抄録
Multiuser multiple input multiple output (MU-MIMO) systems are attracting attention due to their frequency efficiency. However, in uplink MU-MIMO systems, different frequency offsets among multiple mobile stations (MSs) significantly degrade the transmission quality, especially when orthogonal frequency division multiplexing (OFDM) is used. In this paper, the influence of these frequency offsets is first analyzed in a frequency selective fading environment. Numerical analysis shows that an error floor occurs in the bit error rate and the influence of the frequency offset becomes larger in short delay spread environments. To overcome this problem, a new beamforming method is proposed to compensate for the frequency offset by introducing an auto frequency controller after frequency-space equalization in each data stream. The effect of the proposed method is evaluated in a frequency selective fading environment by computer simulations and measured results.
| 本文言語 | English |
|---|---|
| ページ（範囲） | 2312-2320 |
| ページ数 | 9 |
| ジャーナル | IEICE Transactions on Communications |
| 巻 | E90-B |
| 号 | 9 |
| DOI | |
| 出版ステータス | Published - 2007 9月 |
| 外部発表 | はい |
ASJC Scopus subject areas
- ソフトウェア
- コンピュータ ネットワークおよび通信
- 電子工学および電気工学