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-orthogonalcode in a CDMA mobile communications system. In the device, a signalconverter converts an input channel data bit stream, a pseudo-orthogonal codegenerator generates a pseudo-orthogonal code being a combination of Mdifferent Walsh codes, a PN code generator generates a PN code being a realpart and a PN code being an imaginary part, a pseudo-orthogonal codespreading and PN code portion divides the converted signal into M signalsequences, multiplies each signal sequence by the pseudo-orthogonal code,generates MxN signal sequences, and multiplies each spread signal sequenceby a PN code for PN masking, and an output portion baseband-pass-filters theoutput of the pseudo-orthogonal code spreading and PN masking portion andshifts the frequency of the filtered signal to an RF frequency.]A pseudo-orthogonal code generating method for use in orthogonallyspreading channel data in a CDMA mobile communications system. In themethod, M orthogonal codes are selected from N orthogonal codes. forforming a pseudo-orthogonal code. and the elements of the selected Morthogonal codes are sequentially interlaced, to thereby generate thepseudo-orthogonal code as a sequence of MxN elements.