System and method for acoustic data transmission

Abstract

Embodiments of the present invention are directed to acoustic data transmission using a spreading code. A system for acoustic data transmission includes an ingestible capsule and an acoustic receiver. The ingestible capsule includes a modulator, a spreader, and an acoustic transmitter. The modulator modulates data according to a modulation scheme. The spreader spreads the modulated data according to a spreading code. The acoustic transmitter acoustically transmits the modulated and spread data through a body of an animal. The acoustic. receiver includes an acoustic transducer a de-spreader and a demodulator. The acoustic transducer receives the acoustically transmitted signal and forms an electrical signal therefrom. The de-spreader de-spreads the received signal in accordance with the spreading code. The demodulator demodulates the received and de-spread signal in accordance with the modulation scheme, wherein a phase of the spreading code is synchronized with the received signal whereby a signal-to-noise ratio of the received signal is increased.

What is claimed is: 
     
         1 . A method for communicating from an ingestible capsule, comprising:
 modulating data from the ingestible capsule according to a modulation scheme;   spreading the modulated data according to a spreading code; and   acoustically transmitting the modulated and spread data through a body of an animal.   
     
     
         2 . The method of  claim 1 , wherein the modulating comprises:
 modulating data from the ingestible capsule according to a phase shift keying (PSK) modulation scheme.   
     
     
         3 . The method of  claim 2 , wherein the modulating comprises:
 modulating data from the ingestible capsule according to at least one of a binary PSK modulation scheme, a multi-level PSK modulation scheme, and a differential PSK modulation scheme.   
     
     
         4 . The method of  claim 2 , wherein the modulating comprises:
 modulating data from the ingestible capsule according to a first order differential PSK modulation scheme and a second order differential PSK modulation scheme.   
     
     
         5 . The method of  claim 1 , wherein the spreading comprises:
 spreading the modulated data according to a Barker spreading code.   
     
     
         6 . The method of  claim 1 , further comprising:
 receiving the acoustically transmitted signal;   de-spreading the received signal in accordance with the spreading code; and   demodulating the received and de-spread signal in accordance with the modulation scheme, wherein a phase of the spreading code is synchronized with the received signal whereby a signal-to-noise ratio of the received signal is increased.   
     
     
         7 . The method of  claim 1 , further comprising:
 receiving the acoustically transmitted signal;   multiplying the received signal by a plurality of spread signals to form a corresponding plurality of received spread signals;   demodulating the corresponding plurality of received spread signals in accordance with the modulation scheme; and forming a final data signal from the plurality of demodulated signals, whereby a signal-to-noise ratio of the final data signal is increased.   
     
     
         8 . The method of  claim 7 , wherein the forming comprising:
 multiplying the plurality of demodulated signals by a corresponding plurality of signal-to-noise coefficients to form a plurality of weighted data signals;   and summing the plurality of weighted data signals to form the final data signal.