Cell-Free Cooperative Non-Orthogonal Multiple Access for 6G Wireless Systems

The diversified opportunities and challenges in various sectors necessitate development of sixth-generation (6G) wireless systems with extremely high data rate, massive connectivity, minimal latency, good coverage, high reliability, optimal resource allocation, good spectral and energy efficiency. Multiple access is a key technique in the wireless technological evolution that provides access to multiple users with the available resources. Even though 5G system promises data rate in Gbps and latency below 1 ms with a wide bandwidth ranges from 30 GHz to 300 GHZ, its range of coverage was limited. Hence, the infrastructure needs to be rebuilt to overcome the limitation. NOMA is the key enabler for bringing down the interference effects and sharing the spectrum among multiple users in an efficient way. Cooperative communication is another promising technology that can improve coverage and capacity of the wireless system. Cell free communication with cooperative NOMA architecture is proposed in this chapter to meet 6G requirements at THz band.