Journal on Communications ›› 2014, Vol. 35 ›› Issue (2): 125-136.doi: 10.3969/j.issn.1000-436x.2014.02.017

• academic paper • Previous Articles     Next Articles

Analysis of spectral efficiency of multiuser MISO downlink based on large-scale antennas

Ju-fang LI1,Rui ZHAO1,Bin JIANG2,Yong-ming HUANG2,Lv-xi YANG2,Hai ZHANG1   

  1. 1 School of Information Science and Engineering, Huaqiao University, Xiamen 361021, China;
    2 School of Information Science and Engineering, Southeast University, Nanjing 210096, China
  • Online:2014-02-25 Published:2017-07-25
  • Supported by:
    The National Natural Science Foundation of China;The National Natural Science Foundation of China;The National Natural Science Foundation of China;The National Natural Science Foundation of China;Fundamental Research Funds for the Central Universities;Science and Technology Innovation Platform Funds of Fujian Province;High-Level Personnel Start Research Projects of Huaqiao University

Abstract:

The spectral efficiency of the downlink of multi-user multiple-input and single-output (MU-MISO) was ana-lyzed in the time-division duplex (TDD) communication systems with large-scale antennas. Assuming that the number of users was fixed and the antenna number (M) of base station (BS) increases without limit, the conclusions through theo-retical derivations and analyses were drawn that, when the transmit power of the BS reduces to 1/M of that of BS with single antenna, the system spectral efficiency tends to a constant value with the increase of M if the BS acquires the per-fect channel state information (CSI). The adverse effects of the inter-user interferences and the fast fading could also be eliminated through simple pre-processings. Although the multicell system is affected by the pilot contamination, which is the reason why the inter-cell interferences cannot be eliminated, the reduced transmit power makes the system changed from interference-limited to noise-limited. The limit expression of the system spectral efficiency using zero-forcing (ZF) normalized precoding is equal to that using maximum ratio transmission (MRT) normalized precoding. Finally, the lower bound of the spectral efficiency of multi-user downlink applying space time block code was presented and the correctness of the above conclusions was confirmed by the simulation analyses.

Key words: large-scale antennas, multi-user multiple-input and single-output, spectral efficiency, pilot contamination, zero-forcing precoding

No Suggested Reading articles found!