Antenna systems with reduced order based on stationary eigen-value optimization (OASE)

由于大量的新的和未来的无线服务以及对更高的数据速率和同时提高的传输质量的不断增长的需求，必须通过最佳地利用无线通信系统的所有可用自由度来尽可能有效地使用现有的无线信道来传输信息。为了满足这些日益增长的挑战，需要在信道矩阵的大小（系统成本）和由此可实现的信道容量（最大信道容量）之间取得平衡。在本研究项目中，我们开发了创新的容量优化天线设计策略，并使用时变MIMO信道测量和仿真进行了验证。通过在天线设计策略中涉及通过动态信道测量获得的信息，可以减少天线的数量（通信系统的阶数/其信道矩阵）和移动的通信系统的硬件复杂度。这是由于这样一个事实，即具有更少但更优化的天线的系统可以实现与按比例设计的多天线系统相同的信道容量[Taz 12]。为了实现这一目标，我们应用了几个发射/接收链与模式可重构天线，可以在固定的辐射模式之间切换。与具有自适应波束形成的相位控制天线阵列相比，这需要更少的空间和更低的整个系统的复杂性，并且因此降低了硬件和开发成本。同时，关于可实现的互信息速率和系统的可用性，应该只出现很少的损耗或不出现损耗，因为所描述的天线系统利用了具有有利传输特性的传输信道的显著本征值趋势和本征值组。所谓的天线合成将应用于射线跟踪信道模拟和信道测量。之后将进行比较和验证结果。汽车信道中的主导方向在某些限制内是静止的，这是一个要求。[RMSZ 13]中描述的街道峡谷中的波导效应就是一个例子。这些固定特性使得已经在天线系统的设计阶段中的基于天线的优化成为可能，其在正在进行的通信期间不需要具有动态适应的任何自适应信道估计。基于这些设计策略，可以设计用于车辆的方向图可重构SISO和MIMO天线系统。

Due to the large number of new and future wireless services and the ever increasing demand for higher data rates with simultaneously increasing transmission quality, the existing wireless channel must be used as efficiently as possible for the transmission of information by utilizing all the available degrees of freedom of a wireless communication system optimally. In order to meet these increasing challenges, a balance between the size of the channel matrix (the system cost) and the hereby achievable channel capacity (max. data rate) must be found while avoiding wireless dead spots (availability respectively reliability of the communication).In this research project, innovative capacity optimized antenna design strategies are developed and verified with the use of time-variant MIMO channel measurements and simulations. By involving information obtained by dynamic channel measurement in the antenna design strategy, the number of antennas (the order of the communication system / its channel matrix) and the hardware complexity of the mobile communication system can be reduced. It is due to the fact that a system with fewer but more optimized antennas can achieve the same channel capacity as a heuristically designed multi-antenna system [Taz12]. To achieve this goal we apply few transmit / receive chains with pattern reconfigurable antennas that may switch between fix radiation patterns. That requires less space and less complexity of the overall system and therefore reduces the hardware and development costs compared to a phase controlled antenna array with adaptive beam-forming. At the same time concerning the achievable mutual information rate and availability of the system only few or no losses should appear, because the described antenna system utilizes the significant eigenvalue trends and eigenvalue groups of the transmission channel, which possess the favorable transmission characteristics. The so-called antenna synthesis will be applied on ray-tracing channel simulations and on channel measurements. Afterwards there will be a comparison and a verification of the results. Predominant directions in automobile channels that are stationary within some limits are a requirement for this. The waveguide effect in street canyons as described in [RMSZ13] is one example for that. These stationary characteristics enable an antenna based optimization already in the design phase of the antenna system that does not need any adaptive channel estimation with dynamic adaption during ongoing communication. Based on these design strategies pattern reconfigurable SISO and MIMO antenna systems can be designed for vehicles.