2005 Fiscal Year Final Research Report Summary
Studies on High-speed Radio Transmission Using MIMO-OFDM (Multiple Input Multiple Output-Orthogonal Frequency Division Multiplexing) Systems
| Project/Area Number |
15360198
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Communication/Network engineering
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| Research Institution | HOKKAIDO UNIVERSITY |
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Principal Investigator |
OGAWA Yasutaka Hokkaido Univ., Grad.School of Information Science and Technology, Prof., 大学院・情報科学研究科, 教授 (70125293)
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| Co-Investigator(Kenkyū-buntansha) |
OHGANE Takeo Hokkaido Univ., Grad.School of Information Science and Technology, Asso.Prof., 大学院・情報科学研究科, 助教授 (10271636)
NISHIMURA Toshihiko Hokkaido Univ., Grad.School of Information Science and Technology, Inst., 大学院・情報科学研究科, 助手 (70301934)
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| Project Period (FY) |
2003 – 2005
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| Keywords | MIMO / OFDM / Space division multiplexing / Fading / Eigen-beam space division multiplexing / Channel estimation / Electromagnetic wave propagation / Frequency offset |
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| Research Abstract |
1. Evaluation of the channel estimation and BER performance using an experimental system :
An OFDM demodulation system was built up using DSP boards. Experimentally, we validated the OFDM channel estimation scheme proposed by our group. The channel was calculated by FFT applying to the impulse response obtained by the minimum square error method in the time domain. Then, we evaluated the bit error rate (BER) performance of the proposed OFDM system. Also, we examined an ordered successive detection method and transmission with error correcting codes.
2. Joint estimation of channel and frequency offset :
We proposed a joint estimation scheme of the channel and frequency offset using only 4 OFDM training symbols. It was shown that we can estimate them accurately and can obtain good BER performance.
3. Reduction of the amount of channel state information (CSI) feedback :
Eigenbeam-space division multiplexing (E-SDM) requires the feedback of CSI in frequency division duplex systems. In order to reduce the amount of the feedback, we proposed a new scheme. The scheme estimates the impulse response using the minimum square error method in the time domain, and feedback the impulse response. This reduces the amount of CSI feedback comparing with the feedback of all the subcarrier channel.
4. Evaluation of MIMO propagation :
The performance of MIMO systems depends on electromagnetic wave propagation environments. We conducted propagation measurement in line-of-sight (LOS) and nonline-of-sight (NLOS) environments. It was shown that the BER performance is better in LOS environments than that in NLOS ones. However, it was also shown that the performance depends highly on the MIMO configurations in LOS environments.
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