Su, Xin, Shichao Yu, Jie Zeng, and Yujun Kuang. “Hierarchical Codebook Design for Massive MIMO”. EAI Endorsed Transactions on Scalable Information Systems 2, no. 4 (February 17, 2015): e5. Accessed November 22, 2024. https://publications.eai.eu/index.php/sis/article/view/2310.