Collaborative Covert Communication Design Based on Lattice Reduction Aided Multiple User Detection Method

Abstract

Spread spectrum communication is a typical scheme for covert communication because of its low detectability and antijam characteristic. However, the associated design concerns multiple factors, such as cochannel multiple access interference (MAI) and spread spectrum gain. In this paper, the lattice reduction theory is applied to MAI cancellation of spread spectrum communication and a novel lattice reduction aided multiple user detection method is proposed. The near maximum likelihood (ML) performance of MAI resistance is verified by simulation and theoretical analysis. The superiority of detection performance in strong MAI scenarios is especially addressed. Based on the algorithm, a collaborative covert communication system design is proposed. Low-power covert signals can be transmitted at a higher bit rate with the same coverage as more high-power cochannel signals. The covert transmission performance can be improved significantly compared to traditional designs.

A Multiple‐Access Time and Frequency Spectrum‐Spreading Modulation

“…Different techniques of spread spectrum include frequency-hopping spread spectrum (FHSS), directsequence spread spectrum (DSSS), time-hopping spread spectrum (THSS), chirp spread spectrum (CSS), and in some cases combinations of these forms. For example, in Multicarrier Direct-Sequence CDMA (MC-DS-CDMA) time and frequency spreading is used [3]; also lattice reduction theory and aided multiple user detection is applied to a spread spectrum system leading to near-far effect suppression [4]. A conventional spread spectrum system employs pseudonoise (PN) code generators while other schemes employ nondeterministic spreading codes generated from a random input data stream such as the self-encoded spread spectrum (SESS) [5].…”