Capacity Bounds for Dirty Paper with Exponential Dirt

The additive exponential noise channel with additive exponential interference (AENC-AEI) known non-causally at the transmitter is studied. This channel can be considered as an exponential version of the discrete memoryless channel with state known non-causally at the encoder considered by Gelfand and Pinsker. We make use of Gelf’and-Pinsker’s classic capacity Theorem to derive inner and outer bounds on the capacity of this channel under a non-negative input constraint as well as a constraint on the mean value of the input. First we obtain an outer bound for AENC-AEI. Then by using the input distribution achieving the outer bound, we derive an inner bound which this inner bound coincides with the obtained outer bound at high signal to noise ratios (SNRs) and therefore, gives the capacity of the AENC-AEI at high SNRs. Keywords-Additive exponential noise; capacity bounds; dirty paper; side information