Journal of Optical Communications and Networking Journal of Optical Communications and Networking Flexible resource provisioning of polarization independent coherent PONs based on non-orthogonal multiple access and multiCAP modulation Izquierdo David Altabas Jose A. Barrio Miguel Universidad de Zaragoza Clemente Jesus Millan Pablo Sarmiento Samael Lazaro Jose A. Rommel Simon Puerta Rafael Vegas-Olmos Juan J. Tafur Monroy Idelfonso Garces Ignacio 2021 research-article