A SFH spread spectrum synchronization algorithm for data broadcasting

In this paper, a practical slow frequency hopping (SFH) spread spectrum discrete synchronization algorithm suitable for data broadcasting is proposed. This algorithm uses additional sync bits in the binary stream of the slow frequency hopping signals for both initial synchronization and tracking purposes. A complete hop period or a complete rime slot in every frame is used to carry these additional sync bits. These sync bits are changed at each frame and are used to control the startup condition of the pseudo-random number (PN) generator. As a result, a robust algorithm with fast synchronization rime is obtained. The security measure is enhanced while at the same rime using simpler hardware, requiring only one detector. It can also be used in systems with any number of hop channels, whether large or small, and may operate with several broadcasters simultaneously in a cell to improve the spectra usage.