Abstract: A current mode of operation is provided to a Walsh spreader (203), and based on the current mode of operation, the Walsh spreader (203) either varies a Walsh code at a symbol rate, or holds the Walsh code constant. During multi-carrier transmission a first symbol within a data stream (210) is spread with a first Walsh code, while symbols immediately preceding and following the first symbol are spread by a another, differing Walsh code. The sequence of Walsh codes exiting the spreader (201) is further scrambled by a pair of Pseudo-Noise (PN) codes (224) that are held constant for three Walsh code periods during multi-carrier transmission, and are not held constant during direct-spread transmission.
Type:
Grant
Filed:
November 24, 1998
Date of Patent:
July 18, 2000
Assignee:
Motorola, Inc.
Inventors:
Ron Rotstein, Yuda Yehuda Luz, Robert John Corke