Can Shannon's channel capacity be challenged?

Abstract

There are one source s(t), one jammingj(t), and two outputs xl( t ) and xl ( t ) . The channel coefficients h, are neither known, nor can be identified by usual techniques because the jamming is uncoordinated with the signal. We study two channel capacities: C, the Shannon capacity whenj(t) is Gaussian; and C?, the optimal channel capacity when j ( t ) = 0. We first show that the Shannon capacity C can be achieved by a blind technique. Can the optimal channel capacity C? be achieved even when j ( t ) f O? If so, the Shannon capacity will be broken because C' 7 C whenj(t) f 0. We will show that there is sufficient information in the output from which C' can be achieved. The latest findings will be presented at the Conference.