Average achievable rate of broadcast strategy in relay-assisted block fading channels

作者：Baghani Mina; Akhlaghi Soroush^*; Golzadeh Valiulah

来源：IET Communications, 2016, 10(3): 346-355.

DOI：10.1049/iet-com.2015.0555

• relay networks (telecommunication)
• Rayleigh channels
• broadcast communication
• decode and forward communication
• amplify and forward communication
• telecommunication signalling
• average achievable rate
• broadcast strategy
• relay-assisted block fading channels
• two-hop transmission
• channel gains
• source-to-relay
• relay-to-destination
• signalling method
• multilayer code
• decode-and-forward strategy
• amplify-and-forward strategy
• DF strategy
• AF strategy
• peak power constraint

This study concerns two-hop transmission over relay-assisted block fading channels, assuming there is no direct link between transmission ends and the communication is carried out through using a relay. It is assumed that the channel gains from source-to-relay and relay-to-destination are known at the relay, while the source is unaware of channel gains. In this case, it is demonstrated that the best signalling method is using a multi-layer code at the first hop, while using a single-layer code at the second hop. Accordingly, the decode-and-forward (DF) and amplify-and-forward (AF) strategies at the relay are investigated, where for DF strategy under two special cases of peak power and average power constraints, the optimal power allocation policy across coding blocks are devised. Moreover, for AF strategy the optimal weight function maximising the average signal-to-noise ratio at the destination is derived. The simulation results for Rayleigh fading environment demonstrate the superiority of DF over AF in terms of the average achievable rate. More specifically, it is demonstrated that the broadcast approach in DF strategy under average power constraint closely follows the so-called broadcast cutset upper bound, thereby providing favourable results in such network.

• 出版日期2016-2-11