SPREAD SPECTRUM SIGNAL GENERATING DEVICE AND METHOD IN TRANSMITTER OF MOBILE COMMUNICATIONS SYSTEM

摘要

There are provided spread spectrum signal generating device and method in a transmitter of a mobile communications system using a plurality of logic chann els. In the spread spectrum signal generating device, a multiplexer tune multiplexes a pilot channel signal and a control channel signal which are output at constant p ower levels, a first orthogonal encoder orthogonally spreads the output of the multip lexer with an orthogonal code, a second orthogonal encoder orthogonally spreads voice channel data of a variable bit rate with an orthogonal code, a third orthogonal encoder orthogonally spreads packet channel data of a variable bit rate with an orthogonal code, an IQ signal mapper adds the outputs of the first and third orthogonal encoders, outputs the added signal as a first channel signal, and out puts the output of the second orthogonal encoder as a second channel signal, and a PN spreader spreads the first and second channel signals with PN codes and outputs a final spectrum spread signal. Therefore, a peak-to-average power ratio of the transmitter is maintained to be uniform.