Implementation of power-efficient ONU for elastic-bandwidth IFDMA-PON uplink by employing polar-coordinate transformed PSK mapping [invited]

We present an implementation of a power-efficient optical network unit (ONU) for elastic-bandwidth coherent interleaved frequency-domain multiple access passive optical network (IFDMA-PON) uplink. The ONU for a 12 Gbps quadrature phase-shift keying (QPSK) signal is implemented on a 40 nm copper CMOS process field programmable gate array. By employing polar-coordinate transformed mapping of the PSK signal, the circuit size of the ONU is drastically reduced. The power consumption of the real-time IFDMA modulation circuit is 0.82 W, which achieves 90% reductionin power consumption compared to conventional OFDMA-PON systems. Finally, elastic-bandwidth QPSK signal generations and error-free detection are experimentally demonstrated: 6 Gbps at ONUs 1 and 2, 3 Gbps at ONU1, and 9 Gbps at ONU2.