Patent ID: 6023477
Filing Date: 2000-02-08
Classification: H04B,H04L,H04W

Abstract:
In a receiver, a method of obtaining time synchronization with a predetermined portion of a signal broadcast by a transmitter, the predetermined portion being broadcast at predetermined repetition intervals, wherein the receiver determines the repetition intervals with errors, comprising the steps of:sampling the signal and storing samples at respective locations in a memory, wherein the memory locations are identified by respective addresses;selecting a postulate of addresses of memory locations in which samples corresponding to a first occurrence of the predetermined portion are likely to have been stored;determining a succession of measurement values related to the predetermined portion from the samples stored in the memory locations identified by the postulate of addresses, wherein a first measurement value is determined from samples that begin at a starting address and the successive measurement values are determined by incrementing the starting address until all samples stored at the postulate of addresses have been used;storing the succession of measurement values in memory locations having sequential addresses;additively combining a selected one of measurement values stored in memory locations having a first group of sequential addresses with measurement values stored in memory locations having a second group of addresses, wherein the first group of addresses corresponds to measurement values determined from a first likely occurrence of the predetermined portion and the second group of addresses corresponds to measurement values determined from a subsequent likely occurrence of the predetermined portion, and the addresses in the first group are separated from the addresses in the second group by amounts corresponding to the repetition interval and in a range from the repetition interval less an uncertainty in the interval to the repetition interval plus the uncertainty in the interval; anddetermining an optimal one of the combined values, thereby obtaining time synchronization with the predetermined portion.