Asymptotic analysis of multi-branch two-way amplify-and-forward relaying in Nakagami-m fading with arbitrary fading parameter

Two-way relay networks have received lots of attention, thanks to its ability to overcome the loss in the spectral efficiency due to half-duplex transmission. Asymptotic performance analysis can provide valuable insights in- to practical system designs. However, this is a gap in two-way relay network. In this paper, the asymptotic performance is studied for multi-branch dual-hop two-way amplify-and-forward （AF） relaying networks in independently but not necessarily identically distributed （i.n.i.d.） Nakagami-m fading channels, with arbitrary m 〉 5. The approximate prob- ability density function （PDF） of the instantaneous dual-hop link power at high SNR region is derived. Then we present the asymptotic outage probability expression, and analyze the diversity order and coding gain. Simulations are per- formed to verify the tightness of the presented analysis at medium and high SNR regions.

Joint relay selection and power allocation algorithm in two-way relay networks with proportional fair constraint

In this paper, we consider the joint relay selection and power allocation problem for two-way relay systems with multiple relay nodes. Traditionally, relay selection schemes are primarily focused on selecting one relay node to maximize the transmission sum rate or minimize the outage probability. If so, it is possible to cause certain relay nodes overloaded. In addition, the joint relay selection and power allocation problem is a mixed integer program problem and prohibitive in terms of complexity. Therefore, we propose a novel low complexity joint relay selection and power allocation algorithm with proportional fair scheduling to get the load-balancing among potential relays. Simulation results turn out that, compared with round-robin schemes and max sum rate schemes, the proposed algorithm can achieve the tradeoff between system transmission sum rate and load-balancing.