Patent ID: 6094450
Filing Date: 2000-07-25
Classification: H04B

Abstract:
A method for modulating and demodulating a data signal containing one or more data bits, the method comprising the steps of:generating a pilot PN sequence;generating a symbol PN sequence having an epoch synchronized to an epoch of the pilot PN sequence;producing a plurality of delayed versions of the symbol PN sequence, each delayed version of the symbol sequence having a distinct time offset relative to the pilot PN sequence epoch;selecting from amongst the delayed versions of the symbol PN sequence based on one or more of the data bits in the data signal;modulating a carrier signal with the pilot PN sequence and selected delayed versions of the symbol PN sequence;transmitting the modulated carrier signal through a communication channel; anddemodulating the modulated carrier signal to recover the data signal, by correlating the delayed symbol sequence from the carrier signal with one or more delayed versions of the symbol PN sequence.