The Filtered Gaussian Primitive Diamond Channel

TL;DR

This paper analyzes a Gaussian diamond relay channel with frequency response and limited fronthaul, proposing a time-sharing strategy between compress-and-forward and decode-and-forward to optimize data rates.

Contribution

It introduces an optimal time-sharing approach between CF and DF in a frequency-dependent Gaussian diamond relay channel, with derived rate expressions.

Findings

Optimal CF-DF time sharing outperforms superposition methods.

Frequency-dependent power and rate allocations are fully characterized.

Achievable rates are derived using time-sharing between CF and DF.

Abstract

We investigate the special case of diamond relay comprising a Gaussian channel with identical frequency response from the user to the relays and fronthaul links with limited rate from the relays to the destination. We use the oblivious compress and forward (CF) with distributed compression and decode and forward (DF) where each relay decodes the whole message and sends half of its bits to the destination. We derive achievable rate by using time-sharing between DF and CF. It is proved that optimal CF-DF time sharing is advantageous over superposition of CF and DF. The optimal time sharing proportion between DF and CF and power and rate allocations are different at each frequency and are fully determined.