| 摘要 |
PROBLEM TO BE SOLVED: To provide a method and system for conducting multi-user communication in a satellite network on a CDMA basis. SOLUTION: A satellite receiver receives a signal including a user message that is subjected to differential phase coding at a differential encoder 12, spread by using the Walsh function and a pseudo-random number(PN) sequence and coded. the received signal is quadrature-demodulated in a non-coherent way and de-spread by using the PN sequence and the Walsh function. A differential phase signal is recovered on a satellite, and the result is switched to a selected outgoing link transmitter. The quadrature component of the signal is spread again by using the Walsh function and the PN sequence. The quadrature modulation is applied to the signal, and the result is sent to a ground receiver. The received signal is quadrature-demodulated coherently, and then the user message subject to de-spreading and coding is detected and decoded by using the Walsh function and the PN sequence succeedingly. |
