Power Optimization in Vectored and Non-Vectored G.fast Transmission
12 February 2015
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 need to be optimized to meet power spectral density and maximum 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 i) inaccuracies in the precoder can significantly degrade the performance of vectored transmission, and ii) low complex heuristics for gain scale optimization yield near optimal solutions.Similar conclusions hold for the 212 MHz profile.
