In　this　letter,　we　investigate　the　performance　of　protograph-coded　reference　reused　differential　chaos　shift　keying　(DCSK)　systems　to　improve　the　transmission　reliability.　The　traditional　protograph-coded　DCSK　receiver　does　not　take　full　advantage　of　the　reused　chaotic　reference　signals　and　hence　cannot　obtain　desirable　error　performance.　To　solve　this　problem,　we　design　a　new　receiver　architecture　called　weighted　reference　estimation　and　iterative　decoding　(WRE-ID),　which　can　universally　improve　the　performance　of　protograph-coded　reference　reused　DCSK　systems　over　both　multipath　Rayleigh　fading　and　additive　white　Gaussian　noise　channels.　In　particular,　we　put　forward　the　WRE　algorithm　to　estimate　reference　signal　in　order　to　calculate　log-likelihood　ratio　(LLR)　more　precisely.　Furthermore,　extrinsic　information　output　from　the　decoder　is　utilized　to　iteratively　recalculate　the　weight　of　the　WRE　algorithm.　As　a　further　illustration,　we　derive　the　LLR　expressions　of　the　proposed　WRE-ID-aided　receiver　of　a　typical　protograph-coded　reference　reused　DCSK　(i.e.,　high-efficiency　DCSK)　system.　Analytical　and　simulated　results　show　that　the　proposed　WRE-ID-aided　receiver　can　always　overtake　the　traditional　receivers　in　reference　reused　DCSK　systems.　Hence,　the　protograph-based　reference　reused　DCSK　systems　with　the　proposed　receiver　are　very　promising　for　high-rate　high-reliability　wireless　applications.　IEEE