Exploiting Diversity Gain Through MIMO Radar and Sonar Signal Processing

最近，研究人员考虑将为无线通信系统开发的多输入多输出(MIMO)技术应用于雷达场景。在MIMO系统中，发送端和接收端都使用多根天线来提高数据速率，减小无线信道随时间快速变化的影响。在雷达系统中，单基地或双基地MIMO雷达可用于减少闪烁效应的影响，方法是从多个发射天线照射目标，但具有相同的总发射机功率预算。MIMO雷达还可以通过同时发射多个波形来减少搜索目标的时间，从而可以更有效地搜索发射角。此外，MIMO处理增加了雷达系统的有效自由度，因此可以提高对雷达系统中的地面回波、声纳系统中的海底回波以及人为/人为干扰源的容忍度。自MIMO雷达概念出现以来，国际活动的重点既是基本理论，确认可能在探测和分辨率性能方面取得的重大潜在收益，也是开发信号处理算法，以促进这些收益。我们在这里建议的是利用我们已经在以下方面所做的工作：(I)计算现实MIMO雷达或声纳场景中的检测性能的方法；(Ii)不需要二次训练数据的基于雷达阵列的信号处理的自适应检测技术。我们解决了尚未解决的研究问题，这些问题的解决将促进MIMO雷达概念的工业开发。具体地说，这些是：(I)设计相关控制的恒幅MIMO波形；(Ii)开发能够在未知杂波统计的环境中工作的自适应接收器算法，并且能够在各个tr/rx对之间的有限带宽通信信道的约束内工作。这项工作的另一个新方面将是在声纳环境中应用和评估MIMO概念。我们建议的是一种严格的通用方法来理解和应用MIMO检测。结果将在雷达和声纳应用中使用针对目标和介质的详细计算机模拟技术进行测试和验证。在声纳的情况下，它们也将用测量数据进行测试。

Recently, researchers have considered the application of multiple-input multiple-output (MIMO) techniques developed for wireless communication systems to the radar scenario. In MIMO systems, multiple antennas are employed at both transmitter and receiver to increase the data rate and reduce the effect of rapid changes in the radio channel with time. In the context of radar systems, mono-static or bi-static MIMO radars could be used to reduce the impact of scintillation effects, by illuminating the target from multiple transmit antennas but with the same total transmitter power budget. MIMO radars could also reduce the search time to find targets by transmitting multiple waveforms simultaneously, which allows more efficient searching of transmit angle. Further, MIMO processing increases the effective degrees of freedom in the radar system and may thus increase tolerance to echoes from the ground in radar systems and from the sea floor in sonar systems as well as deliberate man/made sources of interference. Since the emergence of MIMO radar concept international activity has focused both on the underlying theory, confirming the significant potential gains in detection and resolution performance that might be achieved, and on developing signal processing algorithms to facilitate these gains. What we propose here is to exploit the work we have already done in (i) methodologies for calculating detection performance in realistic MIMO radar or sonar scenarios; (ii) adaptive detection techniques for radar array-based signal processing that do not require secondary training data. We address the open research questions whose solution will facilitate industrial exploitation of the MIMO radar concept. In particular these are: (i) the design of correlation controlled constant amplitude MIMO waveforms; (ii) the development of adaptive receiver algorithms capable of working in environments of unknown clutter statistics and within the constraints of limited bandwidth communication channels between individual TR/RX pairs. A further novel aspect of the work will be the application of and assessment of MIMO concepts in sonar environments. What we propose is a rigorous generic approach to the understanding and application of MIMO detection. The results will be tested and validated in radar and sonar applications using detailed computer modelling techniques for both target and the medium. In the sonar case they will also be tested with measured data.