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

由于大量新的和未来的无线业务以及对更高数据速率和同时提高传输质量的不断增长的需求，必须尽可能有效地利用现有的无线信道，以最佳地利用无线通信系统的所有可用自由度来传输信息。为了应对这些日益增加的挑战，信道矩阵的大小（系统成本）和由此可实现的信道容量（最大）之间的平衡。数据速率)必须在避免无线死点（通信的可用性和可靠性）的同时找到。在本研究项目中，利用时变MIMO信道测量和仿真，开发并验证了创新容量优化的天线设计策略。在天线设计策略中引入动态信道测量获得的信息，可以降低天线数量（通信系统的阶数/信道矩阵）和移动通信系统的硬件复杂度。这是因为具有更少但更优化的天线的系统可以实现与启发式设计的多天线系统相同的信道容量[Taz12]。为了实现这一目标，我们应用了少量具有模式可重构天线的发射/接收链，这些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，该系统需要更少的空间和更低的整体系统复杂性，从而降低了硬件和开发成本。同时，由于所描述的天线系统利用了传输信道的显著特征值趋势和特征值群，具有良好的传输特性，因此在系统的可实现互信息率和可用性方面只出现很少或没有损耗。所谓的天线合成将应用于射线追踪信道模拟和信道测量。然后将对结果进行比较和验证。汽车通道的主导方向在一定范围内是静止的，这是一个要求。在[RMSZ13]中描述的街道峡谷中的波导效应就是一个例子。这些平稳特性使得基于天线的优化已经在天线系统的设计阶段，不需要任何自适应信道估计与动态适应在正在进行的通信。基于这些设计策略，可以设计出模式可重构的车载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.