Patent ID: 7609206

Claim:
A method for enabling digital beamforming (DBF) techniques within a system having a multi-element array antenna receiving RF signals in a noise environment, said RF signals having short repetitive synchronization sequences, said method of enabling DBF techniques, comprising the steps of: a) receiving repetitive synchronization RF signals utilizing a multi-element array antenna, each of said repetitive synchronization RF signals comprising an ideal known synchronization sequence, said ideal known synchronization sequence being denoted as y d and a length of said ideal known synchronization sequence being denoted as N d ; b) calculating a sequence of magnitudes and phases for each element of said multi-element array antenna corresponding to each of said ideal known synchronization sequences in said received synchronization RF signals, said sequence of said magnitudes and said phases comprising an array of N elements and being denoted as x, wherein said phases are also referred to as absolute phases; c) calculating a relative phase for each element in said sequence of said magnitudes and said absolute phases by referencing said absolute phases of all elements in said array x of N elements to a phase of a single element in said array x of N elements; d) converting said array x of N elements with said magnitudes and said absolute phases into an array of N elements with said magnitudes and said relative phases by replacing each of said absolute phases in said array x of N elements with said calculated relative phase for each element, said array of N elements with said magnitudes and said relative phases being denoted as x r ; e) calculating a relative cross correlation vector for each element of said multi-element array antenna utilizing said x r and said y d , said relative cross correlation vector being denoted as r xd , where r xd =E{x r y d *} and * is a complex conjugate; and, f) generating a relative cross correlation vector estimate by filtering said r xd , for use with DBF techniques.