Pseudo-coherent software defined Ultra wideband transmitter for ranging and communication

In this paper a pseudo-coherent software-defined impulse-radio (IR) transmitter for the Ultra wideband (UWB) technology is presented. Due to the large available bandwidth, the transmitter is perfectly suited for implementing and testing high precision ranging and positioning systems in dense multi-path indoor environments. Simultaneously, it can offer reliable and secure communication functionalities. A pseudo-coherent transmitter offers the possibility to evaluate the phase information of the carrier frequency in the receiver, in order to improve ranging accuracy or provide additional modulation schemes. The software-defined radio (SDR) solution gives the opportunity to examine arbitrary modulation schemes, communication protocols, impulse shapes or predistortion techniques. The prototype of the transmitter is based on a multi-Nyquist digital to analog converter (DAC) and a field programmable gate array (FPGA) connected to a personal computer (PC) via Universal Serial Bus (USB) interface. Two different approaches for up-conversion to UWB frequency bands are presented and compared to each other.