Backscatter interrogators, communication systems and backscatter communication methods

Abstract

The present invention provides backscatter interrogators, communication systems and backscatter communication methods. According to one aspect of the present invention, a backscatter interrogator includes a data path configured to communicate a data signal; a signal generator configured to generate a carrier signal; and a modulator coupled with the data path and the signal generator, the modulator being configured to spread the data signal to define a spread data signal and amplitude modulate the carrier signal using the spread data signal, the modulator being further configured to phase modulate the carrier signal.

1 - 47 . (canceled)  
     
     
         48 . A backscatter communication system comprising: 
 an interrogator configured to spread a data signal to create a spread data signal, amplitude and phase modulate a carrier using the spread data signal to create a band-limited, modulated signal having a suppressed carrier, and communicate the band-limited, modulated signal; and    an electronic device configured to receive the band-limited, modulated signal and to output a backscatter reply signal to the interrogator.    
     
     
         49 . The backscatter communication system of  claim 48 , wherein the interrogator selectively inverts the spread data signal.  
     
     
         50 . The backscatter communication system of  claim 49 , wherein an inverted spread data signal is used to phase modulate the carrier.  
     
     
         51 . The backscatter communication system of  claim 48 , wherein the spread data signal is selectively inverted using a pseudo-noise signal.  
     
     
         52 . The backscatter communication system of  claim 48 , wherein a tri-level signal is used to phase modulate the carrier.  
     
     
         53 . The backscatter communication system of  claim 52 , wherein the spread data signal is inverted and the tri-level signal corresponds to an inverted spread data signal.  
     
     
         54 . The backscatter communication system of  claim 53  wherein the spread data signal is inverted when the spread data signal corresponds to a predetermined value.  
     
     
         55 . The backscatter communication system of  claim 54 , wherein the predetermined value is a logical low value in the spread data signal.