Probing capacity

Himanshu Asnani, Haim Permuter, Tsachy Weissman

Research output: Contribution to journalArticlepeer-review

30 Scopus citations


We consider the problem of optimal probing of states of a channel by transmitter and receiver for maximizing rate of reliable communication. The channel is discrete memoryless (DMC) with i.i.d. states. The encoder takes probing actions dependent on the message. It then uses the state information obtained from probing causally or noncausally to generate channel input symbols. The decoder may also take channel probing actions as a function of the observed channel output and use the channel state information thus acquired, along with the channel output, to estimate the message. We refer to the maximum achievable rate for reliable communication for such systems as the Probing Capacity. We characterize this capacity when the encoder and decoder actions are cost constrained. To motivate the problem, we begin by characterizing the trade-off between the capacity and fraction of channel states the encoder is allowed to observe, while the decoder is aware of channel states. In this setting of 'to observe or not to observe' state at the encoder, we compute certain numerical examples which exhibit a pleasing phenomenon, where encoder can observe a relatively small fraction of states and yet communicate at maximum rate, i.e., rate when observing states at encoder is not cost constrained.

Original languageEnglish
Article number5967910
Pages (from-to)7317-7332
Number of pages16
JournalIEEE Transactions on Information Theory
Issue number11
StatePublished - 1 Nov 2011


  • Actions
  • Gel'fand-Pinsker channel
  • Shannon channel
  • channel with states
  • cost constraints
  • probing capacity

ASJC Scopus subject areas

  • Information Systems
  • Computer Science Applications
  • Library and Information Sciences


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