METHODS AND APPARATUS FOR PROVIDING ROBUST SYNCHRONIZATION OF RADIO TRANSCEIVERS

METHOD 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 STRT 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 MORTE SUBSTANTIALLY DC-FREE TRAILING PARTS FOLOW THE SYNCHRONIZATION PART, OR ARE INCLUDED IN THE SYNCHRONIZATION PART ITSELF, AND PROVIDE FOR FINE OF THE DC-OFFSET ESTIMATE. SINCE TH 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.FIG. 2