In　view　of　the　application　of　a　visible　light　positioning　system　in　a　public　indoor　environment　with　numerous　light　emitting　diodes　(LEDs),　a　long　delay　is　one　of　the　main　factors　that　limits　the　performance　of　the　positioning　systemwith　a　moving　device.　To　solve　this　problem,　a　multiple　access　scheme　based　on　block　encoding　time　division　multiplexing　(TDM)　is　proposed　in　this　paper.　In　our　scheme,　nine　LEDs　compose　one　block　to　reduce　the　system　delay.　Meanwhile,　in　order　to　reduce　intercell　interference,　an　extended　binary　coded　decimal　code　is　used　to　encode　signals　transmitted　by　LEDs.　The　feasibility　and　performance　of　the　scheme　is　demonstrated　by　simulations.　The　results　show　that　the　proposed　TDMscheme　provides　a　better　performance　than　the　conventional　TDM　and　is　more　applicable　to　the　accurate　positioning　of　a　moving　device.　©　2009-2012　OSA.