MIMO OFDM for broadband fixed wireless access
MIMO OFDM for broadband fixed wireless access
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DOI：
10.1049/ip-com:20040969
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发表时间：
2005-04
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影响因子：
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通讯作者：
T. Willink
中科院分区：
文献类型：
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作者：
T. Willink
宽带多输入多输出 (MIMO) OFDM 系统已针对城市地区高层建筑之间的固定无线链路进行了设计和评估。对典型安装位置的信道测量进行分析以确定相关的空间、时间和频率特性。少量的多径分量导致高空间相关性和有限的空间分集提供频谱效率增益的潜力。然而，缓慢变化的特性支持使用闭环分集方案，例如沿着信道矩阵的本征模的空间复用，以最大化可实现的吞吐量。利用实测信道数据对该方案进行了评估，结果表明信道估计误差引起的自干扰是系统性能的限制因素。考虑到估计误差和反馈延迟，事实证明，即使在这种高度相关的环境中，使用八元件天线也可以将频谱效率相对于单元件天线系统提高三倍。
A broadband multiple-input multiple-output (MIMO) OFDM system has been designed and evaluated for a fixed wireless link between tall buildings in an urban area. Channel measurements for a typical installation location are analysed to determine the relevant spatial, temporal and frequency characteristics. The small number of multipath components leads to a high spatial correlation and limited potential for spatial diversity to provide spectral efficiency gains. However, the slowly-varying characteristics support the use of a closed-loop diversity scheme, such as spatial multiplexing along the eigenmodes of the channel matrix, to maximise the achievable throughput. This scheme is evaluated using the measured channel data, and it is shown that the self-interference caused by channel estimation errors is the limiting factor on the system performance. Taking into account the estimation errors and feedback delay, it is demonstrated that a three-fold increase in spectral efficiency relative to a single-element antenna system is achievable using eight-element antennas, even in this highly correlated environment.