Power Optimization in Vectored and Non-Vectored G.fast Transmission

We extend studies on power optimization in VDSL2 to G.fast, the technology under definition. In vectored G.fast the power of the signals before precoding needs to be optimized to meet power spectral density and maximum aggregate transmit power constraints per line. We formulate this interplay between vectoring and power optimization, with non-vectored transmission as a particular case. Three power allocation algorithms are devised that allow a tradeoff between optimality and computational complexity. Measured channel data from a European operator up to 106 MHz is considered. Numerical evaluation reveals that low complex heuristics for power optimization yield near optimal solutions both with perfect and imperfect channel state information. Similar conclusions hold for the 212 MHz profile.