Average Contiguous Duration -- A Novel Metric for Characterizing
Wireless Fading Channels
Abstract – We define the average contiguous duration (ACD) of the
received fading signal as the average time duration during which the
signal envelope contiguously remains within a bounded amplitude
interval. Also, the multi-interval ACD or K-ACD function is defined as
the set of ACD values for K non-overlapping amplitude-intervals whose
union spans the received envelope’s amplitude range. We derive
closed-form expressions of the ACD for Rayleigh, Rice, and Nakagami-m
fading signals, which are widely analyzed in the literature. The derived
expressions hold practical significance for several signal processing
applications such as non-uniform quantization of channel samples for
secret key generation (SKG) in physical layer security (PLS) techniques.
The well-known channel fading metric of average fade duration (AFD) is
shown as a special case of the proposed ACD metric and the proposed
theoretical analysis is validated by simulations.