Patent ID: 9094125
Filing Date: 2015-07-28
Classification: H04B,H04L

Abstract:
1. A method for optical data transport, comprising: formulating a signal constellation using a D-dimensional optimum signal constellation design (OSCD) method, wherein D is an integer, the method comprising including: determining a D-dimensional optimum source distribution for a given optical channel using an Arimoto-Blahut algorithm; generating D-dimensional training sequences from the optimum source distribution, with the D-dimensional training sequences being split into D-dimensional clusters of points; determining new signal constellation points as the center of mass for each D-dimensional cluster of points; and repeating the formulating steps until convergence or until a predetermined number of iterations has been reached; encoding one or more streams of input data using one or more low density parity check (LDPC) encoders; mapping one or more encoded data streams to symbols, wherein a mapper is configured to assign bits of the symbols to one signal constellation and to associate the bits of the symbols with signal constellation points; generating signal constellation points using a D-dimensional optimum signal constellation design (OSCD) method, storing coordinates obtained by the D-dimensional OSCD method for a plurality of optical signal to noise ratio (OSNR) values in a look-up-table (LUT); selecting a point from the LUT using encoded data streams; inputting the coordinates into a D-dimensional modulator after digital-to-analog conversion (DAC); and transmitting a modulated signal over a fiber-optic medium of interest.