Ultra-wideband (UWB) wireless communication systems are based on the transmission of extremely narrow pulses. with a duration inferior to a nanosecond. The application of transmit reference (TR) to UWB systems allows to side-step channel estimation at the receiver. with a tradeoff of the effective transmission bandwidth. https://www.divivoyance.com/product-category/electric-portable-dab-rig-accessory/