All digital 1.62 Mb/s QPSK burst-mode system for FTT/VDSL transmission

Abstract

This paper presents an all digital 1.62 Mb/s quadrature phase-shift keying (QPSK;) burst-mode transceiver for fiber-to-the-curb/very-high-rate digital subscriber line (FTTC/VDSL) application. In a point-to-multipoint FTTC/VDSL network architecture, a time division multiple access (TDMA) scheme is used to connect multiple user devices to the network device. We discuss the design and implementation of an all-digital burst-mode QPSK system for transmission of 1.62 Mb/s upstream data over FTTC/VDSL channel environment. All operations of the QPSK system, including power detection, demodulation, box-car filtering, fast/slow-mode carrier and timing recovery, have been realized digitally without multiplication. It is shown by theoretical and computer simulation results that the proposed QPSK transceiver operates on up to 2.5 kft (about 762 m) of 26 gauge cable with a comfortable noise margin.