  We build a realistic Simultaneous Wireless Information and Power Transfer
(SWIPT) prototype and experimentally analyse the harvested energy and
throughput trade-off. Both time-switching and power splitting receiver
architectures are implemented, and the performance comparison is carried out.
Systematic SWIPT transmission signal design methods are also considered and
implemented on the prototype. The harvested energy-throughput (E-T) performance
with different transmission signal designs, modulation schemes, and receiver
architectures are evaluated and compared. The combination of the power
splitting receiver architecture and the superposition transmission signal
design technique shows significant expansion of the E-T region. The
experimental results fully validate the observations predicted from the
theoretical signal designs and confirm the benefits of systematic signal
designs on the system performance. The observations give important insights on
how to design a practical SWIPT system.
