Based　on　Walsh　Codes　(WC),　a　chaotic　multi-access　transmitting　system,　called　differentially　differential　chaos　shift　keying　(DDCSK)　multi-access　(DDCSK-WC),　has　been　proposed　recently.　The　DDCSK-WC　enhances　error　performance　and　robustness　against　inter-symbol-interference　in　a　multi-path　fading　channel　compared　to　the　conventional　DCSK-WC　system.　As　for　the　demodulation　of　DDCSK-WC,　this　paper　presents　an　improved　detector　at　the　receiver　by　adopting　Bahl,　Cocke,　Jelinek,　and　Raviv　(BCJR)　decoding　algorithm.　We　show　that　the　proposed　BCJR　detector　can　obtain　a　performance　gain　about　2　dB　over　the　convention　detector　used　in　DDCSK-WC,　while　retaining　its　hardware　complexity　almost　unchanged.　The　theoretical　and　simulated　noise　performances　of　the　proposed　system　demonstrate　their　high　consistence.　©　2015　IEEE.