  We formulate a model for intermittent communication that can capture bursty
transmissions or a sporadically available channel, where in either case the
receiver does not know a priori when the transmissions will occur. Focusing on
the point-to-point case, we develop a decoding structure, decoding from pattern
detection, and its achievable rate for such communication scenarios. Decoding
from pattern detection first detects the locations of codeword symbols and then
uses them to decode. We introduce the concept of partial divergence and study
some of its properties in order to obtain stronger achievability results. As
the system becomes more intermittent, the achievable rates decrease due to the
additional uncertainty about the positions of the codeword symbols at the
decoder. Additionally, we provide upper bounds on the capacity of binary
noiseless intermittent communication with the help of a genie-aided encoder and
decoder. The upper bounds imply a tradeoff between the capacity and the
intermittency rate of the communication system, even if the receive window
scales linearly with the codeword length.
