Christoph Lange

Power efficiency of optical versus electronic access networks

Based on a model of a typical operator network we have compared the power consumption of different broadband access technologies and architectures especially DSL, FTTN + VDSL and FTTH. Even though power management improves the performance there is still clear advantage of FTTH with respect to energy efficiency.

Iteratively Detected MIMO-OFDM Twisted-Pair Transmission Schemes

Crosstalk between neighbouring wire pairs in multi-pair copper cables is an important disturbance, which essentially limits the transmission quality and the throughput of such cables. For high-rate transmission, often the strong near-end crosstalk (NEXT) disturbance is avoided or suppressed and only the far-end crosstalk (FEXT) remains as crosstalk influence. In this contribution the FEXT impact in iteratively detected MIMO-OFDM transmission schemes is studied. Extrinsic information transfer (EXIT) charts are used for analyzing and optimizing the convergence behaviour of the iterative demapping and decoding. Our results show that FEXT is not necessarily a limiting factor if appropriate signal processing strategies are used.