Performance Study of Three (3) Digital Modulations Using New D-PISO Architecture In FPGA

Dynamic symbol size modulation is a type modulation which could provide a fast transmission speed by removing the redundant symbol as compared to fixed symbol size modulation. The dynamic nature of the symbol created an additional problem in hardware design as the size of the symbol needed to be defined clearly and it cannot be changed and altered once the design has been generated. Thus, to address the issue, this research investigated the best implementation method and performance study of fixed and dynamic symbol size digital baseband modulation for an optical communication system in FPGA hardware design. KCU105 FPGA development board and Vivado software were chosen as the main platform to implement the design. A new Dynamic-Parallel Input Serial Output (D-PISO) architecture to implement dynamic symbol size baseband modulation in FPGA is created. Next, by using D-PISO architecture, dynamic symbol size modulation namely 8-reverse dual header pulse interval modulation (8-RDHPIM), 8-digital pulse interval modulation (8-DPIM) and fixed symbol size modulation 8-pulse position modulation (8-PPM) were fully implemented in the FPGA which has a transmitter and receiver module. An experimental comparative study was then carried out for each modulation technique. The main parameters investigated were symbol error rate performances. From the results, it can be concluded that for a power-limited system, 8-PPM could be selected as it can maintain a small number of symbol error rate (SER) even during low power transmission which is around -6 dBm. On the other hand, the 8-DPIM and 8-RDHPIM that achieved the transmission speed of 33.3 Mbps and 27.27 Mbps are suitable for systems that require high data speed and minimal clock synchronization.