Synchronization of high speed OFDM links using variations of Schmidl Cox for SNR improvement

摘要

Owing to the growing demand for the high-speed wireless communications which uses Orthogonal Frequency Division Multiplexing (OFDM), there is a need to provide high-quality to overcome various channel impairments appearing over the transmission link. One of the main problems in providing such mechanisms is Doppler shift. which reduces the spectral efficiency of the system, raising a need to determine its value with high accuracy. In order to estimate this frequency shift, first the timing recovery is required. Over the years, Schmidl Cox algorithm has been used to determine this Doppler shift with considerate amount of success. But, with the increasing speed of the vehicle and the worsening channel conditions, this algorithm succumb to failure. The paper discusses the limitations of basic Schmidl Cox algorithm and the necessary improvements to be made, so as to push them to work better at harder conditions too.