QUADRATURE SPREAD SPECTRUM COMMUNICATION SYSTEM AND CODE DIVISION MULTIPLE ACCESS SYSTEM

摘要

PURPOSE: To improve the transmission characteristic by using a correlation processing means with gate between a spread demodulation code and a signal in a spread code length block after the synchronization between a reception signal and a spread demodulation code is established in spread demodulation processing. and to reduce interference between spread spectrum signals. CONSTITUTION: A guard block code addition section 10 at a transmitter side adds a code of a guard time block to a modified M sequence to generate a spread spectral code. Then input information bit 1 is modulated by an information modulation section 2 and subject to spread spectrum processing at a spread spectrum modulation section 3 based on the spread code to be a spread spectrum signal 4. Furthermore, a spread spectrum code generating section 17 at a receiver side generates a spread spectrum signal for spread spectrum demodulation and a spread spectrum demodulation section 15 applies gated correlation processing to the signal and a received spread spectrum signal 14 by a spread spectrum demodulation section 15 to attain spread spectrum modulation without interference. Then an information demodulation section 16 demodulates the information to provide an output of output bit information 22.