Radio transmission method and apparatus for digital information

摘要

A baseband digital IQ signal modulated by digital information and a spread spectrum IQ code sequence whose auto-correlation side lobe is equal to zero are frame-synthesized with each other to obtain a transmission baseband IQ signal. A modulated radio-frequency wave obtained by modulating a radio-frequency wave is transmitted over a radio transmission line. From a received baseband signal obtained by receiving the modulated radio-frequency wave is separated a received signal of the spread spectrum IQ code sequence and a received signal of the baseband digital-modulated IQ signal. A waveform equalized signal which is obtained by waveform-equalization of the received signal of the baseband digital modulated IQ signal is demodulated by the use of transmission parameters of the radio transmission line derived from a despread spectrum signal obtained by dispreading the spread spectrum IQ code sequence, to obtain a received data signal of the digital information transmitted from the transmitting side.