Device and method for generating quaternary complex quasi-orthogonal code and spreading transmission signal using quasi-orthogonal code in CDMA communication system

A channel transmission device for a code division multiple access (CDMA) communication system, comprising:

• a generator including a quaternary complex quasi-orthogonal code mask, for generating a quaternary complex quasi-orthogonal code by applying the quaternary complex quasi-orthogonal code mask to a Walsh code wherein the quaternary quasi-orthogonal code mask is featured in that a correlation value for respective parts of a length N/M, where N is the whole length of said quaternary complex quasi-orthogonal code and another quaternary complex quasi-orthogonal code, does not exceed N M ,
• where M=2m, m=0,1, . . . ,log2N;
• a channel spreader for generating a channel spread signal by operating on the converted complex signal and the quaternary complex quasi-orthogonal code;
• and
• a PN (Pseudo Noise) masking part for generating a PN masked channel signal by operating on the channel spread complex signal and complex PN sequences.

A quaternary complex quasi-orthogonal code generation device for a channel transmission device in a code division multiple access (CDMA) communication system, which spreads a channel signal using a quaternary complex quasi-orthogonal code, comprising:

• a first generator for generating a quaternary quasi-orthogonal code mask corresponding to a designated code index wherein the quaternary quasi-orthogonal code mask is featured in that a correlation value for respective parts of a length N/M, where N is the whole length of said quaternary complex quasi-orthogonal code and another quaternary complex quasi-orthogonal code, does not exceed N M ,
• where M=2m, m=0,1, . . . ,log2N;
• a second generator for generating a Walsh orthogonal code corresponding to a designated Walsh orthogonal code index;
• and
• an adder for generating a quaternary quasi-orthogonal code by operating the quaternary quasi-orthogonal code mask and the Walsh orthogonal code.

A quaternary complex quasi-orthogonal code generation device for a channel transmission device in a code division multiple access (CDMA) communication system, which spreads a channel signal using a quaternary complex quasi-orthogonal code, comprising:

• a first generator for generating I- and Q-component quaternary quasi-orthogonal code masks corresponding to a designated code index wherein the quaternary quasi-orthogonal code mask is featured in that a correlation value for respective parts of a length N/M, where N is the whole length of said quaternary complex quasi-orthogonal code and another quaternary complex quasi-orthogonal code, does not exceed N M ,
• where M=2m, m=0,1, . . . ,log2N;
• a second generator for generating a Walsh orthogonal code corresponding to a designated Walsh orthogonal code index;
• and
• an adder for generating I- and Q-component quaternary quasi-orthogonal codes by adding the I- and Q-component quaternary quasi-orthogonal code masks and the Walsh orthogonal code.

A channel transmission method for a code division multiple access (CDMA) communication system, comprising the steps of:

• generating a quaternary quasi-orthogonal code mask corresponding to a designated code index, and generating a quaternary complex quasi-orthogonal code by using the generated quasi-orthogonal code mask and the Walsh orthogonal code wherein the quaternary quasi-orthogonal code mask is featured in that a correlation value for respective parts of a length N/M, where N is the whole length of said quaternary complex quasi-orthogonal code and another quaternary complex quasi-orthogonal code, does not exceed N M ,
• where M=2m, m=0,1, . . . ,log2N;
• generating a channel spread signal by using the converted complex signals and the quaternary complex quasi-orthogonal codes;
• and
• generating PN masked channel signals by using the channel spread complex signals and complex PN sequences.

A quaternary complex quasi-orthogonal code generation method for a channel transmission device in a code division multiple access (CDMA) communication system, which spreads a channel signal using a quaternary complex quasi-orthogonal code, comprising the steps of:

• generating a quaternary quasi-orthogonal code mask corresponding to a designated code index wherein the quaternary quasi-orthogonal code mask is featured in that a correlation value for respective parts of a length N/M, where N is the whole length of said quaternary complex quasi-orthogonal code and another quaternary complex quasi-orthogonal code, does not exceed N M ,
• where M=2m, m=0,1, . . . ,log2N;
• generating a Walsh code corresponding to a designated Walsh orthogonal code index;
• and
• generating a quaternary quasi-orthogonal code by using the quaternary quasi-orthogonal code mask and the Walsh orthogonal code.

A quaternary complex quasi-orthogonal code generation method for a channel transmission device in a code division multiple access (CDMA) communication system, which spreads a channel signal using a quaternary complex quasi-orthogonal code, comprising the steps of:

• generating I- and Q-component quaternary quasi-orthogonal code masks corresponding to a designated code index wherein the quaternary quasi-orthogonal code mask is featured in that a correlation value for respective parts of a length N/M, where N is the whole length of said quaternary complex quasi-orthogonal code and another quaternary complex quasi-orthogonal code, does not exceed N M ,
• where M=2m, m=0,1, . . . ,log2N;
• generating a Walsh code corresponding to a designated Walsh orthogonal code index;
• and
• generating I- and Q-component quaternary quasi-orthogonal codes by using the I- and Q-component quaternary quasi-orthogonal code masks and the Walsh orthogonal code.