Working Toward Capacity in Multiple Antenna Radio

在过去的几年里，有大量的研究通过利用发射机和/或接收机的分集和空间复用来提高衰落环境下无线通信的性能。Telatar， Foschini和Gans的开创性工作表明，无线通信系统中的多天线无线电（MAR）可以大大提高性能。MAR成为无线通信经济可行选择的主要障碍是无线电模拟部分的成本。采用复杂信号和信号处理算法的点对点MAR系统已经被设计和建造，并且已经实现了非常接近中断能力的性能。只有考虑到MAR信号和信号处理中模拟电路的成本和复杂性，考虑更复杂的无线传播模型，并将MAR置于网络环境中，MAR才能实现剩余的增益。这项工作的重点是通过利用这些更复杂的模型和网络场景中的结构来推动MAR技术。该工作的目标可以简洁地表述为：1)通信理论通常对固定平均功率的归一化性能感兴趣，但在无线实现中，峰值功率比平均功率更重要。该研究旨在研究多天线无线电中峰值功率约束下的性能和吞吐量优化问题。2)反馈通信可能会在网络场景中显著提高吞吐量和解调器复杂性，特别是在低移动性的环境中（例如，无线计算机网络）。本研究采用经典的科学方法，在真实通道实验和基于实验结果的更现实的理论问题表述之间进行迭代，以接近反馈通信。3)目前无线通信的成本驱动因素是模拟电路。本研究旨在研究将多天线无线电模拟系统的复杂性降至最低的技术。目标是通过以下研究任务来实现：a)用于多天线无线电远程预测的改进信道参数化，b)各种MAR自动重复请求算法的设计和现场测试，c)对拟议的MAR反馈算法进行实验，d)具有恒定包络调制的MAR反馈算法，e)具有有限模拟能力的MAR反馈算法。

Over the past several years, there has been a great deal of research to improve performance of wireless communications in fading environments by exploiting transmitter and/or receiver diversity and spatial multiplexing. The pioneering work by Telatar, Foschini and Gans showed that multiple antenna radios (MAR) in a wireless communication system can greatly improve the performance. The major roadblock to MAR being a financially viable option for wireless communications is the cost of the analog portions of the radio. Point--to--point MAR systems employing complex signaling and signal processing algorithms have been designed and built and have achieved performance very close to the outage capacity. The remaining gains that are achievable in MAR will only be exploited by considering the cost and complexity of analog circuitry in MAR signalling and signal processing, by considering more complex models for wireless propagation, and by putting MAR in networking context. The focus of this effort is to push MAR technology by exploiting the structure in these more complex models and networking scenarios.The objectives of the effort can be succinctly stated as:1) Communication theory is often interested in normalizing performance for a fixed average power but in wireless implementations the peak power is a more critical driver than the average power. The research is examining optimization of performance and throughput with a peak power constraint in multiple antenna radio.2) Feedback communication is likely going to enable a significant improvement in throughput and demodulator complexity in a networked scenario especially in environments with low mobility (e.g., wireless computer networks). This research is approaching feedback communication with a classic scientific method of iterating between experimentation on real channels and more realistic theoretical problem formulations based on the results derived in experimentation.3) The cost driver in wireless communication currently is the analog circuitry. This research is examining techniques that would minimize the complexity of the analog systems in a multiple antenna radio. The objectives are to being met by the following research tasksa) Improved channel parameterization for long range prediction for multiple antenna radio,b) Design and field testing of a variety of MAR automatic repeat request algorithms,c) Experimentation with the proposed feedback algorithms for MAR,d) Feedback algorithms for MAR with constant envelop modulations,e) Feedback algorithms for MAR with limited analog capabilities,