Sep of cooperative systems using Amplify and Forward or Decode and Forward relaying

In this paper, we derive the Symbol Error Probability (SEP) of cooperative systems using Amplify and Forward (AF) or Decode and Forward (DF) relaying. In AF relaying, each relay amplifies and retransmits to the destination the received signal from source. The destination combines the signals received from all relays and the source using aMaximum Ratio Combining (MRC) strategy. For DF relaying, each relay decodes the received signal. It forwards the decoded symbol if it decodes correctly. Otherwise, it remains idle. In DF relaying, two protocols are presented. In the first one, each relay decodes only the received signal from the source. In the second one, each relay combines the signals received from the source and the previous m relays. Exact and asymptotic SEP of AF and DF relaying are derived and compared to simulation results.