초록 ▼

A code division multiple access (CDMA) mobile communication system with improvements to permit stable reception with a minimum of bit error. The system comprises a voltage-controlled oscillator for supplying a carrier to a radio frequency quadrature demodulator, and a frequency controller for detect

A code division multiple access (CDMA) mobile communication system with improvements to permit stable reception with a minimum of bit error. The system comprises a voltage-controlled oscillator for supplying a carrier to a radio frequency quadrature demodulator, and a frequency controller for detecting a frequency error from a phase correction signal of the first step to generate a control signal that controls the oscillator. The frequency controller includes an extracting circuit and an integrating circuit. The extracting circuit extracts a phase change based on the frequency error derived from the phase correction signal of the first step and from a signal preceding that signal by a predetermined delay time. The integrating circuit integrates the phase change and outputs the integrated result as the control signal. The predetermined delay time is preferably set within a range not exceeding the delay time needed for averaging by an averaging circuit that receives the phase correction signal of the first step and outputs a phase correction signal. The carrier to a radio frequency quadrature modulator is preferably supplied from the voltage-controlled oscillator.

대표청구항 ▼

[ What is claimed is:] [1.] A code division multiple access mobile communication system for spreading, modulating and transmitting a pilot signal along with data into radio frequency band signals, demodulating and despreading the received radio frequency band signals into a received pilot signal and

[ What is claimed is:] [1.] A code division multiple access mobile communication system for spreading, modulating and transmitting a pilot signal along with data into radio frequency band signals, demodulating and despreading the received radio frequency band signals into a received pilot signal and received data, and generating a phase correction signal from the received pilot signal so that a phase error of the received data is corrected by use of said phase correction signal during detection, the system comprising:a plurality of mobile stations and a base station, said base station establishing up and down links in conjunction with said plurality of mobile stations;each of said plurality of mobile stations having a detection circuit including:a voltage-controlled oscillator for supplying a carrier to a radio frequency quadrature demodulator demodulating the received radio frequency band signals;an averaging circuit for averaging a first step phase correction signal generated from the received pilot signal and outputting said phase correction signal; anda frequency controller for detecting a frequency error from said first step phase correction signal, said frequency controller further generating from said frequency error a control signal to control the frequency of the carrier generated by said voltage-controlled oscillator, wherein said frequency controller comprises:a phase change generating circuit for generating a phase change based on said frequency error derived from said first step phase correction signal and a signal preceding said first step phase correction signal by a predetermined delay time; andan integrating circuit for integrating said phase change and outputting the integrated result as said control signal.