Frequency-modulated　differential　chaos　shift　keying　ultrawideband　(FM-DCSK　UWB)　system　has　attracted　more　and　more　attention　in　recent　years　because　of　its　low-complexity　and　low-power　advantages.　Nevertheless,　its　system　performance　is　severely　degraded　in　the　presence　of　narrowband　interference　(NBI),　which　further　limits　its　practical　applications.　In　this　paper,　an　enhanced　energy-based　detector　(EED)　is　proposed　for　the　FM-DCSK　UWB　system　to　tackle　this　problem.　Compared　with　the　conventional　energy　detector　(ED),　the　proposed　EED　significantly　enhances　the　anti-NBI　capability　while　maintaining　the　low-power　and　low-complexity　feature.　As　a　further　insight,　the　analytical　bit-error-rate　(BER)　expression　of　the　proposed　EED-based　FM-DCSK　UWB　system　is　derived　over　additive　white　Gaussian　noise　as　well　as　IEEE　802.15.4a　multipath　fading　channels.　Moreover,　simulation　results　are　carried　out　to　demonstrate　the　accuracy　of　the　theoretical　analysis　and　the　merit　of　the　proposed　EED.　It　is　illustrated　that　the　proposed　EED　achieves　better　performance　than　the　conventional　ED　in　various　transmission　scenarios.　Thanks　to　the　above-mentioned　advantages,　the　proposed　EED-based　FM-DCSK　UWB　system　appears　to　be　an　excellent　candidate　for　low-power　and　low-complexity　tactile　Internet-of-Things　applications,　e.g.,　wireless　sensor　networks　and　wireless　body　area　networks.