Patent ID: 6636550
Filing Date: 2003-10-21
Classification: H04B

Abstract:
A bi-directional transmission/receiving system for time division communicating a signal in two directions between first and second transmitter/receivers, the signal being modulated using a spread spectrum method, the system comprising:a first transmitter/receiver and a second transmitter/receivers; a transmitting transmitter/receiver of said first and second transmitter/receivers transmits transmission data containing a pilot carrier and a communication carrier that follows said pilot carrier and transmits the transmission data in a transmission period during an initial synchronization state, which is the until synchronization between said first and second transmitter/receivers that are not synchronized is established; said pilot carrier contains synchronization data for allowing a receiving transmitter/receiver of said first and second transmitter/receivers to establish synchronization of transmission spread spectrum signal; and said communication carrier contains communication data having information data, wherein the transmission data is exchanged between the first and second transmitter/receivers, the first and second transmitter/receivers shift from being in the initial synchronization state in which the first and second transmitter/receivers are not synchronized to being in a normal receiving state in which the first and second transmitter/receivers are communicating spread spectrum signals, and the pilot carrier is kept being sent in the initial synchronization state for a longer time than in the normal receiving state.