Implementation and evaluation of channel estimation and phase tracking for vehicular networks

The high mobility of vehicular networks makes channel estimation and phase tracking challenging and an important problem for OFDM receiver design. In IEEE 802.11p vehicular networks, the channel estimation based on a long preamble in the PHY frame performs poorly in fast-fading channels. Moreover, the pilot-based phase tracking usually suffers from large residual phase errors. In this paper, we propose and implement a novel phase tracking algorithm, leveraging the decoded data. We also provide a detailed hardware design for a decoder-based channel estimation algorithm with a pipeline structure on an FPGA-based platform. Through diverse experiments via an advanced channel emulator, our results show that the proposed algorithm could significantly improve the system performance in terms of packet error rate, while adding less than 3% of additional hardware resources. We also jointly evaluate the packet error rate versus the bitwidth of the data in the FPGA, which is important to achieve a good balance between the hardware cost and the system performance.