Communication Synchronization in Wireless Optical Link

Abstract

An FPGA based transceiving synchronization method is demonstrated for Free Space Optical (FSO) communication system, which is discussed separately as the transmitting protocol and the receiving protocol. During the discussion of these two parts, the co-operation of them is also discussed. The transmitting protocol interfaces the outer input data with a parallel port, buffers the input data, encodes the input data stream, serializes the parallel data and outputs the serialized data. It also has an output management unit to manage the activity of each part of the transmitting protocol. The receiving protocol filters and synchronizes the input serial data stream, parallels the serial data stream, decodes the input data, checks received error, handles transmission exception and interfaces the outer receiver with a parallel port. The entire transceiving protocol could be programmed into a single FPGA chip to improve system integrity and reduce the system cost. The presented protocol could be taken as "protocol transparent" for outer interfaces, meaning that when interfacing the presented system to an outer system, users don't have to consider what protocol the outer system transceiving data stream is under, for example, the TCP/IP protocol or anything else, in the case that its I/O interface is a parallel port. Simulation and final experiment prove that the protocol presented is a working solution at a certain bit rate scale.