Exact Soft-Covering Exponent

01/02/2018
by   Semih Yagli, et al.
0

This work establishes the exact exponent for the soft-covering phenomenon of a memoryless channel under the total variation metric. The exponent, established herein, is a strict improvement (in both directions) on bounds found in the literature. This complements the recent literature establishing the exact exponent under the relative entropy metric; however, the proof techniques have significant differences, and we show that the total variation metric yields a more precise high-probability claim, in addition to the standard expected value claim. This result implies new and improved bounds for various problems that use soft-covering as their achievability argument, including new lower bounds for the resolvability exponent and the secrecy exponent in the wiretap channel.

READ FULL TEXT

Please sign up or login with your details

Forgot password? Click here to reset