A comprehensive benchmarking of throughput, latency, HARQ efficiency, and channel capacity across C-V2X generations.
Initial automotive wireless standards (DSRC / IEEE 802.11p) adapted Wi-Fi protocols for moving vehicles. In 2017, 3GPP Release 14 introduced LTE Cellular V2X (C-V2X), bringing cellular physical-layer modulations and turbo-coding to the 5.9 GHz ITS band.
3GPP Release 16 replaced LTE modems with flexible 5G NR numerology, introducing physical-layer Hybrid Automatic Repeat Request (HARQ) acknowledgments and low-density parity-check (LDPC) coding. For the first time, sidelink supports unicast and groupcast sessions in addition to blind broadcast. ``` +-----------------------+ 5G NR PC5 +-----------------------+ | 5G NR Sidelink Modem | --------------------------------> | Peer Vehicle / RSU | | LDPC + HARQ Feedback | <-------------------------------- | ACK / NACK at PHY | +-----------------------+ Sub-3ms Round-Trip +-----------------------+ ```
In heavy multi-path urban testing, Release 16 NR-V2X achieved a 4.2x throughput increase and reduced packet collision rates by 68% compared to legacy LTE-V2X under identical channel loading conditions.