Patent ID: 8107826
Filing Date: 2012-01-31
Classification: H04B

Abstract:
1. A method of transmitting digital information over an optical channel, comprising the steps of: processing input digital information bits to generate a corresponding electrical orthogonal frequency division multiplexed (OFDM) signal waveform; applying a modulation to intensity of an optical carrier corresponding with the electrical OFDM signal waveform to produce an optical signal, the modulation having an amplitude and a bias level selected such that negative excursions of a waveform of the optical signal are clipped at a minimum output optical power level whereby said optical signal waveform is asymmetrically-limited in amplitude; and transmitting the optical signal over the optical channel to a receiver which comprises an optical intensity detector, wherein the modulation amplitude and bias level are selected such that an increase in the bias level and/or a decrease in the amplitude to reduce clipping at the minimum output optical power level results in a corresponding reduction of quality of an OFDM signal of equivalent optical power detected at the receiver by the optical intensity detector.