Yunfei Chen, : 'Massive and network MIMO' (Telecommunications, 2017), 'Access, Fronthaul and Backhaul Networks for 5G & Beyond', Chap. 2, pp. 25-46, DOI: 10.1049/PBTE074E_ch2
IET Digital Library, https://digital-library.theiet.org/;jsessionid=3aww03atlmwe1.x-iet-live-01content/books/10.1049/pbte074e_ch2