Ivan B.

Ivan B. Djordevia, Tucson, AZ US

Patent application number	Description	Published
20100215371	POLARIZATION MODE DISPERSION (PMD) COMPENSATION IN POLARIZATION MULTIPLEXED CODED ORTHOGONAL FREQUENCY DIVISION MULTIPLEXING (OFDM) SYSTEMS - A receiver and method are provided. The receiver includes a detector configured to receive polarization multiplexed coded orthogonal frequency division multiplexing input sequences and generate estimates of unknown transmitted symbols in the input sequences for x- and y-polarization channels with respect to laser phase noise and PMD. A demapper coupled to the detector is configured to partially cancel polarization mode dispersion (PMD) in the input sequences by computing symbol probabilities for the estimates with respect to the laser phase noise, and averaging the symbol probabilities with respect to the laser phase noise. One or more low-density parity-check (LDPC) decoders coupled to the demapper are configured to receive bit probabilities derived from the averaged symbol probabilities and output code words based at least on the bit probabilities. The one or more LDPC decoders iteratively provide extrinsic soft information feedback to the demapper to compensate for the PMD.	08-26-2010

Patent application number	Description	Published
20090297144	POLARIZATION MODE DISPERSION COMPENSATION IN MULTILEVEL CODED-MODULATION SCHEMES USING BLAST ALGORITHM AND ITERATIVE POLARIZATION CANCELLATION - Receivers and methods are provided for polarization mode dispersion compensation in multi-level coded-modulation schemes using a BLAST algorithm and iterative polarization cancellation. A receiver includes a vertical Bell Laboratories Layered Space-Time Architecture (V-BLAST) orthogonal frequency division multiplexing (OFDM) detector configured to receive input sequences and partially cancel polarization interference with respect to the input sequences to output symbol estimates for the input sequences. The receiver further includes one or more low-density parity-check (LDPC) decoders coupled to the V-BLAST OFDM detector configured to receive channel bit reliabilities and output code words. The channel bit reliabilities are indirectly calculated from the symbol estimates. The one or more LDPC decoders iteratively provide extrinsic soft information feedback to the V-BLAST OFDM detector to compensate for the polarization interference.	12-03-2009

Patent application number	Description	Published
20110205512	Active Spectral Control of Optical Source - A method of controlling a spectral property of a light beam includes directing a light beam to a lithography exposure apparatus configured to create a pattern on a wafer; receiving information representative of a spectral property of the light beam; receiving information representative of an optical imaging condition of the lithography exposure apparatus; estimating a characteristic value of the light beam based on the received spectral property information and the received optical imaging condition information; determining whether the estimated light beam characteristic value matches a target light beam characteristic value; and if it is determined that the estimated light beam characteristic value does not match the target light beam characteristic value, adjusting the spectral property of the light beam.	08-25-2011