Science China Information Sciences

, Volume 59, Issue 2, pp 1–8

# Energy efficient design for multiuser downlink energy and uplink information transfer in 5G

• Chunguo Li
• Yanshan Li
• Kang Song
• Luxi Yang
Research Paper Special Focus on 5G Wireless Communication Networks

## Abstract

Simultaneous wireless information and power transfer (SWIPT) is studied in this paper for the wireless powered downlink (DL) and multiuser information uplink (UL) systems. The objective is to maximize the energy efficiency defined as the ratio of the achieved throughput over the energy cost by optimizing the time allocation for the DL and multi-user UL traffics and its goal is to obtain the analytical expression to the optimal time allocation yet the resulting difficulty comes from the sum throughput of the multiuser in UL as well as the corresponding power consumption. To tackle this, the Jensen inequality is applied to approximating the exact expression of the sum throughput for the UL multi-users, leading to an upper-bound of the counterpart. The final closed form is exact in the single-user scenario yet approximate in the multi-user scenario. Numerical simulations verify the tightness of this approximation and the performances of the proposed analytical scheme.

## Keywords

energy harvest time allocation energy efficiency uplink multiuser throughput maximization analytical expression

# 第五代移动通信系统中下行能量传输和上行无线信息传输的多用户高能效设计

## 创新点

1. 1

建立了能量效率最大化的时间分配数学问题,该问题适用于任意多用户的下行能量传输和上行无线信息传输的多用户传输系统

2. 2

推导得到系统的能量效率函数的上界函数,该函数来能够较紧的逼近原始准确能量效率函数

3. 3

基于界函数,推导出每个用户的上行链路传输无线信息的持续时间,而且得到解析解,该解析解在单用户场景下具有全局最优性,在任意多用户场景下具有渐进最优性。

022305

## References

1. 1.
Xing C, Wang N, Ni J, et al. MIMO beamforming designs with partial CSI under energy harvesting constraints. IEEE Signal Process Lett, 2013, 20: 363–366
2. 2.
Shi H, Wang Y, Song E. Joint beamforming and power splitting for MISO interference channel with SWIPT: an SOCP relaxation and decentralized algorithm. IEEE Trans Signal Process, 2014, 62: 6194–6208
3. 3.
Dong Y, Farnia F, Ozgur A. Near optimal energy control and approximate capacity of energy harvesting communicaiton. IEEE J Sel Areas Commun, 2015, 33: 540–557
4. 4.
Zhang R, Ho C K. MIMO broadcasting for simultaneous wireless information and power transfer. IEEE Trans Wirel Commun, 2013, 12: 1989–2001
5. 5.
Xu J, Zhang R. Throughput optimal policies for energy harvesting wireless transmitters with non-ideal circuit power. IEEE J Sel Areas Commun, 2014, 32: 322–332
6. 6.
Zhou S, Chen T, Chen W, et al. Outage minimization for a fading wireless link with energy harvesting transmitter and receiver. IEEE J Sel Areas Commun, 2015, 33: 496–511
7. 7.
Ju H, Zhang R. Throughput maximization in wireless powered communication networks. IEEE Trans Wirel Commun, 2014, 13: 418–428
8. 8.
Liu P, Gazor S, Kim I M, et al. Noncoherent relaying in energy harvesting communication systems. IEEE Trans Wirel Commun, 2015, 99: 1–14Google Scholar
9. 9.
Liu P, Gazor S, Kim I M, et al. Energy harvesting noncoherent cooperative communications. IEEE Trans Wirel Commun, 2015, 99: 1–6Google Scholar
10. 10.
Xing C, Ma S, Zhou Y. Matrix-monotonic optimization for MIMO systems. IEEE Trans Signal Process, 2012, 63: 334–348
11. 11.
Xing C, Ma S, Fei Z, et al. A general robust linear transceiver design for amplify-and-forward multi-hop MIMO relaying systems. IEEE Trans Signal Process, 2013, 61: 1196–1209
12. 12.
Bai B, Chen W, Cao Z, et al. Outage and energy efficiency tradeoff for multi-flow cooperative communication systems. In: Proceedings of IEEE International Conference on Communications, Sydney, 2014. 10–14Google Scholar
13. 13.
Bai B, Chen W, Cao Z. Energy-spectral efficient transmission policy for energy harvesting nodes with rate requirement. In: IEEE Global Conference on Signal and Information Processing (GlobalSIP), Austin, 2013. 403–406Google Scholar
14. 14.
Yan L, Bai B, Chen W. On energy efficiency maximization in downlink MIMO systems exploiting multiuser diversity. IEEE Commun Lett, 2014, 18: 2161–2164
15. 15.
Kim H, Park E, Park J, et al. Beamforming and power allocation designs for energy efficiency maximization in MISO distributed antenna systems. IEEE Commun Lett, 2013, 17: 2100–2103
16. 16.
Xu Z, Yang C, Li G Y, et al. Energy-efficient CoMP precoding in heterogeneous networks. IEEE Trans Signal Process, 2014, 62: 1005–1017
17. 17.
Fei Z, Ni J, Zhao D, et al. Ergodic secrecy rate of two-user MISO interference channels with statistical CSI. Sci China Inf Sci, 2014, 57: 102302Google Scholar
18. 18.
Zhang C, Ge J, Li J, et al. Robust power allocation algorithm for analog network coding with imperfect CSI. Sci China Inf Sci, 2014, 57: 042312Google Scholar
19. 19.
Valluri S R, Jeffrey D J, Corless R M. Some applications of the Lambert W function to physics. Can J Phys, 2000, 78: 823–831Google Scholar
20. 20.
Scott T C, Mann R, Martinez II R E. General relativity and quantum mechanics: towards a generalization of the Lambert W function. Appl Algebra Eng Commun Comput, 2006, 17: 41–47
21. 21.
Gregson P H. Using angular dispersion of gradient direction for detecting edge ribbons. IEEE Trans Patt Anal Mach Intell, 1992, 15: 682–692
22. 22.
Yi Z, Kim I M. Joint optimization of relay-precoders and decoders with partial channel side information in cooperative networks. IEEE J Sel Areas Commun, 2007, 25: 447–458
23. 23.
Zhang Q, Jin S, Wong K K, et al. Power scaling of uplink massive MIMO systems with arbitrary-rank channel means. IEEE J Sel Top Signal Process, 2014, 57: 841–849Google Scholar