Real-Time MIMO Discrete Multitone Transceiver Testbed

Given a wireline transmitter/receiver pair with fixed parameters (modulation and coding methods, transmission, bandwidth, receiver noise floor, etc.) that achieves a certain bit rate on a single pair of wires, one might expect that using two pairs of wires (and two sets of transceivers) would double the bit rate. However, the presence of crosstalk induced by the coupling of the energy across the wire pairs may cause significant reduction in the expected bit rate. In this paper, we present a multiple-input multiple-output (MIMO) discrete multitone (DMT) system that achieves double the bit rate of a traditional single transmitter- receiver system when using 2 transmitters and 2 receivers operating over two wires. The improvement has been achieved both in desktop simulation and in a real-time testbed. The testbed also allows rapid exploration of many design tradeoffs in a DMT system.