This book provides a comprehensive exploration of Non-Orthogonal Multiple Access (NOMA) in Heterogeneous Cellular Networks (HCNs), focusing on both theoretical foundations and practical considerations. It examines critical challenges such as non-linear high-power amplifiers (HPAs), and imperfections in successive interference cancellation (SIC). Furthermore, it presents advanced techniques including simultaneous wireless information and power transfer (SWIPT) with cooperative NOMA and the ...