In the absence of accurate channel probability distribution information or in broadcast scenarios, code design for consistent channel-by-channel performance, rather than average performance, may be desirable. Root and Varaiya’s compound channel theorem promises the existence of universal codes that operate with a consistent proximity to channel mutual information on any instance of the compound...

A compound exponential-server timing channel consists of a number of infinite-buffer single-server queues in tandem. The message is coded in the sequence of arrival times to the first queue. We consider the performance of a structurally simple mismatch decoder that is the maximumlikelihood decoder for a single queue.

In classical information theory it is well-known that feedback does not improve the channel capacity. We demonstrate that this is not the case in the interactive setting by developing a new coding scheme for interactive communication over the binary symmetric channel (BSC) with feedback that allows recovery of the original communication with vanishing probability of error. More precisely, we sh...

We show that expander codes attain the capacity of the binary-symmetric channel under iterative decoding. The error probability has a positive exponent for all rates between zero and channel capacity. The decoding complexity grows linearly with code length.

This paper highlights security issues that can arise when incorrect assumptions are made on the capabilities of an eavesdropper. In particular, we analyze a channel model based on a split Binary Symmetric Channel (BSC). Corresponding security parameters are chosen based on this channel model, and assumptions on the eavesdroppers capabilities. A gradual relaxation of the restrictions on the eave...