Patent ID: 8472813
Filing Date: 2013-06-25
Classification: H04B,H04L

Abstract:
1. A polarization-multiplexed (POLMUX) optical orthogonal frequency division multiplexing (OFDM) system with direct detection, comprising: an adaptive dual POLMUX carrier OFDM transmitter; and a block symmetric (B-S) MIMO equalizer coupled to the adaptive dual POLMUX carrier OFDM transmitter through a standard single-mode-fiber (SSMF) feedback path, wherein the B-S MIMO equalizer comprises a B-S channel estimator, wherein the B-S channel estimator first uses training sequences in determining an estimation matrix such that the received symbols on subcarriers i and N−i+1 in the polarizations X′ and Y′ can be modeled as: where v and y denote a noise vector and a vector of received symbols, respectively and i=1, 2, . . . N, denotes the OFDM subcarrier index, and N denotes the FFT size, wherein the B-S channel estimator approximates the channel estimation matrix by a matrix of the form or a matrix of the form where A and B and C are 2×2 matrices, if the error in such approximation is below an acceptable threshold.