In this paper, we extend the Amplify-and-Forward cooperative diversity scheme to the context of impulse radio ultra-wideband. In particular, we present the construction of two families of distributed algebraic space-time codes. The first family is based on totally real cyclic division algebras. The second family encodes the pulses used to transmit one information symbol and permits to achieve high-performance levels with lower complexity. Both families of codes achieve full rate, full diversity with non-vanishing determinants with various numbers of relays. Simulations performed over realistic indoor UWB channel models show important performance gains.