Experimental Study of Capacity Approaching General LDPC Coded Non-Uniform Shaping Modulation Format

We experimentally demonstrate the efficiency of nonbinary GF(3)/GF(3 2 ) LPDC-coded non-uniform 9-QAM. We propose the non-uniform design method and low-complexity decoder. The proposed 9-QAM has >3dB gain in symbol OSNR compared to traditional binary LDPC-coded star-8-QAM.