DPSK and QAM modulation detectionanalyzed with BER estimation

Receiver can be used to detect modulation formats with QPSK, DPSK, 16QAM, 32QAM, 64QAM and 256QAM. To be able to identify clear performance tendencies for high-order modulation compared with formats are investigated formats by conducting comprehensive calculations in a uniform simulation atmosphere. The influence of different transmitter structures and decision schemes is measured and all systems are characterized with respect to the signal-to-noise ratio necessities, dispersal acceptance, and self-phase-modulation performance for non-return-to-zero (NRZ) and RZ pulse shapes. Moreover, an inherent problem of QAM transmission concerning SPM is presented, and advantage techniques are observed. The results give a significant insight into the properties of high-order modulation formats. The selection of modulation scheme depends on Bit Error Rate (BER), Signal to Noise Ratio (SNR), Available Bandwidth. The basic criteria for best modulation technique are Power efficiency, better Quality of Service, cost effectiveness, bandwidth efficiency and system complexity.