OptiSystem 12.2 includes several important component and feature enhancements that improve the design and analysis capabilities of higher order modulation system designs (notably for 16-QAM and QPSK, single or dual polarization channel, coherent systems). New capabilities have been added to the DSP for 16-QAM component (formally known as DSP for DP-16-QAM) and DSP for QPSK component (formally known as DSP for DP-QPSK) including DC blocking, normalization, resampling, quadrature imbalance compensation, timing recovery & frequency offset estimation. Enhancements have also been made to the chromatic dispersion compensation, adaptive equalization, and carrier phase estimation algorithms. A new Decision component has been added to the Receivers/Demodulators library to allow for the automated setting and optimization of decision settings for QPSK and 16-QAM signal formats. Differential encoding has been added to the QPSK and QAM sequence generators and decoders (to resolve phase ambiguity problems with 16-QAM and QPSK modulation formats) thus providing improved distance performance for these types of coherent-based systems. The BER Test Set component has been enhanced to provide more effective measurement tools for the analysis of impairments in higher order modulation systems including bit error rate (BER) direct counts per sequence iteration and the running average of the BER results. Separate BER data is also provided for X, Y and X+Y polarization channels. The WDM Analyzer component has been updated to allow for the calculation of SNR or OSNR depending on the designer’s test configuration requirements. New “Symbol rate” and “Guard Bits” parameters have been added to the Global Parameters window to better align system settings for higher modulation systems.