KR20040094048A - Method of Generating a Public Long Code Mask Using at a Mobile Communication System - Google Patents

Abstract

PURPOSE: A method for generating a public long code mask in a mobile communication system is provided to generate a public long code mask by using an MEID(Mobile Equipment Identifier), thereby generating the public long code mask and a public long code without an ESN(Electronic Serial Number). CONSTITUTION: A system receives a type value of a public long code mask through a message. If the type of the received public long code mask is an existing type, the system sets least significant bits received through an ECAM(Extended Channel Assignment Message) to least significant bits of the public long code mask. If the type of the received public long code mask is a new type, the system maps the least significant bits of the public long code mask from an MEID, and generates the mapped least significant bits of the public long code mask.

Description

Method of Generating a Public Long Code Mask Using at a Mobile Communication System}

The present invention relates to a method for generating a public long code mask in a mobile communication system.

In a CDMA 2000 communication system, long codes are used to encrypt the forward channel in the forward channel and to determine the location of the power control bits. In addition, the long code serves to distinguish each terminal in a reverse channel, and serves to reduce interference with each terminal and other subscriber stations.

The long code consists of 42 bits. 1 is a block diagram illustrating a process of generating the long code in general.

As shown in FIG. 1, the long code is generated according to a 42-bit long code mask format, and the generated long code is a transmission signal X and a modulo-2 inner product. Play the roles described above.

The long code mask format is generated differently for each channel. On the other hand, the common channels are named as a long code mask format, but the traffic channels are named as a public long code mask format in general. Among the traffic channels, when a voice signal is encrypted, the traffic signal is named as a private long code mask format.

The long code mask is generated differently for each channel, and the public long code mask format used for the traffic channel is illustrated in FIGS. 2 and 3.

FIG. 2 is a diagram illustrating a public long code mask format for a reverse fundamental channel and a reverse supplemental code channel having a radio configuration (RC) of 1 or 2. FIG.

3 shows a reverse fundamental channel, a reverse supplemental channel, a reverse dedicated control channel, and a forward fundamental channel having the radio configuration (RC) of 3, 4, 5, and 6; Forward Fundamental Channel, Forward Supplemental Control Channel, Forward Supplemental Channel, Forward Dedicated Control Channel, Forward Packet Data Channel This diagram shows the public long code mask format for.

As shown in FIGS. 2 and 3, the Public Long Code Mask (PLCM) format includes PLCM_37 (M36 to M0) consisting of 37 bits of least significant bit (LSB). The PLCM_37 (M36 to M0) may be further divided into first least significant bits M36 to M32 and second least significant bits M31 to M0 that are lower than the first least significant bits. In FIG. 2, the code channel index i indicates three bits M39 to M37 that are higher than the first least significant bits. In the code channel index i, '000' indicates a reverse fundamental channel, and '001' to '111' indicate a reverse supplemental control channel i (i = 1, 2, , 6,7).

On the other hand, the base station should inform the terminal how the terminal generates the second least significant bits (M31 ~ M0) of the public long code mask through an Extended Channel Assignment Message (ECAM).

In other words, if the type (PLCM_TYPE) of the public long code mask composed of 4 bits received from the base station through the Extended Channel Assignment Message (ECAM) is '0000', the terminal is assigned to the first least significant LSB (Least Significant). Bit) 5 bits M36 to M32 are set to '11000', and the second least significant 32 bits M31 to M0 correspond to an Electronic Serial Number (ESN) as follows. It is created by permutation.

For example, the electronic serial number ESN and the second least significant bits M31 to M0 may be represented by the following equations (1) and (2).

ESN = {E31, E30, E29,, E2, E1, E0} (1)

M31 ~ M0 = {E0, E31, E22, E13, E4, E26, E17, E8, E30, E21, E12, E3, E25, E16, E7, E29, E20, E11, E2, E24, E15, E6, E28 , E19, E10, E1, E23, E14, E5, E27, E18, E9} (2)

If the type of the public long code mask (PLCM_TYPE) consisting of the four bits received through the extended channel assignment message (ECAM) is '0001', the terminal is the first of the public long code mask (Public Long Code Mask) '11011' is set as 1 least significant 5 bits (M36 to M32), and the second least significant bits (M31 to M0) are 32 bits received from the base station through the extended channel allocation message (ECAM). 2 Set to the value of the least significant 32 bits (PLCM_32).

The electronic serial number (ESN) is an identifier uniquely assigned to the terminal in the CDMA 2000 communication system and used for call processing.

4 is a diagram showing the structure of the electronic serial number (ESN) consisting of 32 bits.

As shown in FIG. 4, the electronic serial number (ESN) is composed of 32 bits, and a manufacturer code (MFC: Manufacturer's Code) is assigned to 8 bits of the most significant bit (MSB) of the 32 bits. The remaining least significant 24-bit bits (LSB) are assigned serial numbers of terminals manufactured by the manufacturer. The manufacturer number is assigned to each manufacturer and uniquely set. On the other hand, if the number of terminals manufactured by the corresponding manufacturer is too large to exceed the serial number (SN) assigned to the corresponding manufacturer, a new manufacturer number (MFC) is allocated.

Meanwhile, as the production of terminals by each manufacturer increases, the electronic serial number (ESN) consisting of 32 bits is expected to be exhausted in the future. Thus, a new identifier for identifying the terminals has been created in place of the electronic serial number (ESN). The new identifier is named Mobile Equipment Identifier (MEID) and is used from IS-2000 Revision D.

5 is a diagram showing the structure of the mobile device identifier (MEID).

As shown in FIG. 5, the mobile device identifier (MEID) consists of a total of 56 bits. The most significant (MSB) 32 bits of the 52 bits are assigned the manufacturer code (MFC), and the least significant (LSB) 24 bits are assigned serial numbers of terminals manufactured by the corresponding manufacturer.

Meanwhile, when the mobile device identifier (MEID) is used instead of the electronic serial number (ESN) as an identifier for identifying the terminal, the public long for the traffic channels using the electronic serial number (ESN). It is required to modify the method for generating a Public Long Code Mask (PLCM).

As described above, when the mobile device identifier (MEID) is used as the identifier for identifying the mobile terminal in the CDMA 2000 system instead of the electronic serial number (ESN), a public long code is used by using the electronic serial number (ESN). It is required to modify the existing method of generating the mask, but a specific method of generating the public long code mask according to the use of the mobile device identifier (MEID) has not been proposed yet.

An object of the present invention is to provide a method for generating a public long code mask using a mobile device identifier (MEID).

According to one aspect of the present invention for achieving the above object, a method for generating a public long code mask in a mobile communication system comprises the steps of: receiving a value of a type (PLCM_TYPE) of the public long code mask through a message, the received public If the type (PLCM_TYPE) of the long code mask is a conventional type, setting the least significant n (n is a positive integer) bits received through the extended channel assignment message (ECAM) to the least significant n bits of a public long code mask, And if the type (PLCM_TYPE) of the received public long code mask is a new type, a mobile device identifier (MEID) consisting of m (m is a positive integer, m> n) bits of the lowest n bits of the public long code mask. And generating the mapping from the.

Preferably, the base station uses an extended channel assignment message (ECAM) as the message, defines a new public long code mask type (PLCM_TYPE) along with the conventional one, and transmits it to the terminal through the extended channel assignment message (ECAM). .

1 is a block diagram illustrating a long code generation method.

2 is a diagram illustrating a long code mask format for a reverse fundamental channel and a reverse auxiliary control channel.

3 shows a long code mask for a reverse fundamental channel, a reverse auxiliary channel, a reverse dedicated control channel, a forward fundamental channel, a forward auxiliary control channel, a forward auxiliary channel, a forward dedicated control channel, and a forward packet data channel. This diagram shows the format.

4 is a diagram showing the structure of the electronic serial number (ESN) consisting of 32 bits.

5 is a diagram showing the structure of the mobile device identifier (MEID).

6 is a diagram illustrating the public long code mask format according to the first embodiment.

7 is a diagram illustrating a public long code mask format according to the second embodiment.

8 is a diagram illustrating a public long code mask format according to the third embodiment.

Hereinafter, when a mobile device identifier (MEID) is used instead of the electronic serial number (ESN) as an identifier for identifying a terminal, a public long code mask is generated for the traffic channels using the mobile device identifier (MEID). Embodiments will be described in detail with reference to the accompanying drawings.

First embodiment

6 illustrates the public long code mask format according to the first embodiment.

According to the first embodiment, to generate a public long code mask for a new traffic channel, the base station defines a new public long code mask type (PLCM_TYPE) in the extended channel assignment message (ECAM) to the mobile device (or terminal). The terminal determines the first least significant 5 LSB bits M36 to M32 of the public long code mask PLCM according to the type (PLCM_TYPE) of the new public long code mask received and received. The second least significant 32 bits M31 to M0 that are lower than the least significant 5 bits are generated by mapping from the mobile device identifier MEID. That is, the terminal generates the second least significant bits M31 to M0 by mapping from the mobile device identifier MEID.

In more detail, the base station sends a conventional value '0001' or a new value '0010' as the type (PLCM_TYPE) of the public long code mask to the terminal through the extended channel assignment message (ECAM). At this time, if the type (PLCM_TYPE) of the public long code mask is a conventional value '0001', the terminal sets the first least significant 5 bits M36 to M32 to '11011', and the first The second least significant bits M31 to M0 that are lower than the least significant (LSB) bits M36 to M32 are the second least significant bits consisting of 32 bits received from the base station through the extended channel assignment message ECAM. Set to the value of (PLCM_32).

On the other hand, if the type of the received public long code mask (PLCM_TYPE) is newly defined '0010', the terminal is the first lowest (LSB) 5 bits (M36 ~ M32) are other traffic channels or other common channel Set to a value that is not used by other channels, including those. In this embodiment, it is set to '10111'. However, if the mobile communication standard is changed so that '10111' is being used as the first least significant 5 bits for other purposes, i. The first least significant 5 bits may be set. In the first embodiment, the above case may be set to '10110' or '00000'. At this time, the principle of determining the first least significant five bits is to determine in descending order starting from the '11111' value.

Meanwhile, the terminal generates the second least significant (LSB) bits M31 to M0 of the public long code mask through mapping from the mobile device identifier MEID consisting of the 56 bits. Further, the terminal generates the second preliminary least significant LS bits of the public long code mask 32 bits N31 to N0 through mapping from the mobile device identifier MEID consisting of the 56 bits. The second preliminary lowest LSB 32 bits N31 to N0 may be permutated to generate the second lowest LSB 32 bits M31 to M0. An example of generating the second lowest order LSB 32 bits M31 to M0 by the permutation is shown in Equations (3) and (4) below.

N31 ~ N0 = {N31, N30, N29,, N2, N1, N0} (3)

M31 to M0 = {N0, N31, N22, N13, N4, N26, N17, N8, N30, N21, N12, N3, N25, N16, N7, N29, N20, N11, N2, N24, N15, N6, N28 , N19, N10, N1, N23, N14, N5, N27, N18, N9} (4)

Second embodiment

7 illustrates a public long code mask format according to the second embodiment.

According to the second embodiment, in order to generate a public long code mask for a new traffic channel, the base station determines the extended channel allocation message (ECAM) according to the first least significant four bits (M35 to M32) of the public long code mask to be used. Define a new public long code mask type (PLCM_TYPE) to the terminal and transmit a second lowest 1 bit (PLCM_M36) higher than the first least significant 4 bits (M35 to M32). And within the Extended Channel Assignment Message (ECAM). The terminal uses the second least significant 1 bit (PLCM_M36) and the new public long code mask type (PLCM_TYPE) received from the base station through the extended channel assignment message (ECAM). M35-M32 and the second least significant (LSB) one bit (M36) are determined.

Meanwhile, the terminal generates the third least significant 32 bits M31 to M0 of the public long code mask by mapping it from the mobile device identifier (MEID) consisting of the 56 bits.

In other words, the base station defines the type (PLCM_TYPE) of the public long code mask according to the first least significant four bits (M35 to M32) to be used in the terminal to the terminal through the extended channel assignment message (ECAM). In addition, the base station should transmit a second least significant bit (PLCM_M36) to the terminal through the extended channel assignment message (ECAM) according to the second least significant one bit (M36) to be used. At this time, the base station selects any one of the values not allocated to the first least significant 4 bits M35 to M32 and the second least significant 1 bit M36 of the other channels or other terminals in the extended channel assignment message (ECAM). Send to the terminal through. The base station transmits a value of the first least significant 4 bits M35 to M32 to the terminal in the type of the public long code mask (PLCM_TYPE) and the second in the form of a new field in the extension code assignment message (ECAM). The value of the least significant 1 bit (PLCM_M36) is transmitted to the terminal.

If the values of the first least significant bits M35 to M32 and the second least significant bit M36 that are not allocated to the other channels or other terminals are '10111', the terminal received by the terminal from the base station The second least significant one bit (PLCM_M36) is '1' and the type (PLCM_TYPE) of the new public long code mask received by the terminal is '0111'.

Meanwhile, if the first least significant bits M35 to M32 and the second least significant one bit M36 that are not already used by the other channels or other terminals do not exist, the terminal is different from the terminals. Minimize collisions with channels while reusing the appropriate values.

However, when the base station sets and transmits the type (PLCM_TYPE) of the public long code mask to the conventional value '0001', the base station does not follow the rules and transmits the first lowest order through the extended channel assignment message (ECAM). The third least significant 32 bits PLCM_32 lower than the bits M35 to M32 are transmitted to the terminal.

In this case, as described above, if the type of the received public long code mask (PLCM_TYPE) is '0001', the terminal includes the second least significant bit M36 and the first least significant bits of the public long code mask. M35 to M32 are set to '11011', and the third least significant 32 bits M31 to M0 are the third least significant 32 bits PLCM_32 received from the base station through the extended channel allocation message ECAM. Set to the value of).

Meanwhile, if the type (PLCM_TYPE) of the public long code mask is not '0001', the terminal receives the second received from the base station through the extended channel allocation message (ECAM) as the second least significant 1 bit (M36) value. A value of the lowest 1 bit (PLCM_M36) is set, and as the first least significant 4 bits (M35 to M32), the type of the public long code mask received from the base station through the extended channel allocation message (ECAM) (PLCM_TYPE). Set to the value of. The third least significant 32 bits M31 to M0, which are lower than the first least significant 4 bits M35 to M32, are generated by mapping from the mobile device identifier MEID consisting of the 56 bits. Alternatively, the terminal generates third preliminary least significant LS bits of the public long code mask 32 bits N31 to N0 through mapping from the mobile device identifier MEID consisting of the 56 bits. The third preliminary lowest LSB 32 bits N31 to N0 may be permutated to generate the third lowest LSB 32 bits M31 to M0. An example of generating the third least significant (LSB) 32 bits M31 to M0 by the permutation is shown in Equations (5) and (6) below. Formula (5) and Formula (6) are the same as Formula (3) and Formula (4), respectively.

N31 ~ N0 = {N31, N30, N29,, N2, N1, N0} (5)

M31 to M0 = {N0, N31, N22, N13, N4, N26, N17, N8, N30, N21, N12, N3, N25, N16, N7, N29, N20, N11, N2, N24, N15, N6, N28 , N19, N10, N1, N23, N14, N5, N27, N18, N9} (6)

Third embodiment

8 is a diagram illustrating a public long code mask format according to a third embodiment.

According to the third embodiment, the base station defines a value of the new public long code mask type (PLCM_TYPE) through the extended channel assignment message (ECAM) and transmits it to the terminal. On the other hand, the terminal is the second least significant 32 bits (M31 ~ M0) lower than the first least significant five bits (M36 ~ M32) and the first least significant five bits (M36 ~ M32) of the public long code mask Generate by mapping each from a mobile device identifier (MEID) consisting of 56 bits.

In more detail, the base station defines a conventional '0001' or a new value '0010' as a value of the public long code mask type (PLCM_TYPE) and transmits it to the terminal through the extended channel assignment message (ECAM). .

Accordingly, when the value of the type (PLCM_TYPE) of the public long code mask received from the base station is conventionally '0001', the terminal sets '11011' as the first least significant bits M36 to M32 of the public long code mask. ', And the second least significant 32 bits M31 to M0, which are lower than the first least significant 5 bits, are the second least significant 32 bits received from the base station through the extended channel assignment message ECAM. PLCM_32).

Meanwhile, if the value of the received public long code mask type (PLCM_TYPE) is '0010' newly defined at the base station, the terminal is configured with the 56 bits of the first least significant bits (M36 to M32). Generate from mapping from mobile device identifier (MEID). In this case, when the terminal selects the values of the first least significant 5 bits (M36 to M32), the terminal selects one of values not used by other channels. The terminal generates through mapping from the second least significant 32 bits (M31 to M0) and the mobile device identifier (MEID) consisting of the 56 bits.

Alternatively, the terminal generates the second preliminary least significant LS bits of the public long code mask 32 bits N31 to N0 through mapping from the mobile device identifier MEID comprised of the 56 bits. The second lowest LSB 32 bits N31 to N0 may be permutated to generate the second lowest LSB 32 bits M31 to M0. An example of generating the second least significant 32 bits M31 to M0 by the permutation is shown in Equations (7) and (8) below. Formula (7) and Formula (8) are the same as that of Formula (5) and Formula (6), respectively.

N31 ~ N0 = {N31, N30, N29,, N2, N1, N0} (7)

M31 to M0 = {N0, N31, N22, N13, N4, N26, N17, N8, N30, N21, N12, N3, N25, N16, N7, N29, N20, N11, N2, N24, N15, N6, N28 , N19, N10, N1, N23, N14, N5, N27, N18, N9} (8)

As described above, according to embodiments of the present invention, when using a mobile device identifier (MEID) instead of an electronic serial number (ESN) as an identifier for identifying terminals, a public long code using the mobile device identifier (MEID) You can create a mask. Accordingly, the public long code mask and the public long code can be generated without the electronic serial number (ESN). In addition, according to embodiments of the present invention, it is possible to generate a public long code mask for new traffic channels while avoiding collision with preset public long code masks.

Those skilled in the art will appreciate that various changes and modifications can be made without departing from the technical spirit of the present invention. Therefore, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification but should be defined by the claims.

Claims (19)

Receiving a value of a type (PLCM_TYPE) of the public long code mask through a message; If the type (PLCM_TYPE) of the received public long code mask is a conventional type, the least significant n (n is a positive integer) bits received through the extended channel assignment message (ECAM) are converted to the least significant n bits of the public long code mask. Setting step; And If the type (PLCM_TYPE) of the received public long code mask is a new type, the least significant n bits of the public long code mask are derived from a mobile device identifier (MEID) consisting of m (m is a positive integer, m> n) bits. And generating a public long code mask in a mobile communication system. The method of claim 1, wherein generating the least significant n bits of the public long code mask comprises: preliminary least significant LSB of the public long code mask via mapping from the mobile device identifier (MEID) of the m bits. generating n bits; And And permuting the preliminary least significant (LSB) n bits to generate the least significant (LSB) n bits. The mobile communication system of claim 1, wherein the type (PLCM_TYPE) of the received conventional public long code mask is '0001', and the type (PLCM_TYPE) of the received new public long code mask is '0010'. How to create a public long code mask in. 2. The method of claim 1, wherein n is 32 and m is 56. 2. The method of claim 1, wherein the message is an Extended Channel Assignment Message (ECAM) from a base station and the mobile communication system is a terminal. Receiving a type (PLCM_TYPE) of a public long code mask through a message from a base station; The first lowest LSB 5 bits M36 to M32 of the public long code mask PLCM are determined according to the type PLCM_TYPE of the received public long code mask, and lower than the first lowest 5 bits. And the second least significant 32 bits (M31 to M0) have a step of mapping from the mobile device identifier (MEID) to generate the public long code mask. The method according to claim 6, wherein if the type (PLCM_TYPE) of the received public long code mask is a conventional value '0001', the first least significant 5 LSB bits M36 to M32 are set to '11011', and The second least significant bits M31 to M0 lower than the first least significant (LSB) bits M36 to M32 are second least significant bits PLCM_32 composed of 32 bits received from the base station through the message. And setting a value to a value of. A method of generating a public long code mask in a mobile communication system. 7. The method of claim 6, wherein if the type (PLCM_TYPE) of the received public long code mask is newly defined '0010', the first least significant (LSB) 5 bits (M36-M32) are delimited by other channels. Setting a fixed value to an unused value; The second least significant (LSB) bits M31 to M0 of the public long code mask are generated through mapping from the mobile device identifier (MEID) consisting of the 56 bits or consist of the 56 bits. After generating the second preliminary least significant (LSB) 32 bits (N31 to N0) of the public long code mask through mapping from the mobile device identifier (MEID), the second preliminary least significant (LSB) 32 bits (N31) Permuting ˜N0) to generate the second least significant (LSB) 32 bits (M31 ˜M0). The method of claim 8, wherein the second preliminary least significant (LSB) 32 bits (N31 to NO) and the second least significant (LSB) 32 bits (M31 to M0) are: N31-N0 = {N31, N30, N29,, N2, N1, N0}, M31 to M0 = {N0, N31, N22, N13, N4, N26, N17, N8, N30, N21, N12, N3, N25, N16, N7, N29, N20, N11, N2, N24, N15, N6, N28 N19, N10, N1, N23, N14, N5, N27, N18, N9}. Define a type (PLCM_TYPE) of the public long code mask through a message according to the first least significant four bits (M35 to M32) of the public long code mask to be used in the base station, and the first least significant four bits (M35 to M32) Creating a higher second least significant one bit (PLCM_M36) in the message in the form of a new field and transmitting them to the terminal; The first least significant four bits (M35 to M32) and the second using the second least significant one bit (PLCM_M36) and the new public long code mask type (PLCM_TYPE) received through the message from the base station in the terminal. Determining a second least significant LSB one bit M36; And The third lower 32 bits M31 to M0 of the public long code mask in the terminal are generated by mapping from a mobile device identifier (MEID) composed of 56 bits. How to create a long code mask. 12. The method of claim 10, wherein when the type (PLCM_TYPE) of the received public long code mask is a conventional value '0001', the terminal indicates that the second least significant bit (M36) of the public long code mask is '1' and the The first least significant bits M35 to M32 are set to '1011', and the third least significant 32 bits M31 to M0 are the third least significant 32 bits PLCM_32 received from the base station through the message. A method of generating a public long code mask in a mobile communication system, characterized in that the set to the value of. If the type (PLCM_TYPE) of the public long code mask is not '0001', the terminal is the second least significant one bit (M36) value of the second least significant one bit (PLCM_M36) received from the base station through the message. Set to a value, and set as the first least significant 4 bits M35 to M32 to the value of the type of the public long code mask (PLCM_TYPE) received from the base station through the message, and the first least significant 4 bits. And the third least significant 32 bits (M31 to M0), which are lower than M35 to M32, are generated by mapping from a mobile device identifier (MEID) consisting of the 56 bits. How to create a public long code mask on your system. 13. The method of claim 12, wherein generating the third least significant 32 bits (M31-M0) comprises: mapping from the mobile device identifier (MEID) of the 56 bits via mapping of the public long code mask. After generating the third preliminary least significant (LSB) 32 bits (N31 to N0), the third preliminary least significant (LSB) 32 bits (N31 to N0) are permutated to generate the third least significant (LSB) 32 bits. And generating (M31 to M0) the public long code mask in the mobile communication system. Receiving a type (PLCM_TYPE) of a public long code mask through a message; And Shift consisting of 56 bits of the first least significant 5 bits (M36 to M32) and the second least significant 32 bits (M31 to M0) that are lower than the first least significant 5 bits (M36 to M32) of the public long code mask. And mapping each device from a device identifier (MEID) to generate a public long code mask. 15. The method of claim 14, wherein if the value of the received type of the public long code mask (PLCM_TYPE) is a conventional '0001', '11011' as the first least significant bits (M36 to M32) of the public long code mask. And setting the second least significant 32 bits M31 to M0 lower than the first least significant 5 bits to a value of the second least significant 32 bits PLCM_32 received through the message. A method of generating a public long code mask in a mobile communication system, characterized in that the. The mobile device of claim 14, wherein the value of the first least significant bits (M36 to M32) is composed of the 56 bits when the value of the received public long code mask (PLCM_TYPE) is newly defined '0010'. Generating through mapping from an identifier MEID; And Generating a public long code mask in the mobile communication system, wherein the second lowest 32 bits M31 to M0 are generated by mapping from the mobile device identifier (MEID) including the 56 bits. How to. 17. The public long code of claim 16, wherein when the value of the first least significant 5 bits (M36 to M32) is selected, one of values not used by other channels is selected. How to create a mask. 17. The method of claim 16, wherein generating the second least significant 32 bits (M31-M0) is performed by mapping from the mobile device identifier (MEID) of the 56 bits to a second preliminary least significant of the public long code mask. (LSB) After generating 32 bits (N31 to N0), the second preliminary least significant (LSB) 32 bits (N31 to N0) are permutated so that the second least significant (LSB) 32 bits (M31 to M0). Generating a public long code mask in a mobile communication system. 19. The method of claim 18, wherein the second preliminary least significant (LSB) 32 bits (N31 to NO) and the second least significant (LSB) 32 bits (M31 to M0), respectively, N31 to N0 = {N31, N30, N29,, N2, N1, N0}, M31 to M0 = {N0, N31, N22, N13, N4, N26, N17, N8, N30, N21, N12, N3, N25, N16, N7, N29, N20, N11, N2, N24, N15, N6, N28 N19, N10, N1, N23, N14, N5, N27, N18, N9}.