Abstract
A simultaneously transmitting and reflecting reconfigurable intelligent surface (STAR-RIS) assisted multiuser near-field wideband communication system is investigated, in which a robust deep reinforcement learning (DRL) based algorithm is proposed to enhance the users’ achievable rate by jointly optimizing the active beamforming at the base station (BS) and passive beamforming at the STAR-RIS. To mitigate the beam split issue, the delay-phase hybrid precoding structure is introduced to facilitate wideband beamforming. Considering the coupled nature of the STAR-RIS phase-shift model, the passive beamforming design is formulated as a problem of hybrid continuous and discrete phase-shift control, and the proposed algorithm controls the high-dimensional continuous action through hybrid action mapping. Additionally, to address the issue of biased estimation encountered by existing DRL algorithms, a softmax operator is introduced into the algorithm to mitigate this bias. Simulation results illustrate that the proposed algorithm outperforms existing algorithms and overcomes the issues of overestimation and underestimation.
摘要
本文研究了一种智能全向超表面辅助的多用户近场宽带通信系统, 提出了一种基于深度强化学习的鲁棒算法。通过联合优化基站的主动波束成形和智能全向超表面的被动波束成形, 提升用户的可达速率。为缓解宽带通信中的波束分裂问题, 引入了时相联合的混合预编码结构, 以实现高效的宽带波束成形。考虑到智能全向超表面相移模型的耦合性, 将无源波束成形设计转化为连续与离散相移的混合控制问题, 并通过混合动作映射解决高维连续动作的控制难题。此外, 针对现有深度强化学习算法中的估计偏差问题, 引入softmax算子有效减轻了该偏差。仿真结果表明, 所提算法在克服估计过高和估计过低问题方面优于现有算法。
Data availability
The data that support the findings of this study are available from the corresponding author upon reasonable request.
References
Abeywickrama S, Zhang R, Wu QQ, et al., 2020. Intelligent reflecting surface: practical phase shift model and beamforming optimization. IEEE Trans Commun, 68(9):5849–5863. https://doi.org/10.1109/TCOMM.2020.3001125
Dai LL, Tan JB, Chen Z, et al., 2022. Delay-phase precoding for wideband THz massive MIMO. IEEE Trans Wirel Commun, 21(9):7271–7286. https://doi.org/10.1109/TWC.2022.3157315
ElMossallamy MA, Zhang HL, Song LY, et al., 2020. Reconfigurable intelligent surfaces for wireless communications: principles, challenges, and opportunities. IEEE Trans Cogn Commun Netw, 6(3):990–1002. https://doi.org/10.1109/TCCN.2020.2992604
Fujimoto S, van Hoof H, Meger D, 2018. Addressing function approximation error in actor-critic methods. https://arxiv.org/abs/1802.09477
Gao XY, Dai LL, Zhou SD, et al., 2019. Wideband beamspace channel estimation for millimeter-wave MIMO systems relying on lens antenna arrays. IEEE Trans Signal Process, 67(18):4809–4824. https://doi.org/10.1109/TSP.2019.2931202
Guo KF, Liu R, Alazab M, et al., 2023. STAR-RIS-empowered cognitive non-terrestrial vehicle network with NOMA. IEEE Trans Intell Veh, 8(6):3735–3749. https://doi.org/10.1109/TIV.2023.3264212
Han C, Akyildiz IF, 2016. Distance-aware bandwidth-adaptive resource allocation for wireless systems in the terahertz band. IEEE Trans Terahertz Sci Technol, 6(4):541–553. https://doi.org/10.1109/TTHZ.2016.2569460
Han C, Yan LF, Yuan JH, 2021. Hybrid beamforming for terahertz wireless communications: challenges, architectures, and open problems. IEEE Wirel Commun, 28(4):198–204. https://doi.org/10.1109/MWC.001.2000458
He XL, Xu HB, Wang J, et al., 2024. Joint active and passive beamforming in RIS-assisted covert symbiotic radio based on deep unfolding. IEEE Trans Veh Technol, 73(9):14021–14026. https://doi.org/10.1109/TVT.2024.3393724
Headland D, Monnai Y, Abbott D, et al., 2018. Tutorial: terahertz beamforming, from concepts to realizations. APL Photon, 3(5):051101. https://doi.org/10.1063/1.5011063
Hua M, Wu QQ, Chen W, et al., 2024a. Intelligent reflecting surface assisted localization: performance analysis and algorithm design. IEEE Wirel Commun Lett, 13(1):84–88. https://doi.org/10.1109/LWC.2023.3320728
Hua M, Wu QQ, Chen W, et al., 2024b. Secure intelligent reflecting surface-aided integrated sensing and communication. IEEE Trans Wirel Commun, 23(1):575–591. https://doi.org/10.1109/TWC.2023.3280179
Huang CW, Alexandropoulos GC, Zappone A, et al., 2019. Deep learning for UL/DL channel calibration in generic massive MIMO systems. Proc IEEE Int Conf on Communications, p.1–6. https://doi.org/10.1109/ICC.2019.8761962
Huang CW, Mo RH, Yuen C, 2020. Reconfigurable intelligent surface assisted multiuser MISO systems exploiting deep reinforcement learning. IEEE J Select Areas Commun, 38(8):1839–1850. https://doi.org/10.1109/JSAC.2020.3000835
Jiang CX, Zhang HJ, Ren Y, et al., 2017. Machine learning paradigms for next-generation wireless networks. IEEE Wirel Commun, 24(2):98–105. https://doi.org/10.1109/MWC.2016.1500356WC
Kraus JD, Marhefka RJ, 2002. Antennas for All Applications (3rd Ed.). McGraw-Hill Science/Engineering/Math, New York, USA.
Li HC, Liu YW, Mu XD, et al., 2023. Near-field beamforming for STAR-RIS networks. https://arxiv.org/abs/2306.14587
Li HY, Li M, Liu Q, et al., 2020. Dynamic hybrid beam-forming with low-resolution PSs for wideband mmWave MIMO-OFDM systems. IEEE J Sel Areas Commun, 38(9):2168–2181. https://doi.org/10.1109/JSAC.2020.3000878
Li XW, Xie Z, Chu Z, et al., 2022. Exploiting benefits of IRS in wireless powered NOMA networks. IEEE Trans Green Commun Netw, 6(1):175–186. https://doi.org/10.1109/TGCN.2022.3144744
Li XW, Zhang JY, Han CZ, et al., 2024. Reliability and security of CR-STAR-RIS-NOMA-assisted IoT networks. IEEE Int Things J, 11(17):27969–27980. https://doi.org/10.1109/JIOT.2023.3340371
Liu R, Guo KF, Li XW, et al., 2024. RIS-empowered satellite-aerial-terrestrial networks with PD-NOMA. IEEE Commun Surv Tutor, 26(4):2258–2289. https://doi.org/10.1109/COMST.2024.3393612
Mismar FB, Evans BL, Alkhateeb A, 2020. Deep reinforcement learning for 5G networks: joint beamforming, power control, and interference coordination. IEEE Trans Commun, 68(3):1581–1592. https://doi.org/10.1109/TCOMM.2019.2961332
Mnih V, Kavukcuoglu K, Silver D, et al., 2015. Human-level control through deep reinforcement learning. Nature, 518(7540):529–533. https://doi.org/10.1038/nature14236
Mu XD, Liu YW, Guo L, et al., 2020. Exploiting intelligent reflecting surfaces in NOMA networks: joint beam-forming optimization. IEEE Trans Wirel Commun, 19(10):6884–6898. https://doi.org/10.1109/TWC.2020.3006915
Mu XD, Liu YW, Guo L, et al., 2022. Simultaneously transmitting and reflecting (STAR) RIS aided wireless communications. IEEE Trans Wirel Commun, 21(5):3083–3098. https://doi.org/10.1109/TWC.2021.3118225
Ni WL, Liu YW, Eldar YC, et al., 2021. STAR-RIS enabled heterogeneous networks: ubiquitous NOMA communication and pervasive federated learning. https://arxiv.org/abs/2106.08592v1
Pan L, Cai Q, Huang L, 2020. Softmax deep double deterministic policy gradients. Proc 34th Int Conf on Neural Information Processing Systems, p.11767–11777.
Samir M, Elhattab M, Assi C, et al., 2021. Optimizing age of information through aerial reconfigurable intelligent surfaces: a deep reinforcement learning approach. IEEE Trans Veh Technol, 70(4):3978–3983. https://doi.org/10.1109/TVT.2021.3063953
Shafin R, Chen H, Nam YH, et al., 2020. Self-tuning sectorization: deep reinforcement learning meets broadcast beam optimization. IEEE Trans Wirel Commun, 19(6):4038–4053. https://doi.org/10.1109/TWC.2020.2979446
Silver D, Lever G, Heess N, et al., 2014. Deterministic policy gradient algorithms. Proc 31st Int Conf on Machine Learning, p.I-387–I-395.
Wang J, Xiao J, Zou YX, et al., 2024. Wideband beamforming for RIS assisted near-field communications. IEEE Trans Wirel Commun, 23(11):16836–16851. https://doi.org/10.1109/TWC.2024.3447570
Wang ZL, Mu XD, Xu JQ, et al., 2023. Simultaneously transmitting and reflecting surface (STARS) for terahertz communications. IEEE J Sel Top Signal Process, 17(4):861–877. https://doi.org/10.1109/JSTSP.2023.3279621
Wu CY, Liu YW, Mu XD, et al., 2021. Coverage characterization of STAR-RIS networks: NOMA and OMA. IEEE Commun Lett, 25(9):3036–3040. https://doi.org/10.1109/LCOMM.2021.3091807
Xiao J, Wang J, Wang ZL, et al., 2024a. Multi-scale attention based channel estimation for RIS-aided massive MIMO systems. IEEE Trans Wirel Commun, 23(6):5969–5984. https://doi.org/10.1109/TWC.2023.3329387
Xiao J, Wang J, Wang ZL, et al., 2024b. Multi-task learning for near/far field channel estimation in STAR-RIS networks. IEEE Trans Commun, 72(10):6344–6359. https://doi.org/10.1109/TCOMM.2024.3402619
Xu C, Ishikawa N, Rajashekar R, et al., 2019. Sixty years of coherent versus non-coherent tradeoffs and the road from 5G to wireless futures. IEEE Access, 7:178246–178299. https://doi.org/10.1109/ACCESS.2019.2957706
Yu XH, Shen JC, Zhang J, et al., 2016. Alternating minimization algorithms for hybrid precoding in millimeter wave MIMO systems. IEEE J Sel Top Signal Process, 10(3):485–500. https://doi.org/10.1109/JSTSP.2016.2523903
Zhang E, Huang C, 2014. On achieving optimal rate of digital precoder by RF-baseband codesign for MIMO systems. Proc IEEE 80th Vehicular Technology Conf, p.1–5. https://doi.org/10.1109/VTCFall.2014.6966076
Zhou Y, Zhou FH, Wu YP, et al., 2020. Subcarrier assignment schemes based on Q-learning in wideband cognitive radio networks. IEEE Trans Veh Technol, 69(1):1168–1172. https://doi.org/10.1109/TVT.2019.2953809
Zhu BO, Chen K, Jia N, et al., 2014. Dynamic control of electromagnetic wave propagation with the equivalent principle inspired tunable metasurface. Sci Rep, 4(1):4971. https://doi.org/10.1038/srep04971
Zhu FH, Wang BH, Yang ZH, et al., 2023. Robust millimeter beamforming via self-supervised hybrid deep learning. Proc 31st European Signal Processing Conf, p.915–919. https://doi.org/10.23919/eusipco58844.2023.10289989
Zhu FH, Wang XQ, Huang CW, et al., 2024. Beamforming inferring by conditional WGAN-GP for holographic antenna arrays. IEEE Wirel Commun Lett, 13(7):2023–2027. https://doi.org/10.1109/LWC.2024.3402102
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Contributions
Ji WANG designed the research. Jiayi SUN and Wei FANG processed the data. Ji WANG and Jiayi SUN drafted the paper. Zhao CHEN helped organize the paper. Zhao CHEN, Yue LIU, and Yuanwei LIU revised and finalized the paper.
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Yuanwei LIU is a guest editor of this special issue, and he was not involved with the peer review process of this paper. All the authors declare that they have no conflict of interest.
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Project supported by the National Natural Science Foundation of China (Nos. 62101205 and 62101308) and the Key Research and Development Program of Hubei Province, China (No. 2023BAB061)
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Wang, J., Sun, J., Fang, W. et al. Deep reinforcement learning for near-field wideband beamforming in STAR-RIS networks. Front Inform Technol Electron Eng 25, 1651–1663 (2024). https://doi.org/10.1631/FITEE.2400364
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DOI: https://doi.org/10.1631/FITEE.2400364
Key words
- Deep reinforcement learning
- Near-field beamforming
- Simultaneously transmitting and reflecting reconfigurable intelligent surface (STAR-RIS)
- Wideband beam split