Major non-recurrent geomagnetic storms are generally associated with solar wind (SW) disturbances created by fast coronal mass ejections (CMEs), and most major solar energetic proton events observed near Earth appear to result from the acceleration of SW particles by a CME-driven interplanetary shock (e.g. (1)). We present here a simplified theoretical model which describes the injection of particles and their subsequent acceleration at a fast CME associated shock. The model is fully time-dependent and the particle shock acceleration processes are described dynamically. Energetic or accelerated particles are allowed to escape at same distance upstream of the shock, after which they propagate scatter-free to an observation point. Dynamic spectra and intensity profile are presented. ©1999 American Institute of Physics.