A double decoding scheme to improve the PER performance of V2V communications

In this paper, we investigate to achieve low Packet Error Rate (PER) for Vehicle-to-Vehicle (V2V) communications within the IEEE 802.11p standard. We first present the best achievable PER with the assumption of perfect channel knowledge. Then we propose to approach the best achievable PER with a relaxed assumption of partial channel knowledge, i.e., knowing a few separated channels in a packet. In order to obtain partial channel knowledge in an 802.11p standard-compliant way, we propose a sub-packet decoding processing in which the successful decoding of the previous sub-packet will provide partial channel knowledge for decoding the following sub-packet. Then we design a double decoding scheme to achieve low PER in a standard-compliant way. The double decoding scheme utilizes the error detection information provided by CRC check in medium-access (MAC) layer and combines two different decoding methods in physical (PHY) layer. The results show that comparing to previous work, the proposed double decoding can improve PER significantly.