Propagation characteristics of wideband relay channels in urban environment

In order to evaluate the relay performance for IMT-Advanced systems, the propagation characteristics of relay channels are necessary, especially in urban environments. We conducted wideband relay channel measurements at 2.35 GHz in urban environments of China by employing a real-time channel sounder. Three types of links, i.e. base station to mobile station (BS-MS), relay station to mobile station (RS-MS) and base station to relay station (BS-RS), were measured separately at three sites. Statistical propagation characteristics are presented and compared in this paper, including path loss (PL), root mean square (rms) delay spread (DS), angular spread (AS) and cross-polarization discrimination (XPD). These results are necessary for the technical research and evaluation of the relay system.