SPREADING CODE GENERATOR AND CDMA COMMUNICATION SYSTEM

摘要

A spreading code generator generates a spreading code by modulo-two addition of two internal spreading codes. The first internal spreading code is part of a pseudorandom noise sequence, created by resetting a pseudorandom noise generator to an assigned initial state at intervals determined by counting a framing signal. The second spreading code is selected from a set of preferably orthogonal sequences, the selected sequence being repeated at intervals shorter than the period of the framing signal. A code-division multiple-access communication system employs this spreading code generator to generate all spreading codes used at all communicating stations. One of the spreading codes generated at each station is transmitted as a synchronization signal.