Power Combining Networks for MIMO Transmission

用于 MIMO 传输的功率组合网络

• 批准号: 1256548
• 负责人: Andrea Goldsmith
• 金额: $ 26.52万
• 依托单位: Stanford University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-02-01 至 2015-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1256548&HistoricalAwards=false
• 关键词: Power; Combining; Networks; MIMO; Transmission

This research studies the use of power combining in multi-antenna radios. Modern radio systems often use multiple transmit antennas and appropriate signal coding to improve throughput and reliability of wireless links. Ideally, each amplifier should be rated at the maximum total (or sum) power that can be transmitted from all antennas. Due to cost and efficiency considerations, the power rating is usually designed to be lower (typically the maximum total power divided by the number of antennas), and this can lead to significant performance loss. This research explores a solution using Power Combining Networks (PCN) that enable the output of an amplifier to be switched/combined into any antenna, thus moving power from a weaker to a stronger antenna, resulting in improved link performance.The maximum output power of a MIMO (Multiple Input, Multiple Output) antenna transmitter is limited due to bio-safety considerations. MIMO transmission performs best when each power amplifier is rated at the full system transmit power. If the amplifiers are fractionally rated due to cost and efficiency considerations, the worst case loss with M antennas can reach log M dB in the presence of channel imbalances. A PCN can reduce this loss significantly, trading the loss of array gain for a better channel coupling efficiency. Use of a PCN alters the effective MIMO channel and therefore can also change the optimum transmit coding. The goal of this research is to study fast algorithms for PCN selection, appropriate signal coding schemes and the best realizable performance.

本研究探讨功率合成技术在多天线无线电系统中的应用。现代无线电系统通常使用多个发射天线和适当的信号编码来提高无线链路的吞吐量和可靠性。理想情况下，每个放大器的额定功率应该是所有天线可以发射的最大总功率。由于成本和效率的考虑，额定功率通常被设计得较低（通常是最大总功率除以天线的数量），这可能导致显著的性能损失。本研究探讨了一种使用功率合并网络（PCN）的解决方案，该网络使放大器的输出能够被切换/合并到任何天线中，从而将功率从较弱的天线移动到较强的天线，从而改善链路性能。由于生物安全考虑，MIMO（多输入，多输出）天线发射机的最大输出功率受到限制。当每个功率放大器额定为全系统发射功率时，MIMO传输性能最佳。如果放大器由于成本和效率考虑而被分数额定，则在存在信道不平衡的情况下，M个天线的最坏情况损耗可以达到log M dB。PCN可以显著降低这种损耗，以阵列增益的损耗换取更好的信道耦合效率。PCN的使用改变了有效的MIMO信道，因此也可以改变最佳发送编码。本研究的目标是研究快速的PCN选择算法，合适的信号编码方案和最佳的可实现性能。