| 摘要 |
PROBLEM TO BE SOLVED: To provide the communication equipment that conducts transmission reception by the hierarchical transmission system in the spread spectrum communication adopting delay multiplex. SOLUTION: Transmission data are given to a hierarchical circuit 1, where a data string m1 is converted into two stages of layers with higher importance than m2, each data string is differential coded at differential coding circuits 2, 3, where I1, Q1 and I2, Q2 having provision for QPSK are generated. The data are spread by spread sections 5-8 by using the Barker code from a spread code generating circuit 4, data obtained spreading the string m2 are given to delay sections 9, 10, where a delay by 3 tips is given. Data at the same time are multiplexed by multiplexer.sections 11, 12, the multiplexed data are modulated by guadrature modulation section 13, the frequency is converted into a prescribed frequency at a frequency converter 14 and the converted frequency signal is sent from an antenna 15. In the case of a delay by 3 tips, the string m1 has 8 chips and the string m2 has 3 tips in the delay interval from a preceding multiplexed wave, and then the string m1 is more stably demodulated. |
