A reconfigurable impulse radio transmitter

To investigate impulse radio (IR) communication transceivers, bit error rate (BER) measurements are typically performed by connecting an arbitrary waveform generator and a digitizing oscilloscope. In this paper a reconfigurable software defined radio (SDR) transmitter specifically designed for IR communication tests is presented. The prototype offers the possibility to transmit arbitrary 4-ary modulated impulses with 1 GHz bandwidth over four channels in the frequency range from 6 GHz-10 GHz. For generation of intermediate frequency (IF) signals a subsampling concept with a multi-Nyquist digital to analog converter (DAC) and a field programmable gate array (FPGA) has been employed. Pseudo-coherent signals are synthesized at radio frequency (RF) by utilizing a mixer with a local oscillator (LO) frequency locked to the LO of the DAC. A comparison of theoretically derived signals and measurements shows that both are in close agreement.