In　this　paper,　a　novel　detection　algorithm　based　on　variance　detection　(VD)　is　proposed　for　non-coherent　impulse　radio　(IR)　ultra-wideband　(UWB)　receivers.　In　the　VD-based　detection　algorithm,　after　the　received　IR　UWB　signals　are　squared,　their　variance　instead　of　their　mean　is　measure　to　recover　information　bits.　Computer　simulations　show　that　as　compared　to　the　conventional　energy　detection　(ED)　based　receiver,　the　newly　proposed　VD-based　receiver　can　achieve　a　much　better　bit-error-rate　performance　under　both　AWGN　and　multipath　channels.　Furthermore,　unlike　the　conventional　ED-based　receiver,　which　is　vulnerable　to　narrowband　interference　(NBI),　the　VD-based　receiver　has　an　inherent　ability　to　mitigate　the　destructive　effects　caused　by　strong　NBI.