NETZZUGANGSKANAL FÜR CDMA-SYSTEME

An OCDMA satellite communication system in which an earth-based hub station receives, via a satellite, a plurality of spread spectrum signals from a corresponding plurality of earth-based subscriber stations on a selected frequency channel, each signal from a subscriber station being composed of data symbols overlaid with one set of orthogonal Rademacher-Walsh (RW) functions and a pseudo-noise PN sequence, the signals from subscriber stations being synchronized to arrive at the hub station in time and frequency synchronism. A subscriber station net entry channel (NEC) is comprised of a transmitter function at the subscriber stations for transmitting a spread spectrum NEC signal located in a spectral null of the OCDMA signals between the earth-based hub station and the subscriber stations. Receiver functions at the earth-based hub station detect and demodulate the NEC signal and assign a frequency and RW function to the user, and transmits frequency and time correction signals to the user to assure that the user is near time synchronism upon net entry.