Upconversion of Gain-Switched Laser Pulses for Optical Generation of UWB Signals

We propose and experimentally demonstrate a simple, low-cost optical ultra-wide band (UWB) pulse generation method. A gain-switched laser pulse is dispersed by optical fiber propagation and upconverted to the center of the US Federal Communications Commission (FCC) mask using an optical intensity modulator. The generated UWB pulses comply with the FCC mask with relatively high power efficiencies. We also show that the optical fiber can be replaced with a fiber Bragg grating filter to make the transmitter compact. Wireless propagation of the UWB impulses is investigated by offline signal processing. A linear receiver and an energy detector are implemented. The linear filter shows a better BER performance, particularly in worse channel conditions. We reach the FEC limit of 10-3 after 3.5 m of wireless propagation at 856 Mb/s.