A new approach to long code acquisition in spread spectrum radio

The authors present a novel algorithm for very long pseudonoise (PN) code acquisition in spread-spectrum radio, the so-called three-level acquisition scheme. In the first step (level) only a short PN code (preamble) is transmitted for a short time (T/sub 1/), during which the receiver is supposed to acquire its synchronization. In the next step, during T/sub 2/, a binary signal, representing the initial state of the long PN code, is combined with the short PN code and transmitted to the receiver. For a successful long code acquisition the receiver is supposed to acquire synchronization of the short PN code during the time interval T/sub 1/ and to correctly detect the initial state of the long PN code generator during the time interval T/sub 2/. In the third step, the synchronization is checked during the interval T/sub 3/.