Technologies

Other Categories

Power devices

This technology is an algorithm designed to enhance power allocation in multichannel, orthogonal frequency division multiplexed (OFDM) telecommunications systems that use discrete multitone (DMT) protocol, among others. DMT includes all asymmetrical digital subscriber line (ADSL) systems and residential DSL systems. The algorithm serves to improve the achievable data rate or the signal-to-noise ratio (SNR), reducing errors in the transmission, and can be used for any OFDM system where the SNR varies across channels.
This technology is a method to eliminate voltage overshoot in cables used to connect AC electric motors and pulse width modulation (PWM) inverters.  As a function of cable length and voltage rise time, voltage overshoot occurs when high frequency currents reflect between the motor and source ends of a cable.  University of Illinois researchers have devised a compensator that shapes the output of the PWM inverter in order to eliminate these reflections; the method only requires knowledge of the transmission line characteristic impedance and propagation delay.  This technique e
print