Abstract: A joint AMC-HARQ (hybrid automatic repeat-request) algorithm for TEDS was proposed in this paper. Threshold fixed algorithm based SNR method was adopted in the AMC procedure to select the appropriate modulation and coding scheme; and majority-logic decoding was used in the combining procedure of retransmitted data blocks. Simulation results verify that the proposed algorithm can effectively improve the reliability of data transmission. When the maximum number of retransmission is 2, frame error rate decreases from 36.49% to 6.93%.