Patent ID: 6160838
Filing Date: 2000-12-12
Classification: H04B

Abstract:
A method of spread spectrum communication using QPSK modulation system, comprising:a delay step for applying, to one of the IQ (in-phase, quadrature phase) components, a time difference Td with respect to the other component (Tc<Td<T/2, where Tc is the spreading code chip period, and T is the symbol period);a modulation step for modulating the I component with a carrier signal and the Q component with a carrier signal to which is applied a prescribed phase difference;a transmission step for synthesising and transmitting the modulated IQ components;a reception step for receiving the transmitted signal;a demodulating step for demodulating the received signal with said carrier signal and carrier signal to which said prescribed phase difference has been applied into respective IQ components; anda decoding step for decoding the data using vector of the received signal at time point t and vector of the received signal at time point (t+Td).