| 摘要 |
PURPOSE:To suppress demodulation error at a minimum even when plural narrow band jamming signals are existent at the spread spectrum(SS) communication equipment. CONSTITUTION:At a transmitter T, a first PN code (A) from a PN code generator 1 and a second PN code (B) of a delayed phase from a shift register 3 are inputted to a multiplexer (MPX) 2 and switched by an exclusive OR output between data (c) from an EOR 17 and a disturbance signal (D), and a high frequency signal is modulated by a modulator 4 and transmitted. At a receiver R, a correlative output (E) is detected by a detection circuit 12, the detected output is binarized by a voltage comparator 13, and an obtained correlative pulse (F) is impressed to AND gates 14 and 15. Time window pulses (G) and (H) are added to MPX 18 and 19, switched by a control signal (I) and impressed to the AND gates 14 and 15. The pulses from the AND gates 14 and 15 are counted by the up-down counter of a demodulation circuit 16 and data are demodulated. |
