How Many Queries Will Resolve Common Randomness?
How Many Queries Will Resolve Common Randomness?
复制标题
有多少查询可以解决常见的随机性?
DOI:
10.1109/isit.2013.6620809
复制
发表时间:
2013
影响因子:
2.5
通讯作者:
P. Narayan
中科院分区:
文献类型:
--
作者:
Himanshu Tyagi;P. Narayan
A set of m terminals, observing correlated signals, communicate interactively to generate common randomness for a given subset of them. Knowing only the communication, how many direct queries of the value of the common randomness will resolve it? A general upper bound, valid for arbitrary signal alphabets, is developed for the number of such queries by using a query strategy that applies to all common randomness and associated communication. When the underlying signals are independent and identically distributed repetitions of m correlated random variables, the number of queries can be exponential in signal length. For this case, the mentioned upper bound is tight and leads to a single-letter formula for the largest query exponent, which coincides with the secret key capacity of a corresponding multiterminal source model. In fact, the upper bound constitutes a strong converse for the optimum query exponent, and implies also a new strong converse for secret key capacity. A key tool, estimating the size of a large probability set in terms of Rényi entropy, is interpreted separately, too, as a lossless block coding result for general sources. As a particularization, it yields the classic result for a discrete memoryless source.