At the IEEE Globecom conference in Singapore from December 4 to 8, 2017, associate professor Yunlong Cai made relevant reports on the research of 5G millimeter-wave large-scale antenna mixed beam optimization algorithm and other aspects. Yunlong Cai has also made great progress in collaborations with the Department of Electrical Engineering of Georgia Institute of Technology, McGill university and the University of Southampton in fields of 5G waveform and access, 5G network resource optimization, multi-antenna wireless energy transmission and physical security. “Millimeter-wave transceiver based on antenna selection in MIMO system optimization algorithm" and " Wireless community more cost efficiency optimizationbased on the smart grid power ", were published in international communication and signal processing top journals, such as IEEE Trans. Commun, IEEE Trans. Signal Process, IEEE Trans. Wireless Commun, and IEEE j. Sel. Areas Commun. CAI was also selected as a senior member of IEEE, editor of IEEE Access, and Technical Committee member of Globecom, VTC and other top international communication conferences.
Part of the progress made is summarized as follows:
Firstly, a series of work has been carried out to optimize the design of transceiver in millimeter-wave antenna system. Considering the application in 5G network, the uplink link of large-scale multi-user MIMO millimeter-wave system is studied. In such a system, in order to reduce the huge energy consumption due to the simulation phase shifter and low noise amplifier, and to realize the complexity, hybrid receiver structure and antenna selection mechanism are adopted. Due to the antenna selection constraints and the constant mode constraints of the simulated receiving matrix, the corresponding optimization problems are non-convex and cannot be solved directly. By using the special structure of the problem and the principle of linear relaxation, we first transform the original problem into three sub-problems, and then use the alternative optimization method to solve it. For the antenna selection subproblem, we use the concave-convex procedure. The weighted minimum mean square variance (WMMSE) algorithm can be used to solve the problem of precoding to quantum. The final hybrid receiver problem is solved by manifold optimization principle. For the convergence of this algorithm, we give a detailed proof. In the simulation results, the proposed algorithm is higher in energy efficiency than the full digital precoding algorithm and the traditional OMP algorithm, while the complexity is also reduced. This work is published in the IEEE ICC 2017 and Top periodical IEEE j. Sel. Areas in Commun.
In addition, in multi-user MISO interference channel, we studied the design algorithm of transceiver based on information energy. In this system, signals received by the receiving end can be divided into two parts, one for information demodulation and the other for energy collection. Our goal is to minimize the total transmission energy of the system by combining the beam forming vector and the receiving power splitting factor in the receiver's SNR and energy collection constraints. In most articles considering such problems, it is assumed that the channel environment is ideal, but the channel error is unavoidable in the actual system. Therefore, we consider the robust transceiver design algorithm in the system and assume that the channel response satisfies the norm constraint error model. We propose three algorithms to solve this optimization problem. In the first algorithm, we propose a semi-positive relaxation technique to solve the original height non-convex problem, so that the original problem can be expressed as a semi-positive relaxation problem. It should be pointed out that the solution obtained through this algorithm is not necessarily a first-order matrix, and we also propose a first-order solution recovery algorithm. In the second algorithm, we propose a second-order cone programming relaxation techniques to simplify the algorithm design, and proposes a robust solution of closed recovery algorithm to deal with the resulting solution is not necessarily the robust. In the third algorithm, we propose an iterative algorithm based on matrix form, and prove that the algorithm can converge to the KKT solution of the original problem. Finally, the robustness and efficiency of the proposed algorithm are verified by simulation experiments. This work is published in the international Signal processing Top journal IEEE Trans. Signal Process.
This work obtained support and funding from the National Natural Science Foundation of China (project number: 61471319915810), the Natural Science Foundation of Zhejiang province, China (project number: LY14F010013), National Defense Scientific Research Fund, Zhejiang province key laboratory of information processing and communication network, the Department of Information and Communication Engineering, and Intelligent Communication Networks and Security Institute.
We are particularly grateful to Chaoyang Zhang, Minjian Zhao, Chunguang Li, Guanding Yu and Caijun Zhong and their teams for their enthusiastic help and guidance.
Part of the publications from 2016 to 2017:
1.Yunlong Cai, Zhijin Qin, Fangyu Cui, Geoffrey Ye Li, and Julie A. McCann, "Modulation and multiple access for 5G networks," IEEE Communications Survey and Tutorials, accepted for publication.
2.Lei Zhang, Yunlong Cai, Minjian Zhao, Benoit Champagne, and Lajos Hanzo, "Nonlinear MIMO transceivers improve wireless-powered and self-interference-aided relaying," IEEE Transactions on Wireless Communications, vol. 16, no. 10, pp. 6953-6966, Oct. 2017.
3.Ling Zhang, Yunlong Cai, Qingjiang Shi, Guanding Yu, Geoffrey Ye Li, "Cost efficiency optimization for multicell systems powered by smart grid," IEEE Transactions on Wireless Communications, vol. 16, no. 9, pp. 6047-6061, Sep. 2017.
4.Mingmin Zhao, Qingjiang Shi, Yunlong Cai and Minjian Zhao, "Joint transceiver design for full-duplex cloud radio access networks with SWIPT," IEEE Transactions on Wireless Communications, vol. 16, no. 9, pp. 5644-5658, Sep. 2017.
5.Yunlong Cai, Qingjiang Shi, Benoit Champagne, and Geoffrey Ye Li, "Joint transceiver design for secure downlink communications over an amplify-and-forward MIMO relay," IEEE Transactions on Communications, vol. 65, no. 9, pp. 3691-3704, Sep. 2017.
6.Xiongfei Zhai, Yunlong Cai, Qingjiang Shi, Minjian Zhao, Geoffrey Ye Li, and Benoit Champagne, "Joint transceiver design with antenna selection for large-scale MU-MIMO millimeter-wave systems," IEEE Journal on Selected Areas in Communications, Special Issue on Millimeter Wave Communications for Future Mobile Networks, vol. 35, no. 9, pp. 2085-2096, Sep. 2017.
7.Mingmin Zhao, Yunlong Cai, Qingjiang Shi, Mingyi Hong, and Benoit Champagne, "Joint transceiver designs for full-duplex K-pair MIMO interference channel with SWIPT," IEEE Transactions on Communications, vol. 65, no. 2, pp. 890-905, Feb. 2017.
8.Jiaxin Yang, Qiang Li, Yunlong Cai, Yulong Zou, Lajos Hanzo, and Benoit Champagne, "Joint secure AF relaying and artificial noise optimization: A penalized difference-of-convex programming framework, " IEEE Access, no. 4, pp. 10076-10095, 2016.
9.Qingjiang Shi, Mingyi Hong, Xiqi Gao, Enbin Song, Yunlong Cai, and Weiqiang Xu, "Joint source-relay design for full-duplex MIMO AF relay systems," IEEE Transactions on Signal Processing, vol. 64, no. 23, pp. 6118-6131, Dec. 1, 2016.
10.Ling Zhang, Yunlong Cai, Chunguang Li, and Rodrigo C. de Lamare, "Variable forgetting factor mechanisms for diffusion recursive least squares algorithms in sensor networks," EURASIP Journal on Advances in Signal Processing, accepted for publication.
11.Linzheng Qiu, Yunlong Cai, Rodrigo C. de Lamare, and Minjian Zhao, "Reduced-rank DOA estimation algorithms based on alternating low-rank decomposition," IEEE Signal Processing Letters, vol. 23, no. 5, pp. 565-569, May 2016.
12.Yunlong Cai, Mingmin Zhao, Qingjiang Shi, Benoit Champagne, and Minjian Zhao, "Joint transceiver design algorithms for multiuser MISO relay systems with energy harvesting," IEEE Transactions on Communications, vol. 64, no. 10, pp. 4147-4164, Oct. 2016.
13.Xiaomin Wu, Yunlong Cai, Rodrigo C. de Lamare, Benoit Champagne, and Minjian Zhao, "Adaptive widely-linear constrained constant modulus reduced-rank beamforming," IEEE Transactions on Aerospace and Electronic Systems, vol. 53, no. 1, pp. 477-492, Feb. 2017.
14.Mingmin Zhao, Yunlong Cai, Qingjiang Shi, Benoit Champagne, and Minjian Zhao, "Robust transceiver design for MISO interference channel with energy harvesting,"IEEE Transactions on Signal Processing, vol. 64, no. 17, pp. 4618-4633, Sep. 1, 2016.
15.Qingjiang Shi, Cheng Peng, Weiqiang Xu, Mingyi Hong, and Yunlong Cai, "Energy efficiency optimization for MISO SWIPT systems with zero-forcing beamforming,"IEEE Transactions on Signal Processing, vol. 64, no. 4, pp. 842-854, Feb. 15, 2016
