Fundamentals of Physical Layer Anonymous Communications: Sender Detection and Anonymous Precoding

In the era of big data, anonymity is recognized as an important attribute in privacy-preserving communications. The existing anonymous authentication and routing designs are applied at higher layers networks, ignoring fact that physical layer (PHY) also contains privacy-critical information. this paper, we introduce concept PHY anonymity, reveal receiver can unmask sender’s identity by only analyzing information, i.e., signaling patterns characteristics channel. We investigate two scenarios, where has more antennas than sender strong case, vice versa case. For each scenario, first detection strategies receiver, then develop precoding to address while guaranteeing high signal-to-interference-plus-noise-ratio (SINR) for particular, interference suppression precoder proposed, assisted a dedicated transmitter-side phase equalizer removing ambiguity. Afterwards, constructive investigated utilize inter-antenna beneficial element without loss anonymity. Simulations demonstrate precoders able preserve simultaneously guarantee SINR, opening new dimension on designs.