This paper considers communication over a multi-hop Rayleigh block-fading channel, where there is no direct link between the transmission ends, and communication is carried out through the use of multiple cascaded relays, employing the Decode and Forward (DF) strategy. It is assumed that the relays cannot do buffering or apply coding over consecutive transmission blocks, and they can merely re-encode the retried information and forward an encoded version of information to the next hop. In this case, assuming the channel information of each hop is not available at the corresponding transmitter and considering the destination either receives a minimum rate R0 or declare an outage event, a multi-layer coding strategy in addition to a single-layer code of the minimum rate R0 are employed, where the optimal power allocation policy across code layers is derived, leading to the maximum average achievable rate for a given outage probability.
['Simin Keykhosravi', 'Soroush Akhlaghi']
Multi-layer coding strategy for multi-hop block fading channels with outage probability