Performance of transmission-time optimized relaying schemes in real-world channels

The deployment of relay stations has been proposed as a practical means to increase spectral efficiency in wireless networks. In this paper, we compare the achievable data rates of several relaying schemes using measurements at 2.45 GHz. We investigate the decode-and-forward relay schemes described by Nabar et al. [1], which we extend by additionally optimizing transmit durations. At the transmitters, we distinguish between the availability of instantaneous channel state information and average channel SNR information. Our data analysis indicates that (i) the deployment of relays can improve ergodic data rate at least twofold, (ii) instantaneous channel knowledge enables at most 8.7% increase in spectral efficiency over average channel knowledge, and (iii) relay selection has a large impact on the performance of cooperative networks.