Capacity of a class of deterministic relay channels

The capacity of a class of deterministic relay channels with transmitter input X, receiver output Y, relay output [Y.sub.1] = f(X, Y), and separate noiseless communication link of capacity [R.sub.0] from the relay to the receiver, is shown to be C([R.sub.o]) = sup min{I(X:Y) + [R.sub.0], I(X:[Y.sub.1])}/p(x) Roughly speaking, every hit from the relay is worth one bit to the receiver until saturation at capacity. Index Terms--Capacity, deterministic relay channel, primitive relay channel.