All digital time tracking loop for DVB-H and DVB-T

Wireless OFDM receivers are subject to sample timing errors, causing both sample period and phase errors. Frequency errors lead to loss of orthogonality between subcarriers, resulting in inter-carrier interference (ICI). On the other hand, phase errors lead to erroneous interpretation of the symbols, which degrades the system performance by increasing the BER. In this paper, a time tracking loop is proposed for OFDM based broadcast systems. The proposed time tracking topology is a fast digital feed-back loop which corrects the timing errors for OFDM based broadcast systems, such as DVB-H and DVB-T, efficiently. The loop is implemented with Verilog code targeting the Xilinx Virtex2 xc2v8000 FPGA and it gives effective signal to error ratio 35dB.