Fig. 8

Outage probability versus channel gain between relay and destination with two relays. The figure shows that the simulations on outage probability versus channel gain between relay and destination (R-D) of partial transmission (PT) and three conventional cooperative strategies, direction transmission (DT), selective decode-and-forward (SDF), and amplify-and-decode (AF), on the situations with two-relaying system. To simulate the unreliable relays, the simulation parameters are set as follows: the number of information bits is 100,000; the transmit SNR of source is 20 dB; other channel states from relays to destination (R-D) and source to destination (S-D) are set the same, as 0.1. In Fig. 8, in order to facilitate the analysis, we assume that the two R-D channels follow the same distribution. As the channel gain between relays and destination increases, the gain value that PT gets better than SDF is nearly half of it in one-relaying system, where the certain amount of location information of PT degrades some performance. Generally speaking, when the R-D channel is better than the severely attenuated S-D channel, i.e., the relays are considered to be unreliable, the performance of PT is better than that of the conventional strategies