Bi-directional transmitter/receiver system and bi-directional transmitter/receiver

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/receiver;
• a transmitting transmitter/receiver of said first and second transmitter/receivers transmits transmissions 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 state 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 first and second transmitter/receivers each have a number of channels usable for communication, and
• at least one of the first and second transmitter/receivers detects, through a search, an empty channel from among the number of channels either in advance or while being in a data transmission/receiving mode so that the empty channel detected is used for data transmission/receiving.

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/receiver;
• 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 state 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 date,
• wherein the first and second transmitter/receiver of the first and second receiving transmitter/receivers starts counting a predetermined time upon starting sending data to the transmitter/receiver of the first and second transmitter/receivers,
• the receiving transmitter/receiver of the first and second transmitter/receiver also starts counting a time of a same length as the predetermined time upon starting receiving the data, and
• the first and second transmitter/receivers both reverse transmission/receiving states after the predetermined time has elapsed.

A transmitter/receiver for time division communicating a signal in two directions with a paired transmitter/receiver, the signal being modulated using a spread spectrum method, the transmitter/receiver comprising:

• a transmitter/receiver transmits transmission data to the paired transmitter/receiver, the transmission data containing a pilot carrier and a communication carrier that follows said pilot carrier;
• the transmitter/receiver transmits the transmission data in a transmission period during an initial synchronization state, which is the state until synchronization between the transmitter/receiver and the paired transmitter/receiver that are not synchronized is established;
• said pilot carrier contains synchronization data for allowing the paired transmitter/receiver to establish synchronization of transmission spread spectrum signal;
• and
• said communication carrier contains communication data having information data, wherein
• the transmitter/receiver shifts from being in an initial synchronization state in which the transmitter/receiver is not synchronized with the paired transmitter/receiver to being in a normal receiving state in which the transmitter/receiver communicates spread spectrum signals with the paired transmitter/receiver,
• the data which the transmitter/receiver sends to the paired transmitter/receivers in the initial synchronization state and the normal receiving state includes the pilot carrier and the communication carrier, and
• the pilot carrier is kept being sent in the initial synchronization state for a longer time than in the normal receiving state.