| 摘要 |
PURPOSE:To surely and quickly obtain synchronization at code hopping by outgoing a level transition pulse train corresponding to the code prior to the start of code modulation by pseudo noise as a pilot signal. CONSTITUTION:At least one shoed noises selected among plural pseudo noise generators 102 and used as a code modulation for an input signal as a spread code at the transmission and the reference code is used to demodulate a reception signal by the synchronization of the reference code of an S unit 18 corresponding individually to the selected noise. In selecting the pseudo noise, prior to the start of code modulation by the normal noise to be selected, a code transition pulse train corresponding to the code is originated as a pilot signal. That is, prior to the code hopping, the pilot signal is transmitted in advance to the receiver side to take tentative synchronization and the code change is executed while confirming it. Thus, the synchronizing time is shortened surely. |
