Performance analysis in wireless key generation using estimated channel state information

A secret key can be generated between two legitimate parties from observations of the common wireless channel. However, key disagreement usually occurs due to the estimation errors. Considering a guard band, the key disagreement rate (KDR) is firstly derived in a closed‐form expression. Although increasing the size of the guard band can decrease KDR; the length of the raw key bit sequence is also shortened. To evaluate such an effect, the raw key generation rate is defined and derived. The simulation results verify the theoretical analysis and are useful for the determination of pilot power and guard band size.