Adaptive Wireless Channel Probing for Shared Key Generation Based on PID Controller
Generating a shared key between two parties from the wireless channel is an increasingly interesting topic. The process of obtaining information from the wireless channel is called channel probing. Previous key generation schemes probe the channel at a preset and constant rate without any consideration of channel variation or probing efficiency. In order to satisfy the users' requirements for KGR and to use the wireless channel efficiently, the authors propose an adaptive channel probing scheme based on the Proportional-Integral-Derivative (PID) controller, which is used to tune the probing rate. Moreover, they use the Lempel-Ziv complexity to estimate the entropy rate of channel statistics (Received Signal Strength, RSS), which is considered as an indicator of probing efficiency.