Patent ID: 6304353
Filing Date: 2001-10-16
Classification: H04B

Abstract:
A method for providing an improved signal to noise ratio (SNR) in an optical transmission system comprising the steps of:providing a first URZ coded representation of data to be transmitted via said optical transmission system and applying said first URZ-coded data to modulate a first aspect of an optical carrier signal transmitted via said optical transmission system;providing a second URZ coded representation of said data to be transmitted and applying said second URZ coded data to modulate a second aspect of said optical carrier signal, wherein said second URZ coded data is delayed relative to said first URZ coded data by a predetermined amount;providing a UNRZ coded representation of said data to be transmitted and applying said UNRZ coded data to modulate a third aspect of said optical carrier signal;at a receiving location for said optical transmission system, causing said transmitted first URZ, said second URZ and said UNRZ modulated signals to be demodulated;summing said demodulated first URZ coded data and said demodulated second URZ data; andcombining said demodulated UNRZ data with said sum of said demodulated first URZ coded data and said second URZ coded data.