Patent ID: 6035040
Filing Date: 2000-03-07
Classification: H04K

Abstract:
A method of decrypting data comprising:(a) encrypting bit-wise data, using a first bit mask, modulating the data into symbol format, and transmitting the symbol format data to a receiving apparatus,in a receiving apparatus,(b) rotating a current received symbol sample by an amount equal to one of (i) its difference in phase from an immediately preceding received symbol sample toward the phase of the immediately preceding received symbol sample phase, and (ii) by an amount equal to estimated carrier phase towards zero phase,(c) generating a second bit mask subset derived from values of the first bit mask, comprising plural bits for each symbol,(d) reflecting the rotated symbol by a phase defined by the plural bits to form a symbol which is devoid of encryption, and(e) providing the symbol devoid of encryption to a soft-decision decoder.