Wiretap Channel with Rate-Limited Channel State Information

Abstract EN

We revisit a channel coding problem where the channel state information (CSI) is rate-limited (or coded) andavailable to the channel encoder.

A wiretapper is added into this model, and the confidential message is intended onlyfor the legal receiver and should be kept from being eavesdropped by the wiretapper.

Equivocation analysis is providedto evaluate the level of information leakage to the wiretapper.

We characterize an achievable rate-equivocation regionas well as an outer bound for this security model.

To achieve the rate-equivocation triples, we propose an efficientcoding scheme, in which the coded CSI serves as the CSI for the channel encoder, based on Gel’fand and Pinsker’s coding and Wyner’s random coding.

Furthermore, an example of Gaussian wiretap channel with rate-limited CSI ispresented, of which a lower bound on the secrecy capacity is obtained.

By simulation, we find there exists an optimalrate of the coded CSI at which the biggest secrecy transmission rate of the Gaussian case is achieved.