Enabling Device-to-Device Transmission for NOMA-Aided Systems

Table 1

A comparison of existing works on NOMA-aided D2D networks with imperfect CSI.

Scheme	Reference	Major contributions
FD-SWIPT NOMA-D2D	[31]	The authors derived ergodic capacity expressions and closed form OP with imperfect CSI conditions.
SWIPT NOMA-D2D	[32]	The authors studied the resource allocation problem by modeling the problem as a nonconvex optimization problem where the transmit power, power splitting factor, and resource block assignment factor are jointly designed to obtain the maximum OP of each D2D user, the SIC decoding order, and the maximum transmit power of the base station and D2D users.
Secure FD-SWIPT NOMA-D2D	[33]	The authors studied the system total transmit power minimization and formulated a multiobjective optimization (MOO) problem utilizing the weighted Tchebycheff method.
NOMA-D2D	[34]	The authors considered two-stage power allocation in maximizing the system sum rate of a cooperative NOMA-aided D2D system operating with imperfect CSI at the base station.
NOMA-D2D	[35]	The authors proposed a power allocation algorithm for D2D-assisted cooperative NOMA networks under imperfect CSI.
Fog computing NOMA-D2D	[36]	The authors considered the integration of NOMA-aided D2D communication with fog computing (FC) under imperfect CSI and utilized coalition game theory to enhance spectral efficiency and secrecy capacity.
mmWave NOMA-D2D	[37]	The authors considered mmWave NOMA-aided D2D systems under transceiver hardware and CSI impairments. The authors derived generalized OP expressions and confirmed via simulation results that their proposed system outperforms OMA.
NOMA-D2D	Our work	We consider transmission assisted by NOMA where a single antenna base station communicates with two groups of D2D users arranged in a radial manner around the base station. Then, based on the stochastic geometry approach, we investigate the impact of channel estimation error on OP and throughput of the proposed system. Simulations show that our proposed system still enhances spectral efficiency despite imperfect channel estimation and throughput limitations.