KR100396506B1 - Double ochma device and method therefor - Google Patents

Abstract

PURPOSE: A double OCHMA(Orthogonal Code Hopping Multiple Access) device and a method therefor are provided to assign a hopping pattern of an orthogonal code series to each channel and classify channels. CONSTITUTION: A transmitter has a hopping control unit(400), code hopping units(420), an adder(430) and a band spreader(440). The hopping control unit(400) generates a transmission hopping code generating signal and a transmission hopping code selecting signal for hopping a double orthogonal code in a set of double orthogonal codes defined for classifying channels of transmitted digital signals according to a set certain sequence. The code hopping units(420) generate hopped double orthogonal codes under the control of the hopping control unit(400), and spread digital signals of corresponding channels by the double orthogonal codes. The adder(430) adds the outputs of the code hopping units(420). The band spreader(440) spreads the output of the adder(430) by PN(Pseudo Noise) codes. A receiver has a hopping control unit, a band despreader and code inverse hopping units. The hopping control unit generates a reception hopping code generating signal and a reception hopping code selecting signal for hopping a double orthogonal signal in a set of double orthogonal codes defined for inversely hopping digital signals of a reception channel according to a set certain sequence. The band despreader despreads a receiving signal by a PN code. The code inverse hopping units generate a double orthogonal code which is equally hopped with a hopping double orthogonal code mixed in received channels under the control of the hopping control unit, despread the output of the band despreader, and recover the digital signal.

Description

Dual Orthogonal Code Hopping Multiple Access Device and Method

The present invention relates to a transceiver and a method of a spread spectrum multiple access communication system, and more particularly, to a transceiver and a method of a spread spectrum multiple access communication system employing a dual orthogonal code hopping scheme.

1 shows a configuration of a transmitter in a multiple communication system using a conventional orthogonal code, and FIG. 2 shows a configuration of a receiver in a multiple communication system using a conventional orthogonal code. 3 is a diagram illustrating operating characteristics of the communication system as shown in FIGS. 1 and 2.

Referring to FIG. 1, an orthogonal code generator (OCG) 10 is configured with a number corresponding to a number of channels, so that different orthogonal codes can be supplied to information data 0-m input to each input channel. do. The orthogonal code may be a Walsh, Hadamard, or Gold sign. Mixer 11 is composed of a number corresponding to the number of information data to be input, each one of the mixers respectively input the corresponding information data and the output of the quadrature code generator 10, and outputs the two inputs mixed. Therefore, the mixer 11 synthesizes and outputs an orthogonal code to corresponding information data. The adder 12 adds and outputs synthesized data respectively output to the mixer 11. A pseudo noise sequence generator (PNSG) 13 generates a PN sequence for spreading the output signal. Mixer 14 spreads the output of the adder 12 and the PN sequence by mixing. The modulator 15 modulates the signal output from the mixer 14 into an RF signal and outputs the modulated signal. The power amplifier 16 amplifies the power of the RF signal output from the modulator 15 and outputs the power through the antenna 17.

2 illustrates that the reception amplifier 21 amplifies an RF signal received through the antenna 20. The demodulator 22 demodulates and outputs the signal output from the reception amplifier 21. PN sequence generator (PNSG) 23 generates a PN sequence for despreading the spread spectrum signal. The mixer 24 mixes and despreads the output of the demodulator 22 and the PN sequence. Orthogonal code generator 28 is composed of a number corresponding to the number of channels, each generates a different orthogonal code. The orthogonal code may be a Walsh, Hadamard, or Gold sign. The mixer 25 has a number corresponding to the number of channels, and each mixer inputs the corresponding channel data and the output of the quadrature code generator 28, respectively, and mixes the two inputs. Therefore, the mixer 25 combines orthogonal codes with corresponding channel data and restores the original channel data. The integrator 26 adds the data output from the mixer 25 and outputs the information data 0-m of the corresponding channel.

The communication system as shown in FIGS. 1 and 2 operates as shown in FIG. 3. It is assumed that the information data input in FIG. 3 is two channels ch1 and ch2, and the orthogonal codes used are Walsh codes as shown in Table 1 below.

TABLE 1

1, 3, and Table 1, it is assumed that information data 0 input to channel ch1 is equal to 311, and information data 1 input to channel ch2 is equal to 312. In the mixer 11, the information data and the orthogonal code are mixed. The information data 0 is mixed with the orthogonal code w (0) and converted into a signal of chO * w (0) as shown in 313. The information data 1 is orthogonal code w ( 1) and converted to a signal of ch1 * w (0) as shown in 314. Information mixed with the orthogonal code as shown in 313 and 314 is added by the adder 12 and converted into a signal of ch0 * w (0) + ch1 * w (1) as shown in 315. The signal, such as 315, is mixed with the PN sequence in the mixer 14 and spread out, and then modulated into an RF signal through the modulator 15 and output.

2, 3 and <Table 1>, the RF signal output from the transmitter is mixed with the PN sequence in the mixer 24 to be despread, and the signal at this time is ch0 * w (0) equal to 315. It becomes a signal of + ch1 * w (1). Mixer 25 restoring the output of channel ch0 then mixes orthogonal code w (0) with a signal such as 315 output from synthesizer 24, such that {ch0 * w (0) + ch1 * w (1)} * equal to 321. A signal w (0) is generated, and the integrator 26 of the channel ch0 integrates this to restore and output information data of the channel ch0 such as 322. In addition, the mixer 25 restoring the output of the channel 1 mixes an orthogonal code w (1) and a signal such as 315 output from the synthesizer 24, such that {ch0 * w (0) + ch1 * w (1)} equal to 323. Generates a * w (1) signal, and integrator 26 of channel ch1 integrates this to restore and output information data of channel ch1 such as 324.

However, a communication system using the conventional spread spectrum multiple access scheme as described above must synthesize a specific orthogonal code for distinguishing each channel when multiple channels are simultaneously connected and transmitted to the same transmission medium. That is, in the conventional spread spectrum multiple access scheme in which channels are divided using orthogonal codes, only one orthogonal code belonging to a set of orthogonal codes defined for distinguishing channels is allocated to each channel, and the allocated orthogonal codes are repeatedly transmitted. Synthesize into information data to be desired. As described above, when the same orthogonal codes are repeatedly multiplied, the orthogonal codes corresponding to the number of channels should be provided, and the power density is not evenly distributed in the frequency spectrum.

Accordingly, an object of the present invention is to provide an apparatus and method for transmitting and receiving devices to distinguish channels by assigning a hopping pattern of an orthogonal code string to each channel in a communication system using a spread spectrum multiple access method.

Another object of the present invention is to divide and multiply each channel according to a pattern in which a double orthogonal code hops by multiplying by changing a double orthogonal code in a set of double orthogonal codes according to a random sequence in a communication system using a spread spectrum multiple access scheme. It is to provide a communication device and method that can improve the function.

In order to achieve the above object, the present invention provides a communication apparatus using a hop orthogonal code multiple access scheme, in which a dual orthogonal code in a set of double orthogonal codes defined to distinguish a channel of transmitted digital signals is leaped according to a predetermined sequence. While mixing with the digital signal of the corresponding channel, and adding and outputting the signal of each channel, and receiving the added signal and hoping according to the jump pattern used in the transmitter of the corresponding channel, a double orthogonal code is added to the signal. It is characterized by consisting of a receiver for recovering the digital signal by multiplying.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a diagram showing the configuration of a transmission apparatus of a spread spectrum multiple access communication system using a conventional orthogonal code.

2 is a diagram illustrating a configuration of a receiver of a spread spectrum multiple access communication system using a conventional orthogonal code.

3 is a waveform diagram showing characteristics of a spread spectrum multiple access communication system using a conventional orthogonal code;

4 is a block diagram illustrating a transmission apparatus of a spread spectrum multiple access communication system employing a dual orthogonal code hopping scheme according to an embodiment of the present invention.

FIG. 5 is a diagram illustrating a receiver configuration of a spread spectrum multiple access communication system employing a dual orthogonal code hopping scheme according to an embodiment of the present invention.

FIG. 6 shows an example in which an orthogonal code used in a double orthogonal code hopping scheme is a Walsh orthogonal code.

FIG. 7 shows an example in which an orthogonal code used in a double orthogonal code hopping method is a Hadamard orthogonal code.

8 is a waveform diagram showing characteristics of a spread spectrum multiple access communication system employing a double orthogonal code hopping scheme according to an embodiment of the present invention;

Using Orthogonal Code Hopping Multiple Access (OCHMA), each channel allows a method of multiplying different orthogonal codes according to a hop pattern without fixing orthogonal codes multiplied to each channel while maintaining orthogonality. . As described above, when the PN sequence is not multiplied after the spread by the orthogonal code hopping, or when the PN sequence can be removed in synchronization with the side to be tapped when multiplied, the following problems occur.

If the transmitting party to be eavesdropped knows the size and type of the orthogonal code used and knows the starting point and the end point of each orthogonal code, even if the hopping pattern of the orthogonal code is not known, the receiver reaches the chip unit of each orthogonal code. If the orthogonal code is leap if we can accurately distinguish, we can determine the value before the orthogonal code is multiplied by examining the value of a particular chip.

Table 2 below shows an example of the Walsh code, and Table 3 shows an example of the Adamard code.

TABLE 2

TABLE 3

Referring to Tables 2 and 3, when an orthogonal code having a size of N is created, one value can always be made the same as a sign indicated by a bold of Table 2. In addition, when creating an orthogonal code of size N, if the code of the first chip is different as indicated by the bold shown in Table 3, the code of each chip of all the corresponding orthogonal codes underlined is changed [* -1]. While maintaining the orthogonality of Equation 1, the first chip has the same value.

[Equation 1]

In the case of the above example, it is possible to know what the original bit value was by determining only the sign of the value corresponding to the position of the first chip without considering other chip values. Therefore, it is preferable to use a pair of orthogonal codes wherever possible so that the orthogonal codes do not have the same value at any position.

An embodiment of the present invention proposes a communication apparatus and method using a double orthogonal code hopping scheme that can improve security in any situation.

4 illustrates a configuration of a transmitter of a communication system using a double orthogonal code hopping scheme according to an embodiment of the present invention.

Referring to FIG. 4, the hopping controller 400 generates a hopping control signal for outputting an orthogonal code for digital signal sources of each channel according to a defined hopping scheme. The jump controller 400 generates a jump control signal corresponding to the number of transmission channels. The hopping control unit 400 generates a hopping code generation signal and a hopping code selection signal by changing a double orthogonal code in a set of double orthogonal codes defined for each channel according to an arbitrary sequence. Digital signal source 410 corresponds to the number of channels.

The sign leap 420 is configured with a number corresponding to the number of the digital signal sources 410. Looking at the configuration of each code hopping unit 420, an orthogonal code generator (OCG) 421 is orthogonal code OC (Hx) corresponding to the hopping code generation signal of the corresponding channel in the hopping control unit 400 (where x Corresponds to the channel number). The inverter 422 multiplies the generated orthogonal code OC (Hx) by " -1 " to generate a / OC (Hx) having a changed sign. The switch 423 inputs the orthogonal codes OC (Hx) and / OC (Hx), and selectively outputs the orthogonal codes among the two input signals by the hopping code selection signal output from the hopping control unit 400. The multiplier 424 mixes the signal source of the corresponding channel at the output of the digital signal source 410 and the orthogonal code output from the switch 423 and synthesizes the signal source with the hop code. Therefore, the multiplier 424 is a channel spreader, and the signal output from the multiplier 424 is a channel spread signal with a hopped double orthogonal code. Here, the quadrature code generator 421, the inverter 422, and the switch 423 are dual quadrature code generators.

The adder 430 adds and outputs a signal output from the code jumper 420 of each channel. The spread spectrum unit 440 includes a PN sequence generator 441 and a synthesizer 442. The PN sequence generator 441 generates a PN sequence for spreading the bandwidth of the transmission signal. The mixer 442 synthesizes and outputs the output of the adder 430 and the PN sequence. Thus, the multiplier 442 becomes a PN spreader. The transmitter 450 includes a modulator, a filter, and an amplifier, and converts a transmission signal into an RF signal and outputs the RF signal.

5 is a block diagram of a receiver of a communication system using a double orthogonal code hopping scheme according to an exemplary embodiment of the present invention.

Referring to FIG. 5, the receiver 510 includes a demodulator, a filter, and amplifiers, and converts the received RF signal into a baseband signal. The inverse spreader 540 includes a PN sequence generator 521 and a synthesizer 522. The PN sequence generator 521 generates a PN sequence for despreading a spread signal. The mixer 522 synthesizes the receiver 510 and the PN sequence to generate a despread signal.

The hopping controller 500 generates a hopping control signal for outputting an orthogonal code for digital signal sources of each channel according to a defined hopping scheme. The hopping control unit 500 generates a hopping code generation signal and a hopping code selection signal by changing a double orthogonal code in a set of double orthogonal codes defined for each channel according to an arbitrary sequence. The hopping control signal of the hopping control unit 500 of the receiving apparatus should be the same as the hopping control signal of the hopping control unit 400 of the transmitting apparatus corresponding to the receiving channels. That is, the hopping control signal of the hopping control unit 500 should have the same value as the hopping control signal of the hopping control unit 400 of the corresponding channel.

The code reverse jumper 530 includes a number corresponding to the number of the digital signal sources 540. Looking at the configuration of each code hopping unit 530, an orthogonal code generator 531 is orthogonal code OC (Hx) corresponding to the hopping code generation signal of the corresponding channel in the hopping control unit 500 (where x corresponds to the channel number). Occurs. The inverter 532 multiplies the generated orthogonal code OC (Hx) by " -1 " to generate a / OC (Hx) having a changed sign. The switch 533 inputs the orthogonal codes OC (Hx) and / OC (Hx), and selects and outputs a corresponding orthogonal code among the two input signals by the hopping code selection signal output from the hopping control unit 500. The multiplier 534 mixes the output of the inverse spreader 520 and the orthogonal code output from the switch 533. Here, the orthogonal code generator 531, the inverter 532, and the switch 533 are double orthogonal code generators. Also, the multiplier 534 is a channel despreader, and the signal output from the multiplier 534 becomes a channel despread signal with a hopped double orthogonal code. Integrator 535 integrates the output of multiplier 534 to restore the digital signal source of the corresponding channel.

The digital signal destination 540 outputs the digital signals output from the code reverse jumper 530 of the corresponding channels to the corresponding channel.

4 and 5, it is one of multiple access schemes in which the transmitting side simultaneously transmits a plurality of digital signals through one communication channel and the receiving side selects only a desired signal. In an embodiment of the present invention, a hop pattern of a double orthogonal code is used to distinguish channels in a transmitter and a receiver. Orthogonal Code Hopping Assume that the set of orthogonal codes used in the multiple access scheme is {OC (1), OC (2), OC (3), ..., OC (N)}. The set of signs is {OC (1), / OC (1), OC (2), / OC (2) OC (3), / OC (3), ..., OC (N), / OC (N )}. "/" In the set is the original orthogonal code multiplied by "-1", which is a signal that has logically passed through the inverter gate.

The sign jump unit 420 is provided with a number corresponding to the number of channels as described above, and each sign jump unit 420 is generated and selected by a jump control signal outputting a digital signal source of a corresponding channel from the jump controller 400. The product is multiplied by an orthogonal code, and thus the corresponding channel is distinguished from other channels. Also, the orthogonal code generated by the code reverse leap 420 should be the same as the orthogonal code multiplied by the corresponding channel at the time of transmission. That is, the hopping control signals of the same channels output from the hopping control unit 400 of the transmitting apparatus and the hopping control unit 500 of the receiving apparatus should be the same.

6 and 7 show examples of the dual orthogonal code hopping multiple access scheme, which is an example of the configuration of the code hopping unit 420. 6 and 7 select orthogonal codes to be mixed by the same hopping control signals output from the hopping control units 400 and 500 promised between the transmitter and the receiver. At this time, any two hop patterns used by the transmitting side should not include the same orthogonality at a specific time to prevent collision.

8 is a view for explaining the operation characteristics of the communication communication device of the dual orthogonal code hopping multiple access method according to an embodiment of the present invention. The information data input in FIG. 8 is assumed to be two channels ch1 and ch2, and the orthogonal code used is assumed to be the Walsh code as shown in Table 4 below.

TABLE 4

4, 5, and Table 4, it is assumed that information data 0 input to channel ch1 is equal to 811, and information data 1 input to channel ch2 is equal to 812. Here, the hop orthogonal code of ch1 jumps in the order of w (0), w (1), / w (3), w (2), and the hop orthogonal code of ch2 is w (1), / w (2), Assume that we hop in the order of w (2), w (1). As described above, the orthogonal codes can be set in duplicate according to each channel, and the hopping control unit 400 outputs the hopping control signal for generating and selecting the double orthogonal codes set as described above.

Then, the code jump unit 420 of the channel ch1 receives the jump code generation signal output in the order of w (0), w (1), w (3), and w (2) output from the jump controller 400. A jump code selection signal for switching in the order of 1101 is generated. The orthogonal code generator 421 then generates the w (0), w (1), w (3), w (2) and switch 423 selects the output of inverter 422 at the w (3) orthogonal code position. Therefore, the hop orthogonal codes input to the multiplier 424 are w (0), w (1), / w (3) and w (2) (hereinafter referred to as H0). Also, the code jump unit 420 of the channel ch2 receives the jump code generation signal output in the order of w (1), w (2), w (2), and w (1) output from the jump controller 400. Generates a hopping code selection signal for switching in the order of 1011. Then, the quadrature code generator 421 generates the w (1), w (2), w (2), and w (1), and the switch 423 outputs the output of the inverter 422 at the w (2) orthogonal code position located in front. Choose. Accordingly, the hop orthogonal codes input to the multiplier 424 are w (1), / w (2), w (2), and w (1) (hereinafter referred to as H1).

Then, the multiplier 424 mixes the information data and the hopping orthogonal code. The information data 0 is mixed with the hopping orthogonal code H0 of the channel ch1 and converted into a signal of ch0 * H0 as shown in 813, and the information data 1 is the hopping orthogonal code H1. And then converted into a signal of ch1 * H1 as shown in 814. Information mixed with the hop orthogonal code as shown in 813 and 814 is added by the adder 430 and converted into a signal of ch0 * H0 + ch1 * H1 as shown in 815. The signal, such as 315, is mixed with the PN sequence in the mixer 14 and spread out, and then modulated into an RF signal through the modulator 15 and output.

In addition, the RF signal output from the transmitting apparatus is despread by being mixed with the PN sequence in the inverse spreader 520, and the signal at this time becomes a signal of ch0 * H0 + ch1 * H1 such as 815. At this time, the hopping control signal output by the hopping control unit 500 of the receiving apparatus should be the same as the hopping control signal output from the hopping control unit 400 of the transmitting apparatus. That is, the double orthogonal code mixed in the channel received by the receiving device should be the same as the double orthogonal code of the transmitting device.

Accordingly, the hopping orthogonal code output from the code inverse leap 530 of the channel ch1 is H0, and the hopping orthogonal code output from the code inverse leap 530 of the channel ch2 is H1. The mixer 25 restoring the output of the channel ch0 then mixes the hopping quadrature code H0 with a signal such as 815 output from the inverse spreader 520 to generate a ch0 * H0 + ch1 * H0 signal such as 821, integrating the channel ch1. The 535 integrates this and restores and outputs the information data of the channel ch0 such as 822. Also, a multiplier 534 for restoring the output of the channel ch1 mixes a hopping orthogonal code H1 and a signal such as 815 output from the inverse spreader 520 to generate a ch0 * H1 + ch1 * H1 signal such as 823. Integrator 535 integrates this to restore the information data of channel ch1 such as 824.

As described above, the dual orthogonal code hopping multiple access scheme according to the embodiment of the present invention has the same spreading gain and can be selected for each orthogonal code in two cases. Can improve the sex.

Claims (11)

In the dual orthogonal code hopping transmission method of a communication system using a multiple access method, To generate a double orthogonal code while jumping a double orthogonal code in a set of double orthogonal codes defined to distinguish channels of digital signals to be transmitted, according to a set random sequence, and to spread the digital signal of the channel to the generated double orthogonal code. Transmitting process, A dual orthogonal code hopping multiple access method comprising receiving a signal in which the multiple channel signals are combined and leaping in the same manner as a transmitter hopping double orthogonal code of a corresponding channel while restoring a digital signal spread by the double orthogonal code. Communication device using the scheme. In a spread spectrum communication apparatus using a dual orthogonal code hopping multiple access scheme, Transmitter, A transmission hopping control unit for generating a transmission hopping code generation signal and a transmission hopping code selection signal for hopping a double orthogonal code in a set of double orthogonal codes defined according to a predetermined sequence to distinguish channels of digital signals to be transmitted; A code jumper which is formed of a number corresponding to the number of transmission channels, generates a double orthogonal code that is weakened under the control of the transmission hopping controller, and spreads digital signals of corresponding channels to the double orthogonal code; An adder for adding outputs of the code hop units; A spreader configured to spread the output of the adder with a PEN code, Receiver, A reception hop control unit for generating a reception hopping code generation signal and a reception hopping code selection signal for hopping a double orthogonal code within a set of double orthogonal codes defined according to a predetermined sequence to reverse hop digital signals of a reception channel; A reverse band spreader for despreading the received signal with a PEN code; Code reciprocal to recover the digital signal by despreading the output of the inverse spreader to the double orthogonal code while generating a double orthogonal code that leaps equal to the hop double orthogonal code synthesized to the received channels under the control of the reception hop controller. A spread spectrum communication device using a dual orthogonal code hopping multiple access scheme, characterized in that consisting of weak parts. The method of claim 2, wherein the sign leap, A transmission orthogonal code generator for generating an orthogonal code of a corresponding channel that hops an orthogonal code in an orthogonal code set defined by the transmission code hopping signal according to a predetermined sequence; An inverter for generating a double orthogonal code by changing an output code of the transmission orthogonal code generator, respectively; Switches for outputting the output of the transmitting quadrature code generator and the coded orthogonal code by the hopping code selection signal; And a multiplier for channel spreading by multiplying an input signal source of a corresponding channel by an orthogonal code selected by the switch. The method according to claim 2 or 3, The receiver, A reception orthogonal code generator for generating an orthogonal code of a corresponding channel that hops an orthogonal code in a prescribed set of reception channels according to a predetermined sequence by the reception hopping code generation signal; An inverter for generating a double orthogonal code by changing the output code of the received orthogonal code generator, A reception switch for switching the output of the reception quadrature code generator and the quadrature code having been changed by the reception hopping code selection signal; A multiplier for despreading a channel by multiplying the output of the inverse spreader by an orthogonal code selected by the switch; And an integrator for integrating the output of the multiplier and restoring the received signal. A communication method of a spread spectrum communication system using a double orthogonal code hopping multiple access scheme, A transmission code hopping step of generating a double orthogonal code for leaping a double orthogonal code in a set of double orthogonal codes defined according to a predetermined random sequence to channel spread digital signals of corresponding channels by dividing a channel of digital signals to be transmitted. And a transmission process comprising adding the transmitted code-bound signals and spreading the band by mixing the addition output and the P & N code; Inversely spreading by mixing the received signal and the P & N code and transmitting a double orthogonal code that hops a double orthogonal code in a set of double orthogonal codes according to a predetermined sequence to reverse leap the digital signals of the reception channel. And a code inverse hopping step of recovering the digital signal by channel despreading of the inverse spread spectrum signal. The method of claim 5, wherein the transmission code hopping step, A transmission orthogonal code generation step of generating an orthogonal code of a corresponding channel that hops an orthogonal code in the prescribed orthogonal code set according to a set arbitrary sequence; Generating a double orthogonal code by changing a sign of the transmission orthogonal code; Switching the transmission orthogonal code and the coded orthogonal code by the hopping code selection signal; And spreading the input signal source of the corresponding channel to the orthogonal code outputted from the switch. 2. The communication method of a spread spectrum communication system using a double orthogonal code hopping multiple access method. The method according to claim 5 or 6, The received code reverse leap step, A receiving orthogonal code generation step of generating an orthogonal code of a corresponding channel that hops an orthogonal code in a prescribed set of receiving channels according to a set arbitrary sequence; Generating a double orthogonal code by changing the sign of the received orthogonal code; Switching outputting the received orthogonal code and the code changed orthogonal code; Channel despreading the inverse spread signal with the orthogonal code output from the switch; And recovering the received signal by integrating the channel despread signal. In the transmitter of a mobile communication system using a code division multiple access method, A jump control unit for generating a signal for controlling the generation and selection of a leap code for generating an orthogonal code that leaps orthogonal codes within a prescribed set according to a set arbitrary sequence; A dual orthogonal code generator for generating a double orthogonal code by the jump control signal; An orthogonal code multiplier for multiplying and transmitting the transmitted signal by the generated orthogonal code; And a PN multiplier for multiplying the output of the orthogonal code multiplier by the PN code. The method of claim 8, wherein the orthogonal code generator, An orthogonal code generator for generating an orthogonal code corresponding to the hopping code generation signal; An inverter for generating a double orthogonal code by inverting the sign polarity of the generated orthogonal code; And a switch configured to select an output of the quadrature code generator or the inverter as an orthogonal code according to the hopping code selection signal. A code division multiple access method that receives a signal from a transmitting device that spreads a digital signal of a corresponding channel while leaping a double orthogonal code in a set of double orthogonal codes defined to distinguish channels of digital signals to be transmitted, according to a set arbitrary sequence. In the receiving apparatus of the mobile communication system using a, A PN multiplier for multiplying the received signal by a PN code to despread it; A jump control unit for generating a signal for controlling the generation and selection of a hop code coincident with the transmitting device to generate an orthogonal code that hops an orthogonal code within a prescribed set according to a set arbitrary sequence; A dual orthogonal code generator for generating a double orthogonal code by the jump control signal; And an orthogonal code multiplier for despreading by multiplying the signal output from the PN multiplier by the generated double orthogonal code. The method of claim 10, wherein the orthogonal code generator, An orthogonal code generator for generating an orthogonal code corresponding to the hopping code generation signal; An inverter for generating a double orthogonal code by inverting a sign of the generated orthogonal code; And a switch configured to select an output of the quadrature code generator or the inverter as an orthogonal code according to the hopping code selection signal.

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