Focusing　on　the　problem　that　differential　spatial　modulation　(DSM)　couldn＇t　obtain　transmit　diversity　and　has　high　decoding　complexity,　a　new　differential　spatial　modulation　scheme　based　on　the　orthogonal　space-time　block　code　was　proposed　and　the　proposed　scheme　is　called　OSTBC-DSM.　There　were　two　matrices　in　this　scheme:　the　spatial　modulation　matrix　and　the　symbol　matrix.　The　former　was　aimed　to　activate　different　transmit　antennas　by　setting　the　position　of　nonzero　elements,　and　the　latter　structured　symbolic　matrix　by　using　orthogonal　space-time　block　codes　(OSTBC)　as　the　basic　code　block.　The　proposed　scheme　could　obtain　full　transmit　diversity　and　higher　spectral　efficiency　compared　with　the　conventional　DSM　schemes.　Moreover,　the　OSTBC-DSM　supported　linear　maximum　likelihood　(ML)　decoding.　The　simulation　results　show　that　under　different　spectral　efficiencies,　the　proposed　OSTBC-DSM　scheme　has　better　bit　error　rate　(BER)　performance　than　other　schemes.　©　2017,　Editorial　Board　of　Journal　on　Communications.　All　right　reserved.