Prerequisites & Notation
Before You Begin
This chapter applies the OTFS machinery developed in Chapters 9-14 to vehicular networks — the single most demanding application domain for high-mobility communications. V2X combines the extremes of wireless: 300 km/h closure speeds, sub-millisecond latency targets, cm-level positioning accuracy, and a rich regulatory overlay. OTFS's delay-Doppler foundation addresses each of these constraints directly. This section lays out what the reader should remember from previous chapters and what broader context is helpful.
- OTFS performance analysis and diversity(Review OTFS Ch. 9)
Self-check: Can you state OTFS's delay-Doppler diversity and the gain over OFDM in high-mobility?
- OTFS-ISAC fundamentals and joint estimation(Review OTFS Ch. 12)
Self-check: Do you recall the joint estimation-detection algorithm?
- MIMO-OTFS-ISAC beamforming(Review OTFS Ch. 13)
Self-check: Can you formulate the joint beamforming SDP?
- Sensing-assisted communication(Review OTFS Ch. 14)
Self-check: Can you derive the SAC pilot-overhead savings formula?
- Cellular network architecture(Review Telecom Ch. 15, Ch. 16)
Self-check: Are you familiar with basic 5G architecture (gNB, UE, core network)?
Notation for This Chapter
V2X-specific symbols introduced in this chapter.
| Symbol | Meaning | Introduced |
|---|---|---|
| Relative velocity between two vehicles (for V2V) | s02 | |
| V2V Doppler spread: up to due to bidirectional motion | s02 | |
| Set of vehicles in a cooperative platoon | s05 | |
| Safety-critical latency budget: 1 ms (platooning), 10 ms (ICS) | s05 | |
| Inter-vehicle distance (platoon spacing) | s05 | |
| V2X data rate (typically 10-100 Mbps uncoded) | s01 |