A Survey: Nonorthogonal Multiple Access with Compressed Sensing Multiuser Detection for mMTC

Table 3

Comparison of medium access schemes.

Scheme	Signature	Frame structure	Medium access	Reference
Baseline nonorthogonal medium access	Node-specific sequence of the sensing matrix	Only data block	Direct access	[35–37]
Enhanced nonorthogonal medium access	Two sequences from the same sensing matrix	Only data block	Direct access	[43]
Multiple sequence-based nonorthogonal medium access	Frame ID		Random access	[38, 39]
Codebook-based nonorthogonal medium access	Codebook	Only data block	Direct access	[53]
Channel division random access	Channel state information		Random access	[41, 42]