The　differential　chaos　shift　keying　with　code　index　modulation　(CIM-DCSK)　using　Walsh　codes　can　increase　the　data　rate,　but　error　rate　performance　degrades　over　practical　multipath　channel　with　high　delay　spread.　To　tackle　this　drawback,　this　paper　proposes　a　parallel　CIM-DCSK　(PT-CIM-DCSK),　where　the　first　time　slot　is　used　to　transmit　the　chaotic　reference　sequence,　and　the　second　slot　is　used　to　transmit　the　multiple　sequences　carrying　data　bits.　In　particular,　multiple　q　chaotic　sequences　are　added　for　data　transmission　in　parallel,　and　each　sequence　is　modulated　by　CIM-DCSK　with　mc　bits.　By　exploiting　the　quasi-orthogonal　characteristics　of　permuted　chaotic　signals,　the　interference　between　q　sequences　can　be　remarkably　suppressed.　In　this　way,　given　the　data　rate,　PT-CIM-DCSK　can　achieve　a　larger　length　of　Walsh　segment　than　the　CIM-DCSK,　since　its　parallel　transmission　compensates　the　rate.　In　addition,　the　error　performance　of　the　proposed　scheme　over　the　multipath　Rayleigh　fading　channel　is　theoretically　analyzed.　The　theoretical　and　consistent　simulation　results　demonstrate　that　the　PT-CIM-DCSK　can　obtain　significant　performance　gains　over　the　conventional　CIM-DCSK,　and　the　gain　can　be　up　to　5　dB　in　multipath　fading　channel　with　high　delay.　This　is　because　the　larger　Walsh　segment　of　PT-CIM-DCSK　provides　the　enhanced　robustness　against　multipath　effect.　The　performance　superiority　of　the　proposed　scheme　is　further　verified　in　practical　ultra-wideband　(UWB)　wireless　industrial　scenarios,　which　suggests　promising　for　low-cost　and　low-complexity　wireless　communication　applications.　©　1972-2012　IEEE.