NON-RECURSIVELY GENERATED ORTHOGONAL PN CODES FOR VARIABLE RATE CDMA

摘要

A method and apparatus for constructing a series of PN code sets (30) that can be used for multirate synchronous and quasi-synchronous CDMA systems. The construction technique produces PN codes (22) that are balanced, and that furthermore do not require any synchronization of neighboring base stations. The method is a non-recursive method that uses a permuted orthogonal matrix (24) to modulate permuted orthogonal matrices to create PN codes that support multirate operation. Furthermore, the codes constructed using the method have very good spectral properties (if chosen properly) when the code length, n, is reasonably large.