A cyclic prefixed single-carrier (CP-SC) relay network incorporating an adaptive decode-and-forward (ADF) protocol is proposed in this paper. For a two-hop ADF protocol, a general expression for the effective end-to-end signal to noise ratio (ESNR) is examined for multiple relays. With the help of a derived probability density function (PDF) for the ESNR, closedform expressions for the outage probability and an asymptotic average symbol error rate (AASER) are obtained. An asymptotic analysis revealing the diversity gain is also performed. Monte Carlo simulations verify these derived analytical results.