Diamond Channel with Partially Separated Relays
The authors considered several variations of the diamond channel with an orthogonal multiple access component. They established the capacity for the case when the broadcast channel is deterministic. They next provided an upper bound on the capacity when the broadcast channel is physically degraded. This upper bound was shown to be tight for a sub-class of such channels. They next considered the variation of diamond channel where the relays are partially separated and established the capacity when the broadcast channel is physically degraded and semi-deterministic. For both of these cases, they showed that the cut-set bound is tight.