Tentpoles Scheme: A Data-Aided Channel Estimation Mechanism for Achieving Reliable Vehicle-to-Vehicle Communications
IEEE 802.11p-based Dedicated Short Range Communications (DSRC) is considered a promising wireless technology for enhancing transportation safety and improving highway efficiency. One major challenge of IEEE 802.11p technology development ensuring its communication reliability in highly dynamic Vehicle-to-Vehicle (V2V) environments. In this paper, by investigating the characteristics of V2V channels through empirical measurements, we show that the decreased reliability of V2V communication is because the IEEE 802.11p design does not have sufficient number of training symbols in time domain and pilot subcarriers in frequency domain to enable estimation of the fast-changing V2V channels accurately. To tackle this challenge, we propose a new approach called Tentpoles scheme, which utilizes a small subset of data symbols and subcarriers protected by a strong Error Correction Code (ECC) to track and estimate V2V channel variations. Since this subset of data symbols and subcarriers provide dual-use, our Tentpoles scheme not only improves the accuracy of channel estimation and communication reliability, but has only a small impact on effective throughput. Through extensive simulations in synthetic V2V channels and emulation experiments using empirical measurements, our proposed Tentpoles scheme is shown to significantly outperform other V2V channel estimation and equalization methods in terms of communication reliability, at the cost of only moderate loss of throughput.