A unified architecture for efficient data and Non-Data Aided frequency estimation for FPGA implementation and application to satellite communications

Abstract

Modern codes such as Turbo and LDPC codes operate at low signal-to-noise ratios, which makes carrier synchronization a challenging problem. Hence in many waveforms, some known symbols are inserted periodically into the data stream to achieve Data-Aided (DA) synchronization. However, these known symbols decrease the throughput of the transmissions. The data symbols which are unknown can also be used for synchronization, in which case it is known as Non-Data Aided (NDA) synchronization. In this paper, we present an efficient structure which is almost the same for both the DA and NDA methods,especially suitable for implementation on Field Programmable Gate Arrays (FPGA). We discuss the implementation complexity and trade-offs involved in the FPGA implementation of this structure. We illustrate its utility by applying it a satellite communications waveform, popularly known as DVB-S2.