1. Huang, P., Hao, Y., Lv, T., Xing, J., Yang, J., Mathiopoulos, P.T.: Secure beamforming design in relay-assisted Internet of Things. IEEE Internet Things J. 6(4), 6453–6464 (2019)
2. Yilmaz, E., Zakhour, R., Gesbert, D., Knopp, R.: Multi-pair two-way relay channel with multiple antenna relay station. In: Proceedings of the IEEE International Conference on Communications (ICC), pp. 1–5 (2010)
3. Farhadi, G., Beaulieu, N.C.: On the ergodic capacity of multi-hop wireless relaying systems. IEEE Trans. Commun. 8(5), 2286–2291 (2009)
4. Gu, Q., Wu, D., Su, X., Jin, J., Yuan, Y., Wang, J.: Performance comparison between reconfigurable intelligent surface and relays: theoretical methods and a perspective from operator (2021). Available via arXiv. https://arxiv.org/abs/2101.12091
5. Wu, Q., Zhang, R.: Towards smart and reconfigurable environment: Intelligent reflecting surface aided wireless network. IEEE Commun. 58(1), 106–112 (2020)