In recent years, the Third Generation Partnership Project (3GPP) has developed the new radio-vehicle-to-everything (NR-V2X) sidelink standard, to enable direct communication between connected and autonomous vehicles (CAVs). Users can autonomously select radio resources for their transmissions with the Mode 2 channel access scheme, which can also operate under out-of-coverage conditions. However, Mode 2 performance is hindered by interference and packet collisions arising from dynamic mobile environments and limitations in assessing radio resource availability. The 3GPP specifications allow transmitting multiple copies of the same packet to improve reliability, though at the cost of increased channel congestion. This paper proposes to leverage receivers equipped with successive interference cancellation (SIC) capabilities, to exploit packet repetitions. Specifically, once a packet is successfully decoded the interfering contribution carried by repetitions can be cancelled from future or past received signals, enabling the decoding of new packets. Extensive highway scenario simulations demonstrate that the proposed solution significantly outperforms the legacy Mode 2 scheme, especially under high interference conditions, achieving improvements exceeding 100% in some cases.

翻译：近年来，第三代合作伙伴计划（3GPP）制定了新空口车联万物（NR-V2X）侧链路标准，以实现联网自动驾驶车辆间的直接通信。用户可通过模式2信道接入方案自主选择传输所需的无线资源，该模式亦可在网络覆盖范围外运行。然而，动态移动环境及无线资源可用性评估的局限性所引发的干扰与数据包碰撞，制约了模式2的性能表现。3GPP标准允许通过重复发送相同数据包副本以提升可靠性，但这会加剧信道拥塞。本文提出利用配备连续干扰消除（SIC）功能的接收机来处理数据包重复传输。具体而言，当数据包被成功解码后，其重复副本所携带的干扰分量可从未来或过去接收的信号中消除，从而实现对其他数据包的解码。大量高速公路场景仿真表明，所提方案显著优于传统模式2机制，尤其在高干扰环境下表现突出，部分场景中性能提升幅度超过100%。