DEVICE AND METHOD FOR GENERATING SPREAD SPECTRUM SIGNAL USING PSEUDO-ORTHOGONAL CODE IN CDMA MOBILE COMMUNICATIONS SYSTEM

摘要

[A spread spectrum signal generating device using a pseudo-orthogonal code in a CDMA mobile communications system. In the device, a signal converter converts an input channel data bit stream, a pseudo-orthogonal cod e generator generates a pseudo-orthogonal code being a combination of M different Walsh codes, a PN code generator generates a PN code being a real part and a PN code being an imaginary part, a pseudo-orthogonal code spreading and PN code portion divides the converted signal into M signal sequences, multiplies each signal sequence by the pseudo-orthogonal code, generates MxN signal sequences, and multiplies each spread signal sequence by a PN code for PN masking, and an output portion baseband-pass-filters the output of the pseudo-orthogonal code spreading and PN masking portion and shifts the frequency of the filtered signal to an RF frequency.] A pseudo-orthogonal code generating method for use in orthogonally spreading channel data in a CDMA mobile communications system. In the method, M orthogonal codes are selected from N orthogonal codes. for forming a pseudo-orthogonal code. and the elements of the selected M orthogonal codes are sequentially interlaced, to thereby generate the pseudo-orthogonal code as a sequence of MxN elements.