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.