Combined bulk and per-tone relay selection in cooperative OFDM systems

In this paper, we propose a combined bulk and per-tone transmission scheme for distributed cooperative decode-and-forward OFDM system. A subset L out of N available relay nodes is first chosen and then per-tone selection is performed within the subset. An approximated expression for the outage probability of proposed scheme is given. Monte Carlo simulations validate our analysis and show the performance compared with existing schemes. The proposed scheme outperforms the bulk based relay selection scheme, with a modicum of complexity compared with per-tone based relay selection scheme.