초록 ▼

A Time Division Multiple Access (TDMA) duplex radio communication system uses an Interrogator to generate a first radio signal by modulating a first information signal onto a radio carrier signal which is sent to at least one remote Tag of the system. The remote Tag receives and modulates a second i

A Time Division Multiple Access (TDMA) duplex radio communication system uses an Interrogator to generate a first radio signal by modulating a first information signal onto a radio carrier signal which is sent to at least one remote Tag of the system. The remote Tag receives and modulates a second information signal onto a second radio carrier signal to form a second modulated signal which is transmitted, in a time-slotted manner, back to the Interrogator. The remote Tag selects, or is instructed, how many times it should repetitively transmit the second modulated signal; and selects, or is instructed, over how many of the time slots following receipt of the first radio signal the remote Tag should repetitively transmit the second modulated signal. Other embodiments use Modulated Backscatter to transmit the second modulated signal, and use homodyne detection to demodulate the second modulated signal. A Frequency Division Multiple Access (FDMA) duplex radio communication system embodiment utilizes multiple subcarrier frequencies and another embodiment combines the FDMA and the TDMA methods. A Code Division Multiple Access (CDMA) embodiment utilizes multiple spreading codes and another embodiment combines the CDMA and the TDMA methods.

대표청구항 ▼

[ We claim:] [1.] A radio communication system comprisingan interrogator includingmeans to generate a first radio signal, andmeans to transmit said first radio signal to at least one tag;said at least one tag includingmeans to receive said first radio signal,means to generate a second modulated sign

[ We claim:] [1.] A radio communication system comprisingan interrogator includingmeans to generate a first radio signal, andmeans to transmit said first radio signal to at least one tag;said at least one tag includingmeans to receive said first radio signal,means to generate a second modulated signal by modulating a multiple bit digital second information signal onto a radio carrier signal,means to divide time into a series of time slots, andmeans to transmit N repetitions of said second modulated signal, where N is two or more, within a certain number of said time slots following the reception of said first radio signal; andsaid interrogator further includingmeans to receive said second modulated signal, andmeans to demodulate said second modulated signal to obtain said second information signal.