Nested QPSK Encoding for Information Theoretic Security
; Harrison, W. K. Harrison
; Vilela, J.P.
Nested QPSK Encoding for Information Theoretic Security, Proc IEEE Communications Society IEEE International Conference on Communications ICC, Kansas City, United States, Vol. , pp. - , May, 2018.
Digital Object Identifier:
This paper proposes a method to provide secrecy for digital communications with arbitrarily large quadrature amplitude modulation (QAM) constellations for transmission over a Gaussian fading wiretap channel. This is accomplished by breaking the constellation down into nested quadrature phase-shift keying (QPSK) symbols and randomizing the assignment between message bits and modulated symbols using channel state information (CSI). If enough random bits can be generated from CSI it becomes possible to uniquely map an arbitrary message to any symbol in the large QAM constellation. The proposed method can thereby provide perfect secrecy while maintaining high reliability by exclusively assigning minimum-distance-mapped constellations through the randomization for use by the legitimate decoder.