METHOD AND APPARATUS FOR ESTIMATING CARRIER FREQUENCY OFFSET AND FADING RATE USING AUTOREGRESSIVE CHANNEL MODELING

摘要

A METHOD FOR USE BY A RECEIVER OF A WIRELESS COMMUNICATION SYSTEM IN PROVIDING INFORMATION OF USE IN ADAPTING TO CHANGING CHARACTERISTICS OF A COMMUNICATION CHANNEL (22) OVER WHICH THE RECEIVER (23) RECEIVES A SIGNAL AT AN OFFSET FROM A CARRIER FREQUENCY DUE TO CHANGES IN THE CHARACTERISTICS OF THE COMMUNICATION CHANNEL CHARACTERISTICS, THE CHANGING COMMUNICATION CHANNEL CHARACTERISTICS ALSO CAUSING FROM TIME TO TIME CHANGES IN OTHER CHARACTERISTICS OF THE COMMUNICATION CHANNEL (22), THE METHOD CHARACTERIZED BY: A STEP (23B-1A 23B-1B) OF PROVIDING EXPECTATION MAXIMIZATION ESTIMATES OF AUTOREGRESSIVE PARAMETERS REPRESENTING THE CHANGING COMMUNICATION CHANNEL (22) USING RECEIVED SIGNAL SAMPLES EXTRACTED FROM THE RECEIVED SIGNAL AND CORRESPONDING TO TRANSMITTED PILOT SYMBOL; AND A STEP (23B-1A 23B-1C) OF PROVIDING AN ESTIMATE OF THE CHANNEL IMPULSE RESPONSE AND AN ESTIMATE OF A FREQUENCY OFFSET OF AT LEAST ONE MULTIPATH SIGNAL BASED ON THE ESTIMATED VALUES OF THE AUTOREGRESSIVE PARAMETERS. FIG.2&3