講演抄録/キーワード |
講演名 |
2017-10-24 14:00
[ポスター講演]A Study on Beam Pattern of Array with Multi-User MIMO Using Null-Space Expansion Tolerant to Channel Fluctuation Hironori Ban・Daisuke Motegi・○Makoto Taromaru・Mai Ohta(Fukuoka Univ.) SR2017-89 SRW2017-39 |
抄録 |
(和) |
Some papers reported that a zero-forcing (ZF) adaptive array antenna or multi-user MIMO system can be robust against channel variation due to fading and/or movement of the interfering terminals when the combining weights are set to cancel not only the most recent channels but also the previous ones of the interferences. This method is called “Null-Space Expansion” proposed by NTT. This report discusses the mechanism canceling the interferences focusing on the relation between the beam pattern formed by the MIMO weight and the incident waves of the propagation model. This report shows by computer simulations that the ZF weight vector both for the latest past interference channels additional to the present one is inclined to form nulls toward angle of arrival (AoA) of each the incident waves and the direct (line-of-sight) wave from the interference terminals. We also evaluate and discuss this phenomenon with the theoretical expressions. Those studies explain that Null-Space Expansion can be tolerant to channel fluctuation because the combining weight forms the beam pattern with nulls toward the AoA of each incident wave of the interferences which moves much slower than the phase fluctuation due to Doppler shift. |
(英) |
Some papers reported that a zero-forcing (ZF) adaptive array antenna or multi-user MIMO system can be robust against channel variation due to fading and/or movement of the interfering terminals when the combining weights are set to cancel not only the most recent channels but also the previous ones of the interferences. This method is called "Null-Space Expansion" and proposed by NTT. This report discusses the mechanism canceling the interferences focusing on the relation between the beam pattern formed by the MIMO weight and the incident waves of the propagation model. This report shows by computer simulations that the ZF weight vector both for the latest past interference channels additional to the present one is inclined to form nulls toward angle of arrival (AoA) of each the incident waves and the direct (line-of-sight) wave from the interference terminals. We also evaluate and discuss this phenomenon with the theoretical expressions. Those studies explain that Null-Space Expansion can be tolerant to channel fluctuation because the combining weight forms the beam pattern with nulls toward the AoA of each incident wave of the interferences which moves much slower than the phase fluctuation due to Doppler shift. |
キーワード |
(和) |
アダプティブアレーアンテナ / MIMO / ビームパターン / ゼロフォーシング / ヌル空間 / / / |
(英) |
adaptive array antenna / MIMO / beam pattern / zero-forcing / null space / / / |
文献情報 |
信学技報, vol. 117, no. 257, SR2017-89, pp. 63-64, 2017年10月. |
資料番号 |
SR2017-89 |
発行日 |
2017-10-16 (SR, SRW) |
ISSN |
Print edition: ISSN 0913-5685 Online edition: ISSN 2432-6380 |
著作権に ついて |
技術研究報告に掲載された論文の著作権は電子情報通信学会に帰属します.(許諾番号:10GA0019/12GB0052/13GB0056/17GB0034/18GB0034) |
PDFダウンロード |
SR2017-89 SRW2017-39 |
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