Design of a Tailorable Physical Layer Security Framework Including Alternating Space-Time Coding and Gray Code Hopping
Abstract
A physical layer security framework is developed that may be tailored to a particular wireless communications link. Alternating space-time coding and Gray code hopping techniques are presented that may be implemented individually or concurrently. The first technique may be utilized in any multiple-input multiple-output system with choice of single- or multi-space-time code configurations. Orthogonal, non-orthogonal, and spatially-multiplexed space-time codes are included to achieve a desired diversity-multiplexing balance in addition to demonstrated security benefits. Gray code hopping may be used in any system with common digital modulation schemes to "hop" between alternative binary reflected Gray code mappings of bits to complex-valued modulation symbols. Unlike similar constellation remapping techniques, Gray code hopping provides improved physical layer security against plaintext attacks without sacrificing bit error rate performance. To facilitate these schemes, we present two series of algorithms that systematically build large sets of unique alternative space-time codes and modulation mappings. Decoding methods are discussed to allow for channel equalization and symbol co-phasing when employing an alternating space-time code. Equivalent modulation/demodulation approaches are provided for Gray code hopping. Information-theoretic and computational security analysis, Monte Carlo simulations, and over-the-air testing are completed as confirmation of proposed methods.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 2021
- Accession Number
- AD1150904
Entities
People
- Michael R. Cribbs
Organizations
- Naval Postgraduate School