Experimental Performance of 4D Optimized Constellation Alternatives for PM-8QAM and PM-16QAM
09 March 2014
Sensitivity of soft-decoded PM-8QAM was improved by 1.1-dB by moving to a new 64 point 4D constellation and to a tailored LDPC code. Replacing coded PM-16QAM by a 256 point constellation lead to 0.6-dB sensitivity gain.
