On the Uplink Distributed Detection in UAV-enabled Aerial Cell-Free mMIMO Systems (2307.06023v1)
Abstract: In this paper, we investigate the uplink signal detection approaches in the cell-free massive MIMO systems with unmanned aerial vehicles (UAVs) serving as aerial access points (APs). The ground users are equipped with multiple antennas and the ground-to-air propagation channels are subject to correlated Rician fading. To overcome huge signaling overhead in the fully-centralized detection, we propose a two-layer distributed uplink detection scheme, where the uplink signals are first detected in the AP-UAVs by using the minimum mean-squared error (MMSE) detector depending on local channel state information (CSI), and then collected and weighted combined at the CPU-UAV to obtain the refined detection. By using the operator-valued free probability theory, the asymptotic expressions of the combining weights are obtained, which only depend on the statistical CSI and show excellent accuracy. Based on the proposed distributed scheme, we further investigate the impacts of different distributed deployments on the achieved spectral efficiency (SE). Numerical results show that in urban and dense urban environments, it is more beneficial to deploy more AP-UAVs to achieve higher SE. On the other hand, in suburban environment, an optimal ratio between the number of deployed UAVs and the number of antennas per UAV exists to maximize the SE.
- M. Mozaffari, X. Lin, and S. Hayes, “Toward 6g with connected sky: Uavs and beyond,” IEEE Commun. Mag., vol. 59, no. 12, pp. 74–80, 2021.
- G. Geraci, A. Garcia-Rodriguez, M. M. Azari, A. Lozano, M. Mezzavilla, S. Chatzinotas, Y. Chen, S. Rangan, and M. Di Renzo, “What will the future of uav cellular communications be? a flight from 5g to 6g,” IEEE Commun. Surveys Tuts., vol. 24, no. 3, pp. 1304–1335, 2022.
- H. Q. Ngo, A. Ashikhmin, H. Yang, E. G. Larsson, and T. L. Marzetta, “Cell-free massive mimo versus small cells,” IEEE Trans. Wireless Commun., vol. 16, no. 3, pp. 1834–1850, 2017.
- E. Björnson and L. Sanguinetti, “Scalable cell-free massive mimo systems,” IEEE Trans. Commun., vol. 68, no. 7, pp. 4247–4261, 2020.
- E. Nayebi, A. Ashikhmin, T. L. Marzetta, H. Yang, and B. D. Rao, “Precoding and power optimization in cell-free massive mimo systems,” IEEE Trans. Wireless Commun., vol. 16, no. 7, pp. 4445–4459, 2017.
- J. Zheng, J. Zhang, and B. Ai, “Uav communications with wpt-aided cell-free massive mimo systems,” IEEE J. Sel. Areas Commun., vol. 39, no. 10, pp. 3114–3128, 2021.
- C. D’Andrea, A. Garcia-Rodriguez, G. Geraci, L. G. Giordano, and S. Buzzi, “Cell-free massive mimo for uav communications,” in IEEE Int. Conf. Commun. Workshops (ICC Workshops), May 2019, pp. 1–6.
- C. Diaz-Vilor, A. Lozano, and H. Jafarkhani, “Cell-free uav networks: Asymptotic analysis and deployment optimization,” IEEE Trans. Wireless Commun., 2022.
- L. Wang and Q. Zhang, “Cell-free massive mimo with uav access points: Uav location optimization,” in Proc. 2022 IEEE/CIC Int. Conf. Commun. China (ICCC), Aug. 2022, pp. 262–267.
- C. Diaz-Vilor, A. Lozano, and H. Jafarkhani, “On the deployment problem in cell-free uav networks,” in Proc. IEEE Global Commun. Conf. (GLOBECOM), Dec. 2021, pp. 1–6.
- J. Zhang, R. Chen, J. G. Andrews, A. Ghosh, and R. W. Heath, “Networked mimo with clustered linear precoding,” IEEE Trans. Wireless Commun., vol. 8, no. 4, pp. 1910–1921, 2009.
- E. Bjornson, N. Jalden, M. Bengtsson, and B. Ottersten, “Optimality properties, distributed strategies, and measurement-based evaluation of coordinated multicell ofdma transmission,” IEEE Trans. Signal Process., vol. 59, no. 12, pp. 6086–6101, 2011.
- I. D. Garcia, N. Kusashima, K. Sakaguchi, and K. Araki, “Dynamic cooperation set clustering on base station cooperation cellular networks,” in Proc. 21st Annu. IEEE Int. Symp. Pers., Indoor Mobile Radio Commun., Sep. 2010, pp. 2127–2132.
- A. Adhikary, A. Ashikhmin, and T. L. Marzetta, “Uplink interference reduction in large-scale antenna systems,” IEEE Trans. Commun., vol. 65, no. 5, pp. 2194–2206, 2017.
- E. Björnson and L. Sanguinetti, “Making cell-free massive mimo competitive with mmse processing and centralized implementation,” IEEE Trans. Wireless Commun., vol. 19, no. 1, pp. 77–90, 2019.
- E. Nayebi, A. Ashikhmin, T. L. Marzetta, and B. D. Rao, “Performance of cell-free massive mimo systems with mmse and lsfd receivers,” in Proc. 50th Asilomar Conf. Signals, Syst. Comput., Nov. 2016, pp. 203–207.
- J. Zhang, J. Zhang, E. Björnson, and B. Ai, “Local partial zero-forcing combining for cell-free massive mimo systems,” IEEE Trans. Commun., vol. 69, no. 12, pp. 8459–8473, 2021.
- T. C. Mai, H. Q. Ngo, and T. Q. Duong, “Uplink spectral efficiency of cell-free massive mimo with multi-antenna users,” in Proc. 3rd Int. Conf. Recent Adv. Signal Process., Telecommun. Comput. (SigTelCom), Mar. 2019, pp. 126–129.
- ——, “Downlink spectral efficiency of cell-free massive mimo systems with multi-antenna users,” IEEE Trans. Commun., vol. 68, no. 8, pp. 4803–4815, 2020.
- Z. Wang, J. Zhang, B. Ai, C. Yuen, and M. Debbah, “Uplink performance of cell-free massive mimo with multi-antenna users over jointly-correlated rayleigh fading channels,” IEEE Trans. Wireless Commun., vol. 21, no. 9, pp. 7391–7406, 2022.
- Z. Wang, J. Zhang, H. Q. Ngo, B. Ai, and M. Debbah, “Iteratively weighted mmse uplink precoding for cell-free massive mimo,” in Proc. IEEE Int. Conf. Commun. (ICC), May 2022, pp. 231–236.
- M. Alzenad, A. El-Keyi, F. Lagum, and H. Yanikomeroglu, “3-d placement of an unmanned aerial vehicle base station (uav-bs) for energy-efficient maximal coverage,” IEEE Wireless Commun. Lett., vol. 6, no. 4, pp. 434–437, 2017.
- K. Yu and B. Ottersten, “Models for mimo propagation channels: a review,” Wireless Commun. Mobile Comput., vol. 2, no. 7, pp. 653–666, 2002.
- J. Zhang, C.-K. Wen, S. Jin, X. Gao, and K.-K. Wong, “On capacity of large-scale mimo multiple access channels with distributed sets of correlated antennas,” IEEE J. Sel. Areas Commun., vol. 31, no. 2, pp. 133–148, 2013.
- E. Bjornson and B. Ottersten, “A framework for training-based estimation in arbitrarily correlated rician mimo channels with rician disturbance,” IEEE Trans. Signal Process., vol. 58, no. 3, pp. 1807–1820, 2009.
- X. Li, E. Björnson, S. Zhou, and J. Wang, “Massive mimo with multi-antenna users: When are additional user antennas beneficial?” in Proc. 23rd Int. Conf. Telecommun. (ICT), May 2016, pp. 1–6.
- X. Pan, Z. Zheng, Z. Fei, and Z. Zhang, “On the design of optimal one-shot distributed combining for cooperative multi-uav systems,” IEEE Trans. Veh. Technol., vol. 72, no. 5, pp. 6827–6832, 2023.
- A.-A. Lu, X. Gao, and C. Xiao, “Free deterministic equivalents for the analysis of mimo multiple access channel,” IEEE Trans. Inf. Theory, vol. 62, no. 8, pp. 4604–4629, 2016.
- S. T. Belinschi, T. Mai, and R. Speicher, “Analytic subordination theory of operator-valued free additive convolution and the solution of a general random matrix problem,” J. Reine Angew. Math. (Crelles J.), vol. 2017, no. 732, pp. 21–53, 2017.
- D. Voiculescu, “Operations on certain non-commutative operator-valued random variables,” Astérisque, vol. 232, no. 1, pp. 243–275, 1995.
- E. Dobriban and Y. Sheng, “Wonder: weighted one-shot distributed ridge regression in high dimensions,” J. Mach. Learn. Res., vol. 21, no. 1, pp. 2483–2534, 2020.
- A. Al-Hourani, S. Kandeepan, and S. Lardner, “Optimal lap altitude for maximum coverage,” IEEE Wireless Commun. Lett., vol. 3, no. 6, pp. 569–572, 2014.