A Survey on Radio Resource Allocation for V2X Communication

Table 4

Comparison of the existing overlaying resource allocation in V2X services.

Ref.	Unicast/broadcast	Objectives	Scenarios	User types	Allocation constraints	Allocation process	Methods/theory	RB sharing
[42]	Broadcast	Improve resource utilization efficiency	Highway	V-UEs	Reuse distance	Orthogonal resource is allocated to users whose relative distance is less than resource reuse distance	—	N V-UEs
[43]	—	—	Urban/freeway	Periodic traffic of V-UEs	—	Orthogonal RB are allocated for each user	—	1 V-UEs
[44]	Unicast	Minimize the total latency	Multilane highway	V2I-UEs	SINR	Orthogonal RBs are allocated to each V-UEs using D2D communication over C-V2X or 802.11p	Greedy algorithm	1 V2I-UE
[45]	Unicast	Improve network sum rate	Freeway	C-UEs; V-UEs	Fairness index; OP	Orthogonal RBs are allocated to C-UEs and V-UEs	Ant colony optimization mechanism	1 V-UE or 1 C-UE