Rapid system prototyping for error-control coding in optical CDMA networks

With increasing bandwidth requirements of individual users, fibre-to-the-home systems are promising candidates for last mile communication. In case of local area networks, optical CDMA with nonorthogonal spreading sequences has emerged as an attractive technology that can manage quickly varying user requirements, while enabling total bandwidth utilization, avoiding network congestion and preventing denial of service. However, powerful error-control codes have to be utilized within optical CDMA systems to prevent errors caused by multiuser interference. Due to data rates common in optical communication, dedicated hardware is required to run such error-control codes at very high speeds, e.g., 155 Mbps or 652 Mbps.; This work presents a rapid system prototyping platform for error-control codes which are to be incorporated into the above mentioned optical CDMA systems. The platform consists of a design methodology, an extensive library of modules and an environment for testing designed specifically for optical CDMA systems but applicable to other communication systems as well. It is built on System Generator from Xilinx, a Matlab/Simulink based visual design tool, and enables a "push of a button" transition from code specification to real-time implementation on an FPGA chip.; Initially, both the hardware specifics of this platform and the details of the developed modular design methodology are presented. Consequently, implementation of a custom design construct (a Generate block) and a library of communication system modules are described together with blocks and methodology for testing the developed algorithms. Finally, design and evaluation of three different communication systems are presented. These designs show that the platform can be used for prototyping and evaluation of error-control algorithms running at the required processing speeds mentioned above.