Patent ID: 7522689

Claim:
A method of aligning a frame clock of a slave device to a clock of a master device in a frequency hopping mobile communication system, comprising: receiving an access code and a packet header from the master device on a preselected scanning frequency corresponding to a preselected clock value of the slave device, wherein the preselected scanning frequency is determined by a hop selection mechanism using the preselected clock value; determining whether the access code is correlated; when the access code is correlated, attempting to decode the packet header using a scrambling sequence based on the preselected clock value; when the decoding is unsuccessful, attempting to decode the packet header using one or more additional scrambling sequences, the additional scrambling sequences based on different clock values near the preselected clock value, wherein the different clock values point to the same hop frequency as the preselected clock value but to a different scrambling sequence; determining for each decoding attempt, whether the packet header was decoded correctly; and aligning the frame clock of the slave device using a clock value associated with the scrambling sequence that resulted in correct decoding of the packet header.