Location-privacy-preserving technique for 5g mmwave devices

In fifth generation (5G) cellular networks, a single base station equipped with multiple antennas can determine the user position within centimeters, by processing the wireless millimeter-wave channel estimate. A fake base station serving a victim user can also obtain the user location. In order to protect the user privacy, we propose a technique to prevent localization. We design a user transmit beamformer, so that the angles of departure of each channel path are hidden to the base station, thus preventing localization. We also optimize the allocated power, in order to maximize the achievable rate. The proposed solution is compared with both the capacity-achieving beamforming (without location privacy) and the zero-forcing beamforming, which still provides location privacy, at the cost of a lower rate.