Ergodic Layered Erasure One-Sided Interference Channels

The sum capacity of a class of layered erasure one-sided interference channels is developed under the assumption of no channel state information at the transmitters. Outer bounds are presented for this model and are shown to be tight for the following sub-classes: i) weak, ii) strong (mix of strong but not very strong (SnVS) and very strong (VS)), iii) ergodic very strong (mix of strong and weak), and (iv) a sub-class of mixed interference (mix of SnVS and weak). Each sub-class is uniquely defined by the fading statistics.

💡 Research Summary

This paper investigates the sum‑capacity of a two‑user one‑sided interference channel (IFC) under the realistic assumption that transmitters have no instantaneous channel state information (CSI); only the receivers know the exact fading realizations. The authors model each link as a “layered erasure” channel: a transmitted q‑bit vector is observed at the receiver after erasing a random number of least‑significant bits. The random erasure depth N (0 ≤ N ≤ q) is the fading state, known only at the receiver. In the one‑sided setting, the cross‑link from transmitter 2 to receiver 1 is absent (N₁₂ = 0), so only receiver 2 experiences interference.

The analysis proceeds in two steps. First, the authors derive the capacity region of a two‑user layered erasure multiple‑access channel (MAC) with a single receiver. They show that the individual rates are bounded by the expected number of received layers, E