Topic 1:
Intelligent resource management and service provisioning for open radio access networks (O-RAN)
本研究專注在開放無線接取網路 (Open Radio Access Network, O-RAN) 與雲端接取網絡 (Could RAN, C-RAN) 架構下,提出一新穎之通訊服務模型,如圖所示,用以在密集小細胞網絡 (Dense Small Cell Network, DSN) 中提供高品質的通訊服務。為達成此目標,我們將頻譜資源共享、通道和功率分配以及干擾管理的跨層功能集成到 O-RAN/C-RAN 架構中,並藉由 DSN密集佈建的小基地台,提供可擴展且高效的寬頻無線通訊。所提出的方法和服務模型可以相容於支持 3GPP 標準的干擾控制機制,例如:feICIC/ICIC技術,具有作為DSN資源管理系統實作之可行性。根據大區域的模擬顯示,在跨越 100 平方公里的區域中,所提出的方法可以在單一電信營運商所擁有的 20 MHz頻譜資源下提供 21 Gbps 的下行通道吞吐量,相較典型 ICIC 方法的模擬結果,本研究提出的方法可以達到 5 倍的通訊增益,這顯示我們提出的方案對未來寬頻無線服務是一個頗具希望的高效益解決方案。相關論文發表如下:
S.-H. Wu, C.-H. Ko, and H.-L. Chao, “On-Demand Coordinated Spectrum and Resource Provisioning under an Open C-RAN Architecture for Dense Small Cell Networks,” early access on IEEE Trans. on Mobile Computing, Oct. 2022. (Link)
S. -H. Wu et al., “A cloud model and concept prototype for cognitive radio networks, ” in IEEE Wireless Communications, vol. 19, no. 4, pp. 49-58, August 2012. (Link)
S. -H. Wu, H. -L. Chao, C. -H. Ko, S. -R. Mo, C. -F. Liang and C. -C. Cheng, "Green Spectrum Sharing in a Cloud-Based Cognitive Radio Access Network," in 2013 IEEE International Conference on Green Computing and Communications and IEEE Internet of Things and IEEE Cyber, Physical and Social Computing, Beijing, China, 2013, pp. 276-281 (Link)
Topic 2:
mmWave hybrid beamforming and procoding for next generation mobile networks
本研究專注在寬頻毫米波多輸入與輸出系統(multiple input multiple output, MIMO)中,基於可重組式混合波束成型架構(reconfigurable hybrid beamforming, R-HBF)開發高效益的波束與通道追蹤機制。藉由可重組式混合波束成型架構的特性,我們以一種階層式的多重解析度波束掃描與空時壓縮感知技術,如圖所示,在毫米波MIMO 正交分頻多工系統(orthogonal frequency division multiplexing , OFDM)中達成快速波束與多通道係數的擷取與追蹤。模擬結果顯示我們所提出的方案大幅減低了波束訓練的時間,以估計的通道係數所得的通道容量相對於以完美通道係數所得的通道容量也僅只差 2dB。且既使在典型的都會毫米波行動通訊環境中,我們所提方案的波束選擇錯誤也僅約是0.001等級。相關論文發表如下:
S.-H. Wu and G.-Y. Lu, “Compressive Beam and Channel Tracking with Reconfigurable Hybrid Beamforming in mmWave MIMO OFDM Systems,” in IEEE Trans. on Wireless Communications, vol. 22, no. 2, pp. 1145-1160, Feb. 2023. (Link)
S.-H. Wu, L.-K. Chiu, and J.-W. Wang, "Reconfigurable hybrid beamforming for dual-polarized mmWave MIMO channels: Stochastic channel modeling and architectural adaptation methods,” in IEEE Trans. on Communications, vol. 66, no. 2, pp. 741-755, Feb. 2018. (Link)
S.-H. Wu, L.-K. Chiu, K.-Y. Lin and T.-H. Chang, "Robust hybrid beamforming with phased antenna arrays for downlink SDMA in indoor 60GHz channels,” in IEEE Trans. on Wireless Communications, vol. 12, no. 9, pp. 4542-4557, Sept. 2013. (Link)