Mobile users with single antennas can use spatial transmission diversity through cooperative space-time encoded transmission. This paper presents an end-to-end performance analysis of two-hop asynchronous cooperative diversity with regenerative relays over Rayleigh block-flat-fading channels. We present a preceding frame-based scheme with packet-wise encoding which enables best synchronization and channel estimation. We derive the bit-error rate and the end-to-end bit-error rate expressions for binary phase-shift keying. We present the performance of the frame-error rate and the end-to-end frame-error rate. Finally, comparisons between three system configurations, differing by the amount of cooperation, are presented. The influence of the amount of cooperation is small (about 2dB), Furthermore, simulations show that the analytical results are correct at all SNRs.