Patent ID: 8234549
Filing Date: 2012-07-31
Classification: H03M,H04B

Abstract:
1. A method comprising the steps of: estimating quadrature amplitude modulated QAM symbols in an LDPC encoded OFDM signal for transmission; performing channel estimation to determine channel estimates in reception of the LDPC encoded OFDM signal; and obtaining channel information for use in detection and decoding of the LDPC encoded signal, wherein the estimated QAM symbols are related to the channel distortion introduced by fiber optical signals, phase shift of the QAM symbols due to chromatic dispersion and self-phase modulation and wherein a λ-configuration, denoted as t-(v,k,{0, 1, . . . λ}), is a collection of k-subsets (blocks) of a v-set V such that every t-subset of V is contained in at most λ of the blocks and let λ