Patent ID: 6498789
Filing Date: 2002-12-24
Classification: H04B,H04J

Abstract:
A CDMA mobile communications device comprising:a transmission section including: a transmission data preparation section, an encoding section for detecting and correcting an error, a long cycle string code (long code) generator used for primary spreading operations, a long code modulator which processes the long code and an output from the encoding section by means of an exclusive OR operation; a short code spreader which divides an output from the long code modulator into in-phase components and quadrature components and processes the components by means of secondary spread through use of a short cycle string code (short code), a frequency conversion section which converts the frequency of an output from the short code spreader into a radio frequency range, an amplifier for amplifying the thus-frequency-converted signal, and an antenna; and a receiving section including: a radio receiving section for converting a signal received by an antenna into a signal of base band range, a RAKE receiving section which separates an output from the radio receiving section for each transmission path and despreads the thus-separated outputs for each in-phase component and for each quadrature component by means of despreading operations through use of the short code, a symbol combining section which combines outputs from the RAKE receiving section, a buffer which decimates the output from the long code generator of the transmission section and stores the thus-removed long codes, a buffer control section which controls read and write addresses of the buffer, a long code demodulator which processes the long code (received long code) output from the buffer and the received signal (received symbol) output from the symbol combining section by means of exclusive OR operations, a reference clock signal generator for producing a clock signal which runs at the cycle of the received symbol, an error detection-and-correction section which reproduces received data by detection and correction of an error in the symbol output from the long code demodulator, and a demodulated data processing section which decomposes the reproduced data into a sound signal and a control signal.