Interpolation based transmit beamforming for MIMO-OFDM with limited feedback
Interpolation based transmit beamforming for MIMO-OFDM with limited feedback
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DOI：
10.1109/icc.2004.1312489
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发表时间：
2004-06
影响因子：
5.4
通讯作者：
Jihoon Choi;R. Heath
中科院分区：
文献类型：
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作者：
Jihoon Choi;R. Heath
发射波束成形和接收组合是在多输入多输出正交频分复用 (MIMO-OFDM) 系统中利用空间分集的简单方法。最佳波束成形需要每个 OFDM 子载波的波束成形矢量形式的信道状态信息。本文提出了一种结合波束成形矢量量化和智能矢量插值的有限反馈架构。在所提出的系统中，接收器将有关最佳波束成形向量的一小部分信息发送到发射器，并且发射器通过插值计算所有子载波的波束成形向量。开发了一种新的球形插值器，它利用相位旋转参数来满足传输波束成形矢量的相位不变性和单位范数属性。波束成形矢量和相位参数在接收机处被量化，并且量化的信息被提供给发射机。与同类方法相比，所提出的量化系统仅在复杂性方面略有增加。数值模拟表明，在相同的反馈数据速率下，所提出的方案比现有的分集技术表现更好。
Transmit beamforming and receive combining are simple methods for exploiting spatial diversity in multiple-input multiple-output orthogonal frequency division multiplexing (MIMO-OFDM) system. Optimal beamforming requires channel state information in the form of the beamforming vectors for each OFDM subcarrier. This paper proposes a limited feedback architecture that combines beamforming vector quantization and smart vector interpolation. In the proposed system, the receiver sends a fraction of information about the optimal beamforming vectors to the transmitter and the transmitter computes the beamforming vectors for all subcarriers through interpolation. A new spherical interpolator is developed that exploits parameters for phase rotation to satisfy the phase invariance and unit norm properties of the transmitted beamforming vectors. The beamforming vectors and phase parameters are quantized at the receiver and the quantized information is provided to the transmitter. The proposed quantization system provides only a moderate increase in complexity versus over comparable approaches. Numerical simulations show that the proposed scheme performs better than existing diversity techniques with the same feedback data rate.