Abstract: In a spread spectrum multipoint-to-point communication system there is provided a novel frequency to phase converter, for automatically synchronizing the PN codes of the user transmitters/receiver with the receiver/transmitter in the central hub. The highly accurate frequency to phase converter generates a highly accurate phase error signal for synchronizing the multiuser network. The frequency to phase converter includes a serial adder and a series to parallel converter and a shift register which integrates the highly accurate phase error signal values and produces a highly accurate frequency value which is applied to the input of the resident processor in the central hub transmitter/receiver. The central hub transmitter/receiver calculates the clock offset for synchronizing each of the user receiver transmitters and generates a clock adjusting signal which is transmitted to the user receiver/transmitters.