| 摘要 |
PURPOSE:To improve the privateness by providing two PN signal generators synchronizing with a frame synchronizing signal and using one of them for the scrambling of a signal itself and using the other for generation of a frequency hopping pattern. CONSTITUTION:In the modulator of a spectrum spread communication system, a polynomial circuit 39 constitutes the PN generating circuit used for the scrambling of the signal itself, and a PN generating circuit 40 is used for the generation of a frequency hopping pattern. The PN of a 7th-degree polynomial synchronizing with bits and frames is generated by the PN generating circuit 40. A subframe where 128 bits of this PN is one cycle is repeated 8 times in one frame of 1,024 bits. A frequency hopping signal consisting of the first 16 bits of the frame is a sweep pattern signal for acquisition and is offered from a frame synchronization control part 38. The PN frequency hopping pattern signal and the sweep pattern signal for acquisition are sent to a D/A converter 43. |
