In this paper, we explore a digital-based solution for the generation of 2.4GHz OSQSK test stimuli. The objective is to reduce the testing costs of ZigBee receivers by enabling their test on a standard digital Automatic Test Equipment (ATE). The proposed strategy relies on the generation of a modulated square wave signal in the intermediate frequency band using a digital tester channel, and the filtering of one of its harmonics to produce the RF signal. Appropriate modulation format has to be encoded in the square-wave signal so that the typical characteristics of a ZigBee signal are present in the chosen harmonic component. A dedicated pre-processing algorithm has been developed to determine this encoding. The proposed strategy is then evaluated through Matlab simulations, taking into account the practical constraints imposed by a standard digital ATE.