Multi(Six)-port impulse radio for ultra-wideband

Multi(six)-port impulse radio (MIR) validates the full channel (3-4 GHz) novel quaternary phase spectrum modulation (QPSM) scheme using a six-port modulator and demodulator circuits. Due to the lack of a monocycle generator, a 1-GHz spectral phase channel is generated from a rectangular pulse signal, upconverted using filters, mixer, and a local oscillator. The 3-4-GHz signal is applied to the RF input of a six-port modulator and digital data is simultaneously fed to a switch matrix terminating four ports of the modulator with either a short or open circuit. This operation produces an output signal in the QPSM scheme. One input port of the six-port demodulator is fed with the received phase-modulated signal and a second input port is fed with the reference nonmodulated signal. The demodulator´s four outputs provide signals of different amplitudes used to determine the modulation states with digital signal processing (DSP) algorithms. Modulation algorithms, demodulation algorithms, and synchronization control are implemented on a field-programmable gate-array-based DSP platform fitted with four analog-to-digital converters. Measurements and simulation results are presented to validate the MIR hardware and software in an operating 1-GHz ultra-wideband channel.