9 Can be expressed as:

If 1, -1, j, -j is expressed using Equation (9), it is as follows.

As can be seen from the example according to the above equation, the complex numbers 1, -1, j, -j may be represented by a sign and a phase. In the tables, masks represented by 0, 1, 2, and 3 are respectively It can be converted to 1, -1, j, -j by the gray map mentioned above, and for the quasi-orthogonal sequence represented by 1, -1, j, -j as in the example shown below, The sign is indicated by the sign control signal "0" and the phase control signal by "0", and the sign for -1 is the sign control signal "1" and the phase control signal is " 0 ", the sign for j is a sign control signal" 0 ", the phase control signal is" 1 ", and the sign for -j is a sign control signal. As "1", the phase control signal may be indicated as "1".

In the above embodiment, in a spreading device for spreading an input signal in a complex quasi-orthogonal sequence, when the input signal is spread by expressing the complex quasi-orthogonal sequence in polar form, the mask having a length of 256 in Table 38 is described. The sign and phase portions of the pole form of the mask having a length of 128 and <Table 23> are shown in Tables 45 and 46, respectively. At this time, the sign portion of the polar form "0" indicates that the sign is + and "1" represents-. In addition, the phase control value "Phase" represents a real component by keeping the phase of the signal as it is, and "1" represents an imaginary value by rotating the signal phase by 90 degrees.

FIG. 12 illustrates a diffuser 811 in which the input signals are spread using the masks as described above in the polar form of the quasi-orthogonal sequence.

12, input signals Xi and Xq are input to multipliers 1250 and 1252, respectively. At the same time, the Walsh orthogonal code generator 1232 generates a Walsh orthogonal code corresponding to the Walsh orthogonal code index for the assigned channel, and the sign generator 1234 is a sign of the quasi-orthogonal code corresponding to the quasi-orthogonal code index for the assigned channel. Generates a sign that indicates Then, the multiplier 1240 multiplies the generated Walsh orthogonal code and the signed value, and applies the multiplier 1250 to the multipliers 1250 and 1252. At this time, the multiplier 1250 inputs a signal multiplied by the input signal Xi, the sign of the Walsh orthogonal code and the quasi orthogonal code, and multiplies the two input signals to output Iin. The multiplier 1252 inputs a signal obtained by multiplying an input signal Xq by a sign of Walsh orthogonal code and a quasi orthogonal code, and multiplies the two input signals to output Qin. When Iin and Qin are output from multipliers 1250 and 1252, they are input to the rotor 1210. At this time, the phase code generator 1236 generates a phase value corresponding to the quasi-orthogonal code index, and the generated phase value is output as the rotation selection signal Qrot to the rotor 1210. Therefore, the rotor 1210 inputs the outputs of the multipliers 1250 and 1252 and controls the output phases of the multipliers 1250 and 1252 according to the rotation selection signal output from the phase code generator 1236. That is, when the phase value representing the angle of the quasi-orthogonal code is 0, the rotating unit 1210 outputs the input signal Iin + j Qin as di and dq signals, which are channel spread as it is, and if 1, j to the input signal Iin + j Qin. Multiply by to output -Qin + jIin as the channel spread di and dq signals.

Here, the quasi-orthogonal code indices applied to the sign generator 1234 and the phase code generator 1236 have the same value. In addition, the sign code generator 1234 and the phase code generator 1236 should have chip synchronization. Accordingly, the sign codes and the phase codes as shown in Tables 13 and 14 may be provided in the sign generator 1234 and the phase code generator 1236, and the sign code generator 1234 is a sign for a specific quasi-orthogonal code. (E.g., e1 sign), the phase code generator 1236 also generates a phase code (e.g., e1 phase) corresponding to the generated sign code, wherein the sign code and the phase code are chip synchronized. It becomes a state.

FIG. 13 shows a rotor 1210 according to FIG. 12.

Referring to FIG. 13, first, Iin is input to the D1 terminal of the selector 1320 and the D2 terminal of the selector 1325, and at the same time, Qin is input to the D1 terminal of the inverter 1310 and the selector 1325. When the input signal Qin is 1, the inverter 1310 converts the signal to -1 and -1 to +1 to apply the D2 terminal of the selector 1320. At the same time, a phase value Qrot indicating the angle of the quasi-orthogonal code is input to the selection terminals Enable of the selectors 1320 and 1325, respectively. Therefore, the selectors 1320 and 1325 select Iin and Qin signals received through the D1 terminal when the phase value is 0, respectively, and output them as channel spread di and dq signals, and -Qin received through the D2 terminal when the phase value is 1; And Iin signals are selected and output as channel spread di and dq signals, respectively.

As shown in Equation 9, the complex number can be expressed by the positive part of the real part, the phase and the sign in the Gaussian complex plane. Therefore, for the quasi-orthogonal sequence represented by 1, -1, j, -j, 1 denotes the sign code as 0, phase code as 0, -1 denotes the sign as 1, and phase code is 0. J denotes a sign code as 0 and a phase code as 1, -j denotes a sign code as 1 and a phase code as 1. Therefore, a mask of a quasi-orthogonal code, which can be represented as a complex number, is represented by a sign code and a phase code. First, by spreading a channel signal by mixing the sign code and the Walsh orthogonal code, a phase code corresponding to the sign code is used. By controlling the phase of the channel spread signal, the same result as that of the signal spread with the channel signal using a quasi-orthogonal code can be obtained.

In FIG. 12, an operation of spreading a quasi-orthogonal code by controlling the phase of the spread signal after spreading the channel signal using the sign code and the Walsh orthogonal code is described. After controlling the phase of the signal to be spread, the same spreading effect can be obtained even by spreading the phase-controlled channel signal using the sign code and the Walsh orthogonal code. That is, in FIG. 12, the rotor 1210 first controls the phases of the input signals Xi and Xq according to the phase code Qrot, and the multipliers 1250 and 1252 respectively output the phase-controlled Xi and Xq from the multiplier 1240 and the Walsh orthogonal code. Even if the signal is diffused and output as a mixed signal of, the same diffusion can be obtained with the quasi-orthogonal code.

In addition, unlike the method shown in FIG. 12, 1, -1, j, -j may be represented by only a phase code without a sign. Equation (12) below represents an expression capable of only a phase in this way.

If 1, -1, j, -j, is expressed using Equation 12, as follows.

As can be seen from the example according to Equation 12, the complex numbers 1, -1, j, -j may be represented by a phase, and as shown in the following example, quasi-orthogonality represented by 1, -1, j, -j 1 is a phase shift of 1 by 0 degrees, and the phase code for this is represented by "0", -1 is a phase shift of 1 by 180 degrees, and the phase code for this is represented by "2". j is a phase shift of 1 by 90 degrees, and the phase code for this is represented by "1", and -j is a phase shift of 1 by 270 degrees, and the phase code for this is represented by "3".

In the above embodiment, when the input signal is spread by expressing the complex quasi-orthogonal sequence in polar form in the spreading device which spreads the input signal in the complex quasi-orthogonal sequence, the mask having a length of 256 in Table 38 and < Table 38 and Table 23 may be used as it is for the portion of the mask having a length of 128 in Table 23. At this time, the phase control value "Phase" means that the phase of the signal to be spread is not rotated, and "1" means that the phase of the signal to be spread is rotated by 90 degrees. "2" means rotate the phase of the signal to be spread by 180 degrees, and "3" means rotate the phase of the signal to be spread by 270 degrees.

FIG. 14 illustrates a diffuser 811 that spreads input signals with the mask when the quasi-orthogonal sequence is expressed in polar form in FIG. 8.

14, input signals Xi and Xq are input to multipliers 1450 and 1452, respectively. At the same time, the Walsh orthogonal code generator 1423 generates a Walsh orthogonal code corresponding to the Walsh orthogonal code index for the assigned channel and applies it to the multipliers 1450 and 1452. Therefore, the multiplier 1450 multiplies the input signal Xi by the Walsh orthogonal code and outputs the channel spread Iin signal, and the multiplier 1452 multiplies the input signal Xq by the Walsh orthogonal code and outputs the channel spread Qin signal. The above Iin and Qin are outputted from multipliers 1450 and 1452 and input to the rotator 1410. The phase code generator 1436 simultaneously rotates the phase code Qrot representing the angle of the quasi-orthogonal code corresponding to the quasi-orthogonal code index of the assigned channel. Is entered. Then, the rotor 1410 controls the phase of the channel spread Iin and Qin signals according to the phase code Qrot. If the phase value is 0, the input signals Iin and j Qin are selected and output as the channel spread signals di and dq. If the phase value is 1, the input signals Iin and j Qin are respectively multiplied by j to select -Qin + jIin to be output as the channel spread signals di and dq.If the phase value is 2, the input signals Iin and j Qin are respectively- Select -Iin-jQin generated by multiplying by 1 to output the channel spread signals di and dq.If the phase value is 3, the channel spreads by selecting Qin-jIin generated by multiplying the input signals Iin and j Qin by -j, respectively. Output with signals di and dq.

FIG. 15 illustrates the structure of the rotor 1410 of FIG.

Referring to FIG. 15, Iin is first input to an inverter 1510, a D1 terminal of the selector 1520, and a D2 terminal of the selector 1525, and Qin is input to an inverter 1515, a D4 terminal of the selector 1520, and a D1 terminal of the selector 1525, respectively. The inverter 1510 inverts the input signal Iin and applies it to the D3 terminal of the selector 1520 and the D4 terminal of the selector 1525, and the inverter 1515 inverts the input signal Qin to the D2 terminal of the selector 1520 and the D3 terminal of the selector 1525, respectively. Is authorized. The phase code Qrot, which represents the angle of the quasi-orthogonal code, is input to the selectors 1520 and 1525, respectively. Then, the selectors 1520 and 1525 respectively control the phases of the spread signals Iin and Qin input according to the phase code. If the phase code is 0, the selectors 1520 and 1525 select and output the signals input to the D1 terminal, respectively. If the phase code is 1, the signals input to the D2 terminal are respectively selected and output. If the phase value is 2, the signals input to the D3 terminal are selected and output. If the phase value is 3, the signals are input to the D4 terminal. Each signal is selected and output.

In FIG. 14, an operation of first spreading a channel signal using Walsh orthogonal code and then spreading a quasi-orthogonal code by controlling the phase of the spread signal is described. After controlling the phase, the same spreading effect can be obtained even by spreading the phase-controlled channel signal using the Walsh orthogonal code. That is, in FIG. 14, the rotor 1410 first controls the phase of the input signals Xi and Xq according to the phase code Qrot, and the multipliers 1450 and 1452 respectively diffuse and output the phase-controlled Xi and Xq as mixed signals of Walsh orthogonal codes. In the same manner, the result can be obtained by the diffusion of the quasi-orthogonal code.

The despreading operation of the receiver receiving the output of the transmitter has the inverse structure of the spreading apparatus as shown in FIG. 7. The embodiment of the present invention looks at the despreading operation of the complex quasi-orthogonal code in the despreading apparatus.

FIG. 16 is a diagram illustrating a despreader structure of a reception structure for a complex quasi-orthogonal spreader in FIG. 12.

Referring to FIG. 16, channel spread signals (ie, PN despread signals) di and dq are input to multipliers 1650 and 1652, respectively. At this time, the Walsh orthogonal code generator 1632 generates a Walsh orthogonal code corresponding to the Walsh orthogonal code index, and the sign code generator 1634 generates a sign code corresponding to the quasi-orthogonal code index. The multiplier 1640 multiplies the generated Walsh orthogonal code and the sign code and applies them to the multipliers 1650 and 1652, respectively. Then, the multipliers 1650 and 1652 despread the input di and dq signals into a mixed signal of Walsh orthogonal and quasi orthogonal codes, respectively, and output Iin and Qin signals. When the Iin and Qin signals are output from the multipliers 1650 and 1652, they are input to the rotor 1610, and the phase code generator 1636 generates a phase code representing an angle of the quasi-orthogonal code corresponding to the quasi-orthogonal code index and applies it to the rotor 1610. do. Then, the rotating unit 1610 selects the input signals Iin and j Qin when the phase code is 0 and outputs them as the channel despread signals di and dq. When 1, the output Qin generated by multiplying the input signals Iin and j Qin by -j, respectively. Select jIin and output as channel despread signals di and dq.

In the channel despreader having the structure as shown in FIG. 16, the phase of the PN despread signals di and dq is first controlled by using a phase code, and the phase-controlled signal is despread with a multiplication signal signed with a Walsh orthogonal code. The same channel despreading result is obtained.

FIG. 17 shows the rotor 1610 according to FIG. 16.

17, when Iin is first input, Qin is input to the D2 terminal of the selector 1720 and the D1 terminal of the selector 1725, and at the same time, the Iin is input to the D1 terminal of the inverter 1710 and the selector 1720. When the input signal Iin is 1, the inverter 1710 converts it to -1, and if it is -1, converts it to +1 and outputs the converted signal. Accordingly, when the inverter 1710 inverts the input signal Iin and outputs the signal, the output signal is input to the D2 terminal of the selector 1725. At the same time, a phase code indicating the angle of the quasi-orthogonal code is input to the selectors 1720 and 1725, respectively. Accordingly, the selectors 1720 and 1725 select and output the signals of the D1 terminal when the phase code is 0, and select and output the signals of the D2 terminal when the phase code is 0.

FIG. 18 is a diagram illustrating a despreader structure of a receiver for a channel spreader having the structure shown in FIG. 14.

18, input signals di and dq are input to multipliers 1850 and 1852, respectively. At the same time, the Walsh orthogonal code generator 1423 generates a Walsh orthogonal code corresponding to the Walsh orthogonal code index for the assigned channel and applies it to the multipliers 1850 and 1852. Accordingly, the multiplier 1850 multiplies the input signal di by the Walsh orthogonal code and outputs the channel spread Iin signal, and the multiplier 1452 multiplies the input signal dq by the Walsh orthogonal code to output the channel spread Qin signal. The above Iin and Qin are output from multipliers 1850 and 1852 and input to the rotor 1810. The phase code generator 1836 simultaneously rotates the phase code Qrot representing the angle of the quasi-orthogonal code corresponding to the quasi-orthogonal code index of the assigned channel. Is entered. Then, the rotor 1810 controls the phases of the channel-spread Iin and Qin signals according to the phase code Qrot. If the phase value is 0, the input signals Iin and j Qin are selected and output as the channel despread signals Xi and Xq. If the phase value is 1, the input signals Iin and j Qin are respectively multiplied by j to select -Qin + jIin to be output as the channel despread signals Xi and Xq, and if the phase value is 2, the input signals Iin and j Qin are selected. Select -Iin-jQin generated by multiplying by -1 to output the channel despread signals Xi and Xq.If the phase value is 3, select Qin-jIin generated by multiplying the input signals Iin and j Qin by -j, respectively. And outputs the channel despread signals Xi and Xq.

FIG. 19 shows the structure of the rotor 1810 of FIG.

Referring to FIG. 19, Iin is first input to an inverter 1910, a D1 terminal of the selector 1920 and a D2 terminal of the selector 1925, and Qin is respectively input to the D1 terminal of the inverter 1915, the selector 1920, and the D1 terminal of the selector 1925, respectively. The inverter 1910 inverts the input signal Iin and applies it to the D3 terminal of the selector 1920 and the D4 terminal of the selector 1925, and the inverter 1915 inverts the input signal Qin to the D2 terminal of the selector 1920 and the D3 terminal of the selector 1925, respectively. Is authorized. In addition, the phase code Qrot representing the angle of the quasi-orthogonal code is input to the selectors 1920 and 1925, respectively. Then, the selectors 1920 and 1925 respectively control the phases of the spread signals Iin and Qin input according to the phase code. If the phase code is 0, the selectors 1920 and 1925 select and output the signals input to the D1 terminal, respectively. If the phase code is 1, the signals input to the D2 terminal are respectively selected and output. If the phase value is 2, the signals input to the D3 terminal are selected and output. If the phase value is 3, the signals are input to the D4 terminal. Each signal is selected and output.

In FIG. 18, an operation of spreading a quasi-orthogonal code by first despreading a channel signal using a Walsh orthogonal code and then controlling a phase of the despread signal is described. After controlling the phase of the signal, the same spreading effect can be obtained by despreading the phase controlled channel signal using the Walsh orthogonal code.

When the spreading operation is performed using the sign and phase as described above, the spreading apparatus may be implemented by another method.

When a mask of a complex quasi-orthogonal code is generated by a method according to an embodiment of the present invention and the mask of the quasi-orthogonal code is converted into a polar form to be generated as a sign code and a phase code, the phase code has a corresponding length. Represented by a specific Walsh orthogonal sign. That is, it can be seen that the values of the phase codes in the masks of the complex quasi-orthogonal codes shown in Tables 13 and 14 become specific Walsh orthogonal codes. Therefore, when the channel signal is spread and despread in the same manner as in FIGS. 12 and 16, the sequence of phases is actually the same as the sequence of Walsh orthogonal codes. That is, in the case of using a mask of a complex 256 orthogonal code of length 256, the sequence of phases for the mask e1 is the sequence of Walsh orthogonal code 213, and the sequence of phases for the mask e2 is 10. Is the sequence of Walsh orthogonal code, the sequence of phase for mask e3 is the sequence of Walsh orthogonal code 111, and the sequence of phase for mask e4 is the sequence of Walsh orthogonal code 242.

Therefore, when the channel is spread, a diffusion device having the configuration as shown in FIG. 20 can be used, which can be seen that the structure of FIG. 12 replaces a sequence of phases with a sequence of Walsh orthogonal codes. The Walsh orthogonal generator, which will be shown below, stores all Walsh orthogonal codes as a memory and retrieves and outputs the Walsh orthogonal code corresponding to the Walsh orthogonal code index. You can also generate and output it.

Referring to FIG. 20, when input signals Xi and Xq are input, the input signals Xi and Xq are input to multipliers 2050 and 2052, respectively. When the Walsh orthogonal code index k for channel allocation is input to the first Walsh orthogonal code generator 2060, the first Walsh orthogonal code generator 2060 outputs the k th Walsh orthogonal code corresponding to the Walsh orthogonal code index k. The Walsh orthogonal code, which is output together, is input to the multiplier 2040. At the same time, if the quasi-orthogonal code index t is input to the sine code generator 2070, the sine code generator 2070 outputs the t-sign, which corresponds to the quasi-orthogonal code index t, Is entered. At this time, the sign code generator 2070 may store a sign code shown in Table 13 and output a sign code corresponding to the mask index, and may also use a separate method for generating a sign code. You can also use the device. Then, the multiplier 2040 multiplies and outputs the input Walsh orthogonal code and the sign code, and the multiplied signals are applied to the multipliers 2050 and 2052, respectively. At this time, the multiplier 2050 multiplies the input I component input signal Xi and the multiplier 2040 and outputs the input signal to the rotor 2010, and the multiplier 2052 is output from the input Q component input signal Xq and multiplier 2040 and inputs the multiplier 2050. Multiply by and output to the rotor 2010.

As described above, when signals from multipliers 2050 and 2052 are input to the rotor 2010, a mask index t is input to the second Walsh quadrature generator 2065 and the second Walsh quadrature generator 2065 corresponds to the input mask index t. Print Walsh orthogonal code. In this case, when the sign code and the Walsh orthogonal code have a length of 256 and the sign code and the phase code of Table 13, if the Walsh orthogonal code index t is 1, the sequence of Walsh orthogonal code 213 is 2, a Walsh orthogonal code 10 is output, 3 is a Walsh orthogonal code 111, and a 242 Walsh orthogonal code is outputted. When the Walsh sequence output from the Walsh orthogonal code generator 2065 is input to the rotor 2010, the rotor 2010 performs an operation of rotating or not rotating the input signal according to the value of the sequence of the Walsh orthogonal code. Here, the rotor 2011 has the same configuration as that of FIG. 13.

The structure of FIG. 20 can reduce hardware complexity by using a Walsh orthogonal sequence instead of a phase code. That is, in the case of using the Walsh orthogonal code, the Walsh orthogonal code generator already provided in the channel spreader and the despreader can be used, so that the memory for storing the phase code or the device for generating the phase code is not used. This can reduce the hardware complexity.

In the above embodiment, in a spreading device for spreading an input signal in a complex quasi-orthogonal sequence, when the input signal is spread by representing a complex quasi-orthogonal sequence in polar form, a sign code value of length 256 is shown. Sign sign values having a length of and 128 may use values as shown in Tables 15 and 16, respectively. Here, the sign portion of the polar form "0" indicates that the sign is + and "1" indicates-.

Also, in FIG. 20, the rotor 2010 should operate at a very high clock such as a chip rate at which the clock speed of the input signal is the output speed of the Walsh orthogonal code. 21 shows that the rotation speed of the rotor 2110 is the same as the symbol rate since the input signal is symbols. Therefore, as shown in the structure of Fig. 21, a method of lowering the clock speed of the input signal stage of the rotor by changing the position of the rotor is shown.

Referring to FIG. 21, when the input signals Xi and Xq are input to the rotor 2110 at the same clock speed as the input signal, an index corresponding to the mask index t is input to the Walsh orthogonal code generator 2165 and the Walsh orthogonal code generator 2165 is applied. Generates a Walsh orthogonal code corresponding to the input mask index t. That is, in the case of using the sign code and the phase code of Table 13 having a length of 256, if the Walsh orthogonal index index t is 1, the sequence of Walsh orthogonal code No. 213 is output. If it is 3, the sequence of Walsh orthogonal code 111 is output, and if it is 4, the sequence of Walsh orthogonal code 242 is output. In this way, when a sequence of Walsh orthogonal codes output from the Walsh orthogonal code generator 2065 is input to the rotor 2110, the same operation as that of FIG. 16 is performed. At this time, if the rotor 2110 outputs Iin and Qin after the same operation as that of FIG. 16, the output Iin and Qin are input to the multipliers 2150 and 2152, respectively. At the same time, if the Walsh orthogonal code index k for channel assignment is input to the Walsh orthogonal code generator 2160, the Walsh orthogonal code generator 2160 outputs the kth Walsh orthogonal code corresponding to the Walsh orthogonal code index k. Is input to multiplier 2140. In addition, when the quasi-orthogonal code index t is input to the sign code generator 2170 at the same time as the above process, the sign code generator 2170 outputs a t-th sign code corresponding to the quasi-orthogonal code index t, and the output sign codes are multipliers. Is entered at 2140. In this case, the sign code generator 2170 may store a sign code shown in Table 13 as a memory and output a sign code corresponding to the mask index t, and also generate a sign code. You can also use a generator. The multiplier 2140 multiplies the Walsh orthogonal code and the sign and outputs the multiplied signals, and the multiplied signals are input to the multipliers 2150 and 2152, respectively. In this case, the multiplier 2150 multiplies and outputs the input Iin and the signal output from the multiplier 2140 and the multiplier 2152 multiplies and outputs the input Qin signal and the signal output from the multiplier 2140.

In the above process, the rotor of FIGS. 20 and 21 has a rotor internal structure as shown in FIG.

The quasi-orthogonal code mask function having excellent properties of condition 4 is a heat transfer function obtained in step 513 of the processes shown in FIG. 5 for generating a mask function of the quasi-orthogonal code. It could be obtained by using The thermal substitution function as described above is a thermal substitution function that makes an M sequence a Walsh orthogonal code, and such a thermal substitution function may exist in various ways. Therefore, other heat substitution functions other than the above-mentioned heat substitution functions may be used. At this time, by using an appropriate thermal substitution function among the various thermal substitution functions described above, quasi-orthogonal code mask functions satisfying the above <Condition 4> can be found. The embodiments described below provide a method of generating the mask sequence of the quasi-orthogonal code using the other thermal substitution function described above. The heat substitution function shown in the following examples is generated using a Trace Orthogonal Basis on Galois field GF (2m).

First, the trace orthogonal basis is a Galois field (Galois field) that satisfies the following condition. Subset of to be.

Thermal substitution function by the trace orthogonal base as above Can be generated as shown in Equation 11 below.

The mask function of another quasi-orthogonal code can be obtained by changing the heat substitution function in the quasi-orthogonal code generation method as described above. In particular, when using the heat substitution function generated from the trace orthogonal basis, other masks can be generated. Some pairs of the generated mask functions of the quasi-orthogonal code may be selected to completely satisfy the quasi-orthogonal code condition 1-condition 4. In the following embodiment, a method of obtaining a pair of orthogonal codes that satisfies quasi-orthogonal code condition 1-condition 4 using a trace orthogonal basis in a method of using various heat substitution functions is shown as a specific example.

Example

An embodiment of the present invention for generating a sequence of quasi-orthogonal codes that satisfies the quasi-orthogonal code condition 1-condition 4 is 511, 515, 517 in the process of generating a quasi-orthogonal code mask proceeding as shown in FIG. Step 519 is the same, and the operation of step 513, which is a process of generating a heat substitution function, uses a trace orthogonal basis method. Therefore, an embodiment of the present invention will be described with reference to the step of generating the heat substitution function.

Herein, an operation of generating a thermal substitution function using a trace orthogonal basis method in generating masks of quasi-orthogonal codes satisfying condition 1 to condition 4 according to an embodiment of the present invention will be described. In an embodiment of the present invention, it is assumed that a mask of a quasi-orthogonal code having a length of 2 ⁷ = 128 is generated. Here, the generated polynomial of galoache to obtain the mask of the quasi-orthogonal code In this case, the trace orthogonal basis used Suppose you use, but ( Generated polynomial In the following, the set of basis is referred to as orthogonal basis set. At this time, when the order of the trace orthogonal bases is changed, the partial correlation of the generated mask of the quasi-orthogonal code is changed. Thus, the order of the trace orthogonal bases is in the order specified above.

First, the column substitution function for the code length 128 may be obtained by using Equation 11, where Equation 11 is a binary expansion expression of numbers from 1 to 127 first. After expressing Each of the corresponding trace orthogonal basis The elements on the Galoa finite body calculated by substituting these can be obtained by taking the logarithm on the finite body. To illustrate this process, we first use numbers from 1 to 127 in binary decimal format. Expressed as

:

:

At this time, in the above expression Trace orthogonal basis corresponding to the respective order The process of substituting silver in, silver in, silver in, silver in, silver in, silver in, silver Substituting), an elemental column on a galoa finite body is generated.

:

:

The elemental columns of Galoache obtained through the above calculation are the basic elements of Galoache. By taking the logarithm of the base (i.e., listing the exponential powers of the respective element sequences), we can get the thermal substitution function for the code length 128 above.

Therefore, according to Equation 11 Is obtained as follows.

Heat substitution function as above Is applied to step 513 of the quasi-orthogonal code generation process to generate a mask to obtain a quasi-orthogonal code mask that satisfies the following condition 4.

22 is a flowchart illustrating a process of generating the heat substitution function as described above.

Referring to FIG. 22, when the base bis are input in step 513a, the heat substitution function shown in Equation 11 is performed in step 513b. Create Then calculated in step 513b Using step 515, the generation process 515 is performed, and the subsequent process is the same as the generation process.

The heat substitution function as described above may be generated from the bases satisfying the condition of Equation 10. The case of length 256 and 512 may also be performed through the same process. It is possible to create masks of satisfactory quasi-orthogonal codes.

Tables 18 and 19 shown below are quasi-orthogonal code masks of length 256 and 512, respectively, and are masks of quasi-orthogonal code that fully satisfy condition 4 generated from the base shown below.

As described above, the complex numbers 1, -1, j, -j may be represented by a sign and a phase, which are represented by the marks of Tables 18 and 19 and complex quasi-orthogonal codes. Masks represented by 0, 1, 2, 3 in the other tables can be converted into 1, -1 j, -j by the gray map mentioned above, respectively. In addition, for the sequence of quasi-orthogonal codes represented by 1, -1, j, -j as in the example shown below, the sign for 1 may be represented by "0", and the phase code may be represented by "0". The sign for -1 can be represented by "1" and the phase sign can be represented by "0", the sign for j can be represented by "0" and the phase sign by "1",- The sign for j may be represented by "1" and the phase code by "1".

In the above embodiment, in the spreading apparatus for spreading an input signal by a sequence of complex quasi-orthogonal codes, when the input signal is spread by expressing the sequence of complex quasi-orthogonal codes in polar coordinates, For the mask of length 128, the mask of length 256 in <Table 18> and the mask of length 512 in <Table 19>, the Sign and Phase portions of the polar form are shown in Tables 20a and 21a, respectively. > And <Table 22a>. At this time, the sign portion of the polar form "0" indicates that the sign is + and "1" represents-. A phase of "0" indicates a real component by leaving the signal phase intact, and a value of "1" represents an imaginary value by rotating the signal phase by 90 degrees.

Table 20a below shows values obtained by converting 128 orthogonal code masks of length 128 that satisfy condition 1 to condition 4 into sign and phase in polar form.

Table 21a below shows values obtained by converting semi-orthogonal code masks of length 128 that satisfy condition 1 to condition 4 into sign and phase in polar form, as shown in Table 18.

Table 22a shows values obtained by converting semi-orthogonal code masks having a length of 128 satisfying Condition 1 to Condition 4 to a sign and phase in polar form as shown in Table 19.

At this time, the phase values shown in Tables 20a, 21a, and 22a are specific Walsh orthogonal code values of the corresponding lengths. That is, in the mask of the orthogonal code length 128 shown in Table 20a, the phase value for e1 is the same as Walsh orthogonal code 127, and the phase value for e2 is the same as Walsh orthogonal code 89. , the phase value for e3 is the same as Walsh Orthogonal Code 38. (Assuming that Walsh orthogonal code with a length of 128 is 0-127). In addition, in the case of a mask of a quasi-orthogonal code having a length of 256 shown in Table 21a, the phase value for e1 is the same as the Walsh orthogonal code 130, and the phase value for e2 is the same as the Walsh orthogonal code 173, The phase value for e3 is the same as the Walsh orthogonal code 47 (assuming that the number 256 Walsh orthogonal code is 0-255). In addition, in the mask of the quasi-orthogonal code having a length of 512 shown in Table 22a, the phase value for e1 is the same as Walsh orthogonal code 511, and the phase value for e2 is the same as Walsh orthogonal code 222. The phase value for e3 is the same as Walsh's orthogonal code 289 (we assume that Walsh's number of length 512 is 0-511).

As described above, when the quasi-orthogonal code is used for channel spreading and despreading, only the wrapped values are stored in the channel spreading and despreading table as shown in <Table 20b>, <Table 21b>, and <Table 22b>, and the phase value is Walsh. It can be seen that it has the same effect even when generated using an orthogonal code generator.

Therefore, as described above, in the embodiment of the present invention, three types of quasi-orthogonal codes that can be used in the channel spreader and the despreader can be generated. That is, in the exemplary embodiment of the present invention, masks having quasi-orthogonal codes that completely satisfy the condition 1 to condition 4 may be generated using the trace orthogonal basis as shown in FIGS. 5 and 22.

In this case, masks of quasi-orthogonal codes generated according to the procedures of FIGS. 5 and 22 are represented in a complex form, which are generated as shown in Tables 17 and 19.

First, when channel spreading and despreading are performed using masks of quasi-orthogonal codes as shown in Tables 17 to 19, the spreading code generator may be designed to have a structure as shown in FIG. 10 or 11. In the channel spreading and despreading apparatus using the mask having the structure of FIG. 10 or FIG. 11, the channel spreading code is Walsh orthogonal to the mask of the assigned quasi-orthogonal code as shown in Tables 17 to 19. The code is added to generate a quasi-orthogonal code for channel spreading. The quasi-orthogonal code mask generator of the diffusion code generator is designed to store masks as shown in Tables 17 to 19, and to select and output a mask of the quasi-orthogonal code according to the assigned mask index. can do. In addition, the quasi-orthogonal code mask generator may design and implement a device capable of generating masks as shown in Tables 17 and 19.

Secondly, masks of complex quasi-orthogonal codes as shown in Tables 17 and 19 can be converted to polar form and expressed as a sign code and a phase code as shown in Table 20a to Table 22a. When channel spreading and despreading are performed using a mask having a quasi-orthogonal code as shown in Tables 20a to 22a, the channel spreader can be designed as shown in FIGS. 16 and 18 may be designed. The channel spreading and despreading device first multiplies a specified Walsh orthogonal code and a sign code, and spreads the signals of the input I and Q channels into the multiplication signal, respectively. Thereafter, the spread signals are rotated using the phase code to generate a channel spread signal. In addition to the channel spreading method described above, the phase spreading signal is first controlled by using a phase code, and then the same spreading effect is obtained by spreading a phase-controlled input signal using a mixed signal of a sign code and a Walsh orthogonal code. You can get it. The channel despreading operation is performed in the same procedure.

In the channel spreading and despreading apparatus, the sign code generator and the phase code generator store masks as shown in Tables 20a to 22a as tables, and select masks of quasi-orthogonal codes according to the assigned mask indices. It can be designed to output structure. In this case, the mask index t for selecting the sign code and the phase code should use the same mask index. In addition, the sign code generator and the phase code generator may be implemented by designing a device capable of generating sign codes and phase codes as shown in Tables 20a to 22a.

Third, in the masks shown in Tables 20a to 22a, the phase code has the form of a specific Walsh orthogonal code. Therefore, it can be seen that the phase codes in the masks shown in Tables 20a to 22a are specific Walsh orthogonal codes of corresponding lengths. Therefore, when channel spreading and despreading are performed, the channel spreading and despreading apparatus as shown in FIGS. 21 and 22 has a sign code as shown in Tables 20b and 22b, and the phase code is a conventional Walsh orthogonal code. It can be designed with the structure used. The channel spreading and despreading device first multiplies a specified Walsh orthogonal code and a sign code, and spreads the signals of the input I and Q channels into the multiplication signal, respectively. Subsequently, the channel spread signal is generated by controlling the phase of the spread signals using the designated second Walsh code. In addition, a method different from the channel spreading method described above may be used. The first spreading signal can be obtained by controlling the phase of the input signal using the second Walsh orthogonal code, and then spreading the phase controlled input signal using the mixed signal of the sign and Walsh orthogonal codes. The channel despreading operation is performed in the same procedure.

In the channel spreading and despreading apparatus, a sign code generator stores masks as shown in Tables 20b to 22b as a table, and a second Walsh code generator generates specific Walsh orthogonal codes for controlling a phase. It can be configured as a device or a table. Therefore, the sign code generator and the second Walsh orthogonal code generator may be designed to generate a sign code and a second Walsh orthogonal code corresponding to a mask index allocated for channel spreading. In this case, the mask index t for selecting the sign code and the second Walsh orthogonal code should use the same mask index. In addition, the sign code generator and the second Walsh orthogonal code generator may be implemented by designing a device capable of generating sign codes and phase codes as shown in Tables 20b and 22b.

As described above, in the exemplary embodiment of the present invention, a complex quasi-orthogonal code having minimal interference with orthogonal codes can be generated, and regardless of the limitation of the orthogonal codes in a mobile communication system that distinguishes channels using orthogonal codes. There is an advantage that the channel capacity can be increased by using a complex quasi-orthogonal code.

Claims (21)

A method for generating a complex quasi-orthogonal code for channel spread in a code division multiple access communication system, Generating a specific sequence having a specific length N and a specific sequence having excellent overall correlation with the emsequence; Generating a predetermined number of specific sequences by cyclically shifting the specific sequence; Mask shifts are generated by thermally replacing the cyclically shifted specific sequences in the same manner as the thermal substitution method of cyclically shifting the emsequence to generate a predetermined number of emsequences and converting the generated sequences into Walsh orthogonal codes. Process, Generating quasi-orthogonal code candidate groups by computing Walsh orthogonal codes having the same length as the mask candidates and the mask candidates; Among the generated quasi-orthogonal code candidate groups, candidates for quasi-orthogonal code satisfying partial correlation with Walsh orthogonal codes and partial correlation with other quasi-orthogonal codes are selected, and a mask related to generation of the selected quasi-orthogonal codes. A method for generating a complex quasi-orthogonal code in a code division multiple access communication system. The method of claim 1, wherein the generating of the mask candidates comprises: Selecting one of a plurality of trace orthogonal basis sets given by a generation polynomial for generating the emsequence, Binary representation of each of 1,2, ..., N-1 for a specific length N C _m-1 2 ^m-1 + C _m-2 2 ^m-2 + ... + C ₀ 2 ⁰ (C _m-1 , C _m-2 , ..., C ₀ is 0 or 1), An element sequence of a Galloa field substituted by the selected orthogonal set instead of 2 ^m-1 , 2 ^m-2 , ..., 2 ⁰ and having the length N-1 and represented by the power of root α of the generated polynomial Process of generating, Generating a heat substitution function by taking a log of each element of the generated element string below the α; And generating the mask candidates by thermally replacing the specific sequences with the generated heat substitution function. The method of claim 2, wherein the specific sequence is a read-only sequence. 4. The method of claim 3, wherein the step of cyclically shifting the specific sequence further comprises inserting zeros in front of the shifted specific sequences. The method of claim 3, wherein the selecting of the mask comprises: The correlation value of each part of each length N / M obtained by dividing the total length N of the complex quasi-orthogonal code candidate and the Walsh orthogonal code by M is A first process of selecting a mask generating the quasi-orthogonal code candidate as a mask of the complex quasi-orthogonal code when not exceeding; The correlation value of each part of each length N / M obtained by dividing the total length N of the complex quasi-orthogonal code candidate and the other complex quasi-orthogonal code generated by the mask selected in the first step by M The method for generating a complex quasi-orthogonal code of a code division multiple access communication system comprising: selecting and storing a mask for generating the quasi-orthogonal code candidate as a mask of the complex quasi-orthogonal code when not exceeding. . . 4. The method of claim 3, wherein the mask candidate generated when N is 128 is as shown in Table 23 below. 4. The method of claim 3, wherein the mask candidate generated when N is 256 is as shown in Table 24 below. 4. The method of claim 3, wherein the mask candidates generated when N is 512 are as shown in Table 25 below. The complex quasi-orthogonality of the code division multiple access communication system according to claim 8, wherein the mask shown in Table 23, generated when N is 128, is converted into a polar form and converted into a sign and phase. Sign generation method. 10. The complex quasi-orthogonality of the code division multiple access communication system according to claim 9, wherein the mask shown in Table 24, generated when N is 256, is converted into a polar form and converted into a sign and phase. Sign generation method. 11. The method of claim 10, wherein the mask generated as shown in Table 25 when N is 512 is converted into a polar form, and converted into a sign code and a phase code, and the complex of the code division multiple access communication system as shown in Table 28 below. How to generate quasi-orthogonal codes. In the channel spreading device of a code division multiple access communication system, A Walsh orthogonal code generator that generates a Walsh orthogonal code corresponding to the Walsh orthogonal index of the assigned channel; A sign code generator for storing sign codes as shown in Table 29 and generating a sign code corresponding to a mask index ei (i = 1, 2, 3) of an allocated channel; A phase code generator for storing phase codes as shown in Table 29 and generating a phase code corresponding to the mask index ei (i = 1, 2, 3) of the allocated channel; Spreaders for spreading the input signal by a spreading code in which the generated Walsh orthogonal code and the sign code are mixed; And a rotator configured to phase-control signals output from the spreaders by the phase code to generate a channel spread signal. In the channel spreading device of a code division multiple access communication system, A Walsh orthogonal code generator that generates a Walsh orthogonal code corresponding to the Walsh orthogonal index of the assigned channel; A sign code generator for storing sign codes as shown in Table 30 and generating a sign code corresponding to a mask index ei (i = 1, 2, 3) of an allocated channel; A phase code generator for storing phase codes as shown in Table 30 and generating a phase code corresponding to the mask index ei (i = 1, 2, 3) of the allocated channel; Spreaders for spreading the input signal by a spreading code in which the generated Walsh orthogonal code and the sign code are mixed; And a rotator configured to phase-control signals output from the spreaders by the phase code to generate a channel spread signal. In the channel spreading device of a code division multiple access communication system, A Walsh orthogonal code generator that generates a Walsh orthogonal code corresponding to the Walsh orthogonal index of the assigned channel; A sign code generator for storing sign codes as shown in Table 31 and generating a sign code corresponding to a mask index ei (i = 1, 2, 3) of an allocated channel; A phase code generator for storing phase codes as shown in Table 31 and generating a phase code corresponding to the mask index ei (i = 1, 2, 3) of the allocated channel; Spreaders for spreading the input signal by a spreading code in which the generated Walsh orthogonal code and the sign code are mixed; And a rotator configured to phase-control signals output from the spreaders by the phase code to generate a channel spread signal. In the channel spreading device of a code division multiple access communication system, A first Walsh orthogonal code generator for generating a Walsh orthogonal code corresponding to the Walsh orthogonal index of the assigned channel; A sign code generator for generating a sign code corresponding to the mask index of the allocated channel; Generating a second Walsh orthogonal code corresponding to the mask index of the allocated channel, wherein the second Walsh orthogonal code is a signal for controlling a phase of the channel spread signal; A spreader for spreading the input signals by spreading codes each having a first Walsh orthogonal code and a sign code mixed therein; And a rotator configured to generate a channel spread signal by controlling the phases of the spread signals by the second Walsh orthogonal code, respectively. 18. The method of claim 17, wherein when the length of the spreading code has a length of 128, the sign code generator comprises a sign code table as shown in Table 32, the second Walsh code generator is to the e1 sign code; The phase value for the 127 is Walsh orthogonal code, the phase value for the e2 sign is 89 Walsh orthogonal code, and the phase value for the e3 sign is 38 Walsh orthogonal code. Channel spreader of communication system. 18. The method of claim 17, wherein when the length of the spreading code has a length of 256, the sign code generator is provided with a sign code table as shown in Table 33, the second Walsh code generator is to the e1 sign code; Phase value for e2 sign code, phase number for e2 sign code is 173 Walsh orthogonal code, and phase value for e3 sign code is 47. Walsh orthogonal code. Channel spreader of communication system. 18. The method of claim 17, wherein when the length of the spreading code has a length of 512, the sign code generator comprises a sign table as shown in Table 34, the second Walsh cross-signal generator to the e1 sign code The phase value for e2 sign code is the phase value for e2 sign code, the phase value for e2 sign code is 222 Walsh orthogonal code, and the phase value for e3 sign code is 289 Walsh orthogonal code. Channel spreader of communication system. In the channel spreading device of a code division multiple access communication system, A first Walsh orthogonal code generator for generating a Walsh orthogonal code corresponding to the Walsh orthogonal index of the assigned channel; A sign code generator for generating a sign code corresponding to the mask index of the allocated channel; Generating a second Walsh orthogonal code corresponding to the mask index of the allocated channel, wherein the second Walsh orthogonal code is a signal for controlling a phase of the channel spread signal; A rotor for controlling phases of the input signals by the second Walsh orthogonal code, respectively; And a spreader configured to spread the phase-controlled input signals by a spreading code mixed with a first Walsh orthogonal code and a sign code to generate a channel spread signal.