JP3303137B2 - Cyclic extension code combination generation device, transmission device, reception device, communication system, transmission method, reception method, and information recording medium - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a cyclic extension code combination generating apparatus, a transmitting apparatus, a receiving apparatus, a communication system, a transmitting method, a receiving method, and an information recording medium.

In particular, a cyclic extension code combination generating apparatus, a transmitting apparatus, and the like suitable for realizing code division multiplex communication having a high transmission capacity, being less affected by delay waves, and having a small number of parallel transmissions,
The present invention relates to a receiving device, a communication system, a transmitting method, a receiving method, and an information recording medium on which a program for realizing these is recorded.

[0003]

2. Description of the Related Art Conventionally, techniques of code division multiplex communication using an M-sequence, a Gold code, a bulk code, an orthogonal code obtained from a Walsh function, and the like have been proposed. These technologies take advantage of the low cross-correlation of the codes used,
It is possible to multiplex a plurality of signals or to obtain only a desired signal from the multiplexed signals. The multiplex communication using these spread code sequences is described in the following documents, for example.

[0004] Habuchi, Hasegawa, Hakura, Haneishi "Code division multiplexing using Manchester coded orthogonal sequences" (Transactions of the Institute of Electronics, Information and Communication Engineers, B-II, J74-B-II, No. 5, May 1991)

On the other hand, there has been proposed a method of using a modified M-sequence obtained by modifying the M-sequence and adding a DC component bias thereto. This is described in the following literature, for example.

Sumiyoshi, Tanimoto, Komai "Theoretical Study on Synchronous Spread Spectrum Multiplexing" (IEICE Technical Report CS81-11 April 1981)

Further, the inventors are studying a communication system and the like using a cyclic extension code in which these codes are cyclically extended so as to be less affected by a delayed wave.

[0008]

However, there is a great demand for a technology for realizing a larger capacity transmission.

On the other hand, if the number of parallel transmissions is increased, the dispersion of the transmission signal power is increased. Therefore, it is necessary to use an amplifier having excellent non-linearity. However, this leads to a problem of an increase in cost. . Therefore, it is necessary to satisfy the condition that the number of parallel transmissions should be reduced as much as possible.

Further, there is a strong demand to maintain the property of being hardly affected by delayed waves.

The present invention has been made to solve the above-mentioned problems, and is suitable for realizing code division multiplex communication having a high transmission capacity, less affected by delay waves, and a small number of parallel transmissions. It is an object of the present invention to provide an apparatus for generating a cyclic extension code combination, a transmitting apparatus, a receiving apparatus, a communication system, a transmitting method, a receiving method, and an information recording medium on which a program for realizing these is recorded.

[0012]

In order to achieve the above object, the following invention is disclosed in accordance with the principle of the present invention.

A cyclic extension code combination generating apparatus according to a first aspect of the present invention is configured to include a cyclic section, an extension section, and a combination section.

Here, the cyclic unit generates N codes obtained by circulating a basic code having a length of n bits by 0, 1,..., N−1 bits.

On the other hand, for each of the generated N codes, the extension unit adds the first L bits and the last J bits of the code to the end and the top of the code, respectively.
Generate cyclic extension codes.

Further, the combination unit generates 2 ^H combinations for selecting K cyclic extension codes from N cyclic extension codes so as to satisfy the following condition. -Each of the generated 2 ^H combinations includes a cyclic extension code having the same cyclic bit number. -For each of the 2 ^H combinations generated, the difference between the number of cyclic bits of the K cyclic extension codes included in the combination is greater than the maximum allowable bit number Q of delay.

In the cyclic extension code combination generating apparatus according to the present invention, the basic code is a spread code (for example, an M sequence, a Gold code sequence,
Orthogonal code sequence obtained from Walsh function, or
(Code included in the Manchester-coded orthogonal sequence).

[0018] A transmitting apparatus according to a second aspect of the present invention is configured to include a dividing unit, a selecting unit, a code division multiplexing unit, and a transmitting unit.

Here, the division unit divides the W-bit information to be transmitted into H-bit information and WH-bit information.

On the other hand, the selecting section is configured to generate a cyclic extension code associated with the divided H-bit information on a one-to-one basis from the combination of 2 ^H cyclic extension codes generated by the cyclic extension code combination generating apparatus. Select the combination of

Further, the code division multiplexing section outputs the divided W
-Code division multiplexing of H-bit information is performed by using K cyclic extension codes included in the selected combination of cyclic extension codes as spreading codes.

Then, the transmitting unit transmits the code-division multiplexed information.

Further, in the transmitting apparatus of the present invention, the code division multiplexing unit uses a cyclic extension code having the same number of cyclic bits included in any combination of 2 ^H cyclic extension codes as a spreading code for a pilot signal. Can be configured.

[0024] A receiving apparatus according to a third aspect of the present invention is configured to include a receiving section, an estimating section, an acquiring section, a restoring section, and an output section.

Here, the receiving unit receives the information transmitted from the transmitting device.

On the other hand, from the N codes obtained by circulating the basic code having a length of N bits by 0, 1,... Is selected, and it is estimated that K cyclic extension codes corresponding to the combination are used as spreading codes for code division multiplexing.

Further, the acquiring unit acquires H-bit information associated with the estimated combination of K codes on a one-to-one basis.

Then, the decompression unit uses the estimated combination of K codes as a despreading code to extract W-
The H-bit information is restored.

On the other hand, the output unit outputs W by combining the acquired H-bit information and the restored W-H bit information.
It outputs bit information as transmitted information.

[0030] A communication system according to a fourth aspect of the present invention is configured to include the transmission device and the reception device that receives information transmitted from the transmission device.

A cyclic extension code combination generating method according to a fifth aspect of the present invention is configured to include a cyclic step, an extension step, and a combination step.

Here, in the cyclic step, N codes are generated by rotating the basic code having a length of N bits by 0, 1,..., N−1 bits.

On the other hand, in the extension step, for each of the generated N codes, the first L bits and the last J
The N bits are added to the end and the beginning of the code, respectively, to generate N cyclic extension codes.

Further, in the combination step, 2 ^H combinations for selecting K cyclic extension codes from N cyclic extension codes are generated so as to satisfy the following condition.・ 2 ^H generated
Each of the combinations includes a cyclic extension code having the same number of cyclic bits. -For each of the 2 ^H combinations generated, the difference between the number of cyclic bits of the K cyclic extension codes included in the combination is greater than the maximum allowable bit number Q of delay.

In the cyclic extension code combination generating method according to the present invention, the basic code is a spreading code used in code division multiplex transmission (for example, an M sequence, a Gold code sequence, an orthogonal code sequence obtained from a Walsh function, or , Manchester-coded orthogonal sequence).

The transmitting method according to the sixth aspect of the present invention is configured to include a dividing step, a selecting step, a code division multiplexing step, and a transmitting step.

Here, in the dividing step, W-bit information to be transmitted is divided into H-bit information and WH-bit information.

On the other hand, in the selection step, the cyclic extension code associated with the divided H-bit information on a one-to-one basis is selected from the combination of 2 ^H cyclic extension codes generated by the above-mentioned cyclic extension code combination generating method. Select the combination of

Further, in the code division multiplexing step, the divided WH bit information is code division multiplexed using K cyclic extension codes included in the selected combination of cyclic extension codes as spreading codes.

Then, in the transmitting step, the code-division multiplexed information is transmitted.

In the transmission method of the present invention, in the code division multiplexing step, cyclic extension codes having the same number of cyclic bits included in any of the combinations of 2 ^H cyclic extension codes are used as spreading codes for pilot signals. Can be configured.

A receiving method according to a seventh aspect of the present invention is configured to include a receiving step, an estimating step, an acquiring step, a restoring step, and an output step.

Here, in the receiving step, information transmitted by the transmission method is received.

On the other hand, in the estimation step, the basic code having a length of N bits is circulated by 0, 1,..., N−1 bits.
A combination of K codes having a high correlation with the received information is selected from the N codes, and it is estimated that K cyclic extension codes corresponding to the combination are used as spreading codes of code division multiplexing.

Further, in the obtaining step, H-bit information associated with the estimated K code combinations on a one-to-one basis is obtained.

In the restoration step, WH bit information is restored from the received information using the estimated combination of K codes as a despreading code.

On the other hand, in the output step, W-bit information obtained by combining the obtained H-bit information and the restored W-H bit information is output as transmitted information.

Computer (digital signal processing hardware, DSP (Digital Signal Processor), FPG
A (Field PrograJJable Gate Array). ),
The above-mentioned cyclic extension code combination generating apparatus, transmitting apparatus, and a program to function as a receiving apparatus and a combination of the cyclic extension codes used in the communication system of the present invention can be stored in a compact disk, floppy disk, hard disk, magneto-optical disk, digital video disk. , A magnetic tape, a semiconductor memory, or another computer-readable information recording medium.

Information processing device having storage function, calculation function, input function, transmission function, reception function, etc. (general-purpose computer, game machine, portable information terminal, mobile phone, etc.)
In executing the program recorded on the information recording medium of the present invention or using the combination of the cyclic extension codes recorded on the information recording medium of the present invention, the above-mentioned cyclic extension code combination generating apparatus, transmitting apparatus, A receiving apparatus, a communication system, a cyclic extension code combination generating method, a transmitting method, and a receiving method can be realized.

Further, independently of the information processing apparatus, an information recording medium in which the program of the present invention and the combination of the cyclic extension codes are recorded can be distributed and sold.

[0051]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below. The embodiments described below are for explanation, and do not limit the scope of the present invention. Therefore, those skilled in the art can adopt embodiments in which each of these elements or all elements are replaced with equivalents, and these embodiments are also included in the scope of the present invention.

In the following description, a code included in the M-sequence will be described as a basic code for easy understanding. And these embodiments are also included in the scope of the present invention.

(First Embodiment) FIG. 1 shows a first embodiment of the present invention.
FIG. 10 is an explanatory diagram showing a state of a cyclic extension code used in the embodiment. Hereinafter, description will be made with reference to this figure.

In the present embodiment, as shown in FIG. 3A, an M sequence of five stages is used as the basic code 102. The code length of the M sequence is 31 (b1, b2, ..., b31).

On the other hand, a combination of 31 cyclic extension codes 101 is generated with the following specifications.・ Allowable number of chips for synchronization deviation is 2. The number of chips Q corresponding to the maximum permissible delay time of the delay wave is 2. -The number of chips to match the transmission clock is two.

Therefore, the number of leading chips L (the number of chips allowed for synchronization deviation) is 2, and the number of ending chips J (the sum of the number of chips Q corresponding to the maximum allowable delay time of the delay wave and the number of chips to match the transmission clock). ) Is 4, and the code length of the cyclic extension code is 31 + 2 + 4 = 37.

First, 31 cyclic codes 103 are generated from the five-stage M-sequence shown in FIG. These are obtained by cyclically shifting (rotating) the 5-stage M-sequence shown in FIG. 9A by 0, 1,..., 30 bits. In the following, these 31 cyclic codes 103 are appropriately represented as c1, c2,..., C31, respectively. In FIG. 3B, c1, c2, and c31 are shown as the cyclic codes 103.

Next, these 31 cyclic codes 103
, 4 bits of the number of trailing chips are obtained from the beginning of the cyclic code 103, 2 bits of the number of leading chips are acquired from the end of the cyclic code 103, and these are added to the beginning and end of the cyclic code 103, respectively. to add.

The 31 codes thus obtained are:
This is a cyclic extension code 101 used as a spreading code in the present embodiment. In the following, these 31 cyclic extension codes 101 are appropriately represented as e1, e2, ..., e31, respectively. FIG. 3C shows e1, e2, and e31 as the cyclic extension codes 101.

(Generation of Combination of Cyclic Extension Codes) In this embodiment, transmission is performed by code division multiplexing of five channels. Of these, one channel is used for pilot signals. Therefore, four channels can be used to transmit information.

It is assumed that QPSK is used as primary modulation before code division multiplexing. Therefore, two bits can be transferred for each channel per predetermined unit time. Therefore, the information that can be transmitted by code division multiplex depending on the channel is 8 bits.

On the other hand, in order to perform five-channel code division multiplexing, it is necessary to prepare five spreading codes. In the present embodiment, a cyclic extension code e1 is used for a pilot signal,
For the information signal, a combination of four cyclic extension codes selected from e2,..., E30 is used.

Here, in the present embodiment, the number of chips Q corresponding to the maximum permissible delay time of the delayed wave is 2, so that the difference between the cyclic shift numbers of the five cyclic extension codes included in the combination is at least Must be 2 + 1 bits.

Examples of combinations that satisfy such conditions include the following. (e1 e4 e7 e10 e13) (e1 e4 e7 e10 e14): (e1 e5 e8 e11 e14) (e1 e5 e8 e11 e15): (e1 e22 e25 e28 e31)

There are 4845 such combinations in total. Therefore, it is possible to transmit 12-bit information depending on which of these combinations is selected as the spreading code of each channel. 2 ¹² = 4096
≤ 4845.

Therefore, in this embodiment, 8+
12 = 20 bits of information can be transmitted.

Compared with a conventional communication system using cyclic extension codes, the difference between the cyclic shift numbers is at least 3
Is transmitted using 10 cyclic extension codes such that the following equation is satisfied. Therefore, when QPSK is used, 2 × (10−1) = 18 bits can be transmitted.

Therefore, according to the present embodiment, the transmission capacity can be made higher than that of the related art, while being not different from the related art in that it is hardly affected by the delay wave.

(Communication System) FIG. 2 is an explanatory diagram showing a schematic configuration of the communication system of the present embodiment. Hereinafter, description will be made with reference to this figure.

The communication system 201 includes a transmitting device 221
And a receiving device 241, both of which perform transmission by wireless communication.

At this time, as described above, 12-bit information is transmitted by selecting a combination of cyclic extension codes, and code division multiplexing of 5 channels is performed by using the cyclic extension code included in the combination as a spreading code. Transmits 8-bit information. In addition, information of 20 bits is transmitted per predetermined unit time.

(Transmission Apparatus) FIG. 3 is an explanatory diagram showing a schematic configuration of the transmission apparatus 221 of the present embodiment. Hereinafter, description will be made with reference to this figure.

The information (20 bits per unit time) transmitted by the transmitting device 221 is divided by the data divider 301 into 12-bit information and 8-bit information.

The M-sequence code generator 302 generates a basic code, the cyclic shift code generator 303 generates 31 cyclic codes c1, c2,..., C31, and the cyclic extension code generator 304 generates , E31,..., E31 are generated.

The code combination selector 305 outputs the divided 1
A combination of cyclic extension codes (five) associated with 2-bit information on a one-to-one basis is selected.

The divided 8-bit information is QPSK-modulated by the scramble circuit 306, and the serial-parallel converter 3
07 are parallelized into four channels.

A pilot signal 311 is assigned to the remaining one channel.

[0078] Five cyclic extension codes selected by the code combination selector 305 are assigned to each of the parallelized signals, and the spread spectrum is spread by the code spreader 308.

Further, the code division multiplexing circuit 309
The spread spectrum signal is multiplexed and transmitted from antenna 310 to receiving apparatus 241.

(Receiving Apparatus) FIG. 4 is an explanatory diagram showing a schematic configuration of the receiving apparatus 241 of the present embodiment. Hereinafter, description will be made with reference to this figure.

The signal received by antenna 401 is
Synchronization is achieved by the code synchronization circuit 402 using the pilot signal.

On the other hand, the M-sequence code generator 403 and the cyclic shift code generator 404 perform the same functions as the M-sequence code generator 302 and the cyclic shift code generator 303 of the transmitting device 221, and perform cyclic codes c1, c2, …, C31 is generated.

The correlator 405 calculates the correlation between each of the 31 generated cyclic codes c1, c2,..., C31 and the synchronized signal. Note that actually 30 cyclic codes c
2,…, c31 is sufficient. This is because the correlation with c1 is already used in the code synchronization circuit 402.

The radio wave propagation path estimating section 406 includes a correlator 405
Based on the result of the calculation, the influence of a delayed wave or the like is estimated.

The estimating section 407 calculates the calculated correlation result,
From the estimation result of the radio wave propagation path, the combination of the cyclic extension codes adopted in the transmitting device 221 is estimated.

The acquiring section 408 acquires 12-bit information associated with the estimated combination of cyclic extension codes on a one-to-one basis.

The Rake combining circuit 409 performs spectrum despreading using the estimated combination of the cyclic extension codes (five), the calculated correlation result, and the estimation result of the radio wave propagation path. When the serial signal is converted into a serial signal by the serial conversion unit 410, 8-bit information is obtained.

The data combiner 411 combines the 12-bit information and the 8-bit information, and restores and outputs the 20-bit information transmitted from the transmitting device 221.

(Combination of Codes) In the above embodiment, 5 was selected as the number of codes to be selected. However, other numbers of codes may be adopted. The following shows the relationship between the number C of codes to be selected, the number N of combinations thereof, and the maximum number B of bits that can be transmitted by using the M codes having a code length of 31 as a basic code. When C = 2, N = 26 and B = 4. When C = 3, N = 276 and B = 8. When C = 4, N = 1540 and B = 10. When C = 5, N = 4845, B = 12. When C = 6, N = 8548, B = 13. When C = 7, N = 8008 and B = 12. When C = 8, N = 3432, B = 11. When C = 9, N = 495 and B = 8.

Transmission can be performed according to the method of the present invention by employing such various combinations.

[0091]

As described above, according to the present invention,
A transmission capacity is high, a cyclic extension code combination generating apparatus, a transmitting apparatus, a receiving apparatus, a communication system, a transmitting method, a receiving method, which are suitable for realizing code division multiplexing communication which is less affected by delay waves and has a small number of parallel transmissions, Further, it is possible to provide an information recording medium on which a program for realizing these is recorded.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating a relationship between a cyclic extension code, a basic code, and a cyclic code according to a first embodiment of the present invention.

FIG. 2 is a schematic diagram showing a schematic configuration of a communication system in the embodiment.

FIG. 3 is a schematic diagram showing a schematic configuration of a transmission device in the embodiment.

FIG. 4 is a schematic diagram showing a schematic configuration of a receiving device in the embodiment.

[Explanation of symbols]

 Reference Signs List 101 cyclic extension code 102 basic code 103 cyclic code 201 communication system 221 transmitting device 241 receiving device 301 data divider 302 M-sequence code generator 303 cyclic shift code generator 304 cyclic extension code generator 305 code combination selector 306 scramble circuit 307 Serial-to-parallel converter 308 Code spreader 309 Code division multiplexing circuit 310 Antenna 311 Pilot signal 401 Antenna 402 Code synchronization circuit 403 M-sequence code generator 404 Cyclic shift code generator 405 Correlator 406 Radio channel estimator 407 Estimator 408 Acquisition Section 409 Rake synthesis circuit 410 Parallel / serial conversion section 411 Data synthesizer

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-2001-308823 (JP, A) JP-A-4-360434 (JP, A) JP-A-5-30079 (JP, A) JP-A-5-130068 (JP, A) JP-A-2000-354021 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H04J 13/04

Claims (17)

(57) [Claims] A basic code having a length of N bits is defined as 0, 1,.
A circulating unit that generates N codes that are circulated by N-1 bits; and for each of the generated N codes, the first L bits and the last J bits of the code, and the end of the code, A cyclic extension code, comprising: an extension unit that generates N cyclic extension codes added to the head; and a combination unit that generates 2 ^H combinations that select K cyclic extension codes from the N cyclic extension codes. A combination generating apparatus, wherein each of the generated 2 ^H combinations includes a cyclic extension code having the same number of cyclic bits, and for each of the generated 2 ^H combinations, the K included in the combination is included. A cyclic extension code combination generating apparatus characterized in that a difference between the number of cyclic bits of each of the cyclic extension codes is larger than a maximum allowable bit number Q of delay. 2. The method according to claim 1, wherein the basic code is a code included in any of an M sequence, a Gold code sequence, an orthogonal code sequence obtained from a Walsh function, or a Manchester-coded orthogonal sequence. 3. The cyclic extension code combination generation device according to item 1. 3. A division unit that divides W-bit information to be transmitted into H-bit information and WH-bit information, and is generated by the cyclic extension code combination generating apparatus according to claim 1 or 2. From the combination of 2 ^H cyclic extension codes,
A selector for selecting a combination of cyclic extension codes associated with the divided H-bit information on a one-to-one basis; and combining the divided WH bit information with the selected cyclic extension code. A code division multiplexing unit that performs code division multiplexing on the K cyclic extension codes included in the information as a spread code, and a transmission unit that transmits the code division multiplexed information. 4. The code division multiplexing unit uses a cyclic extension code having the same number of cyclic bits included in any of the 2 ^H cyclic extension codes as a spreading code for a pilot signal. Item 4. The transmitting device according to item 3. 5. A receiving section for receiving information transmitted from the transmitting apparatus according to claim 3 or 4, wherein N is a basic code having a length of N bits circulated by 0, 1,..., N-1 bits. From the K codes, a combination of K codes having a high correlation with the received information is selected, and it is estimated that the K cyclic extension codes corresponding to the combination are used as spreading codes for code division multiplexing. An estimating unit, an obtaining unit that obtains H-bit information associated with the estimated K code combinations on a one-to-one basis, and the estimated K code combinations as despread codes. A restoring unit for restoring W-H bit information from the received information; the acquired H-bit information;
An output unit that outputs W-bit information obtained by combining the H-bit information and the transmitted information as transmitted information. 6. A communication system comprising: the transmission device according to claim 3 or 4; and the reception device according to claim 5, which receives information transmitted from the transmission device. 7. A basic code having a length of N bits is defined as 0, 1,.
A circulating step of generating N codes that are circulated by N-1 bits; and for each of the generated N codes, the first L bits and the last J bits of the codes, A cyclic extension code comprising: an extension step of generating N cyclic extension codes added to the head; and a combination step of generating 2 ^H combinations for selecting K cyclic extension codes from the N cyclic extension codes. A combination generation method, wherein each of the generated 2 ^H combinations includes a cyclic extension code having the same number of cyclic bits, and for each of the generated 2 ^H combinations, a K included in the combination is included. A method for generating a combination of cyclic extension codes, wherein a difference between the number of cyclic bits of each of the plurality of cyclic extension codes is larger than a maximum allowable bit number Q of delay. 8. The system according to claim 7, wherein the basic code is a code included in any of an M sequence, a Gold code sequence, an orthogonal code sequence obtained from a Walsh function, or a Manchester-coded orthogonal sequence. 3. The method for generating a combination of cyclic extension codes according to item 1. 9. A division step of dividing W-bit information to be transmitted into H-bit information and W-H-bit information, and a method of generating a cyclic extension code combination according to claim 7 or 8. From the combination of 2 ^H cyclic extension codes,
A selection step of selecting a combination of cyclic extension codes associated with the divided H-bit information on a one-to-one basis; and combining the divided WH bit information with the selected cyclic extension code. A code division multiplexing step of code division multiplexing the K cyclic extension codes included in the information as a spread code, and a transmission step of transmitting the code division multiplexed information. 10. The code division multiplexing step, wherein a cyclic extension code having the same number of cyclic bits included in any of the 2 ^H cyclic extension code combinations is used as a spreading code for a pilot signal. Item 10. The transmission method according to Item 9. 11. A receiving step of receiving information transmitted by the transmission method according to claim 9 or 10, wherein N is a basic code having a length of N bits circulated by 0, 1,..., N-1 bits. From the K codes, a combination of K codes having a high correlation with the received information is selected, and it is estimated that the K cyclic extension codes corresponding to the combination are used as spreading codes for code division multiplexing. An estimation step, an acquisition step of acquiring H-bit information associated with the estimated K code combinations on a one-to-one basis, and a despread code using the estimated K code combinations as: Restoring W-H bit information from the received information; and acquiring the acquired H-bit information;
An output step of outputting the W-bit information obtained by combining the H-bit information and the transmitted information as transmitted information. 12. A computer (digital signal processing hardware, DSP (Digital Signal Processor), FP)
Includes GA (Field PrograJJable Gate Array). )
, A cyclic unit that generates N codes obtained by circulating a basic code having a length of N bits by 0, 1,..., N−1 bits, for each of the generated N codes, a leading L of the code An extension unit that generates N cyclic extension codes by adding the bit and the end J bit to the end and the beginning of the code, respectively, and selects K cyclic extension codes from the N cyclic extension codes A program that functions as a combination unit that generates 2 ^H combinations, wherein each of the generated 2 ^H combinations includes a cyclic extension code having the same number of cyclic bits, and the generated 2 ^H combinations For each of K, the difference between the number of cyclic bits of the K cyclic extension codes included in the combination is made to be larger than the maximum allowable bit number Q. Data readable information recording medium. 13. The computer program according to claim 1, wherein the basic code is a code included in any of an M sequence, a Gold code sequence, an orthogonal code sequence obtained from a Walsh function, or a Manchester-coded orthogonal sequence. 13. The information recording medium according to claim 12, wherein the information recording medium functions as follows. 14. A computer (digital signal processing hardware, DSP (Digital Signal Processor), FP
Includes GA (Field PrograJJable Gate Array). )
A division unit for dividing W-bit information to be transmitted into H-bit information and W-H-bit information, wherein the program recorded on the information recording medium according to claim 12 or 13 is transmitted to another computer. A selecting unit that selects a combination of cyclic extension codes associated with the divided H-bit information on a one-to-one basis from a combination of 2 ^H cyclic extension codes generated by the execution; A code division multiplexing unit for code division multiplexing W-H bit information as a spreading code using K cyclic extension codes included in the selected combination of cyclic extension codes; and transmitting the code division multiplexed information. A computer-readable information recording medium on which a program is recorded, the information recording medium functioning as a transmitting unit that performs the operation. 15. The computer program according to claim 1, wherein the code division multiplexing unit transmits a cyclic extension code having the same number of cyclic bits included in any of the 2 ^H cyclic extension codes to a pilot signal. The information recording medium according to claim 14, wherein the information recording medium is made to function as a computer. 16. A computer (digital signal processing hardware, DSP (Digital Signal Processor), FP)
Includes GA (Field PrograJJable Gate Array). )
A receiving unit for receiving information transmitted by executing the program recorded on the information recording medium according to claim 14 or 15 on another computer, wherein the basic code having a length of N bits is 0, 1, or .., A combination of K codes having a high correlation with the received information is selected from the N codes circulated by N-1 bits, and the K cyclic extension codes corresponding to the combination are code-divided. An estimating unit for estimating that the estimated K code has been used as a multiplexed spreading code; an acquiring unit for acquiring H-bit information associated with the estimated K codes in a one-to-one correspondence; A restoring unit that restores W-H bit information from the received information by using a combination of codes as a despread code; and the acquired H-bit information and the restored W-bit information.
A computer-readable information recording medium on which a program is recorded, which functions as an output unit that outputs W-bit information obtained by combining H-bit information and transmitted information. 17. The information recording medium according to claim 12, wherein the information recording medium is a compact disk, a floppy (registered trademark) disk, a hard disk, a magneto-optical disk, a digital video disk, a magnetic tape, or a semiconductor memory. The information recording medium according to any one of the above items.