This letter presents a novel transceiver design aimed at enabling Direct-to-Satellite Internet of Things (DtS-IoT) systems based on the long-range frequency-hopping spread spectrum (LR-FHSS). Our focus is on the development of an accurate framing scheme through an analysis of the frame structure and key parameters pertaining to a Long-Range Wide-Area-Network (LoRaWAN). To handle the Doppler effect in DtS-IoT networks and simultaneously enable the reception of numerous frequency hopping signals, a robust signal detector for the receiver is proposed. We verify the performance of the proposed LR-FHSS transceiver design through simulations conducted in a realistic satellite channel environment, assessing several metrics.