Abstract
Recently, the demand of high-speed data access is urgent. Discrete multi-tone (DMT) is one of the key technologies. It can provide broadband services on the existing copper telephone lines. A DMT-based technology called asymmetrical digital subscriber line (ADSL), which can provide downstream data rate up to 8Mbps, and upstream data rate up to 800kbps, has been wildly used. Very high bit-rate digital subscriber line (VDSL) is the latest generation of DSL, which can provide high downstream data rate up to 54Mbps, and upstream data rate up to 6.4Mbps for residential customers and 2.3~34Mbps data rate for businesses.In this thesis, we propose an enhanced RFI cancellation scheme which provides a great improvement of the RFI suppression in VDSL, and can be easily extended to multiple RFI conditions. The simulation results show that the proposed RFI canceller is advantageous since its high performance and less computational complexity. Besides, due to serious FEXT in VDSL transmission systems, UPBO has to be used in VDSL to improve upstream transmission rate. We summarize several UPBO methods and compare their performances.Finally, we set up a simplified DMT-based VDSL transmission system. With the help of a powerful digital signal processor, it’s easy and systematical to carry out a digital communication system.