| 摘要 |
Methods and apparatus for performing synchronization and DC-offset compensation in FM transmission systems significantly reduce the overhead associated with transmitting a conventional digital preamble at the start of each of a succession of transmitted digital data packets. According to exemplary embodiments, a multi-part digital preamble includes a short, substantially DC-free leading part followed by a code-protected synchronization part which is not necessarily substantially DC-free. The leading part provides for coarse DC offset estimation and synchronization, while the coded synchronization part carries timing and/or other useful information which can be unique for each packet. One or more substantially DC-free trailing parts follow the synchronization part, or are included in the synchronization part itself, and provide for fine tuning of the DC-offset estimate. Since the substantially DC-free leading and trailing parts are extremely short, and since the synchronization part carries useful information, the overhead associated with a preamble according to the invention is significantly reduced as compared to a conventional, entirely DC-free, preamble. |
