| 摘要 |
<p>PURPOSE:To minimize the time required until data demodulation after channel disconnection and reconnection in a spectrum spread communication system using direct spreading. CONSTITUTION:One of two waves, a signal modulated only by a spreading code or the signal modulated by the spreading code and data, is delayed by a delay element 115, synthesized by a wave synthesizer 116 and transmitted from an antenna 119. It is divided into halves by a receiver and a distributer 132, one remains as it is, the other is delayed by the delay element 145 and they are inputted to a correlator 167 or 170 by the base band components of I and Q. Then, the respective pieces of output are multiplied by multipliers 171 and 172, the respective pieces of multiplied output are added by an adder 173 and thus, the data are demodulated. Thus, a user is discriminated by codes and delay time, the delay time is varied and the waves are synthesized.</p> |
