Single-carrier and multi-carrier cooperative diversity techniques for next generation HF communication systems

2005年卡特里娜飓风袭击美国墨西哥湾沿岸时，严重破坏了将该地区与外界隔绝的电信基础设施。飓风所至之处，几乎所有的高端应急通讯设备、911呼叫中心、手机信号塔和固定电话线都被摧毁，高频业余无线电系统在救援和恢复行动中发挥了关键作用。随后的美国国会听证会强调，业余无线电的反应是救灾工作中为数不多的正确例子之一。这些悲惨事件使人们重新认识到“古老的”高频技术，这种技术自无线电出现以来一直是全世界信息传输的重要组成部分。在这个高科技信息时代，高频通信继续广泛用于民用、政府和军事应用，作为无数更复杂的通信系统的强大替代品。高频系统传统上与模拟语音和极低速率数据传输有关。随着语音通信从模拟向数字的转变以及对高速数据传输（如电子邮件、互联网、FTP）的需求不断增加，高频通信正在经历复兴。需要创新技术来突破高频频段的容量极限。我们的研究计划旨在填补这一领域的研究空白，研究合适的空中接口架构，这些架构将能够支持下一代高频通信系统的挑战性期望。

When Hurricane Katrina hit the Gulf Coast of United States in 2005, it severely damaged the telecommunications infrastructure isolating the area from outside world. With nearly all the high-end emergency communications gear, 911 call centers, cellphone towers, and fixed phone lines being knocked out by the hurricane in its path, HF (high-frequency) amateur radio systems played a critical role in rescue and recovery operations. Subsequent American congressional hearings highlighted the amateur radio response as one of the few examples of what went right in the disaster relief effort. Such tragic incidents have resulted in re-appreciation of the "good old" HF technology which has been an essential part of worldwide information transmission since the advent of radio. In this high-tech information age, HF communication continues to be used for a wide range of civilian, government, and military applications as a powerful alternative to a myriad of more sophisticated communication systems. HF systems have been traditionally associated with analog voice and very-low-rate data transmission. With the shift from analog to digital in voice communication and increasing demands for high-rate data transmission (e.g., e-mail, internet, FTP), HF communication has been going through a renaissance. Innovative techniques are required to push the capacity limits of HF band. Our research proposal aims to fill the research gap in this area investigating suitable air interface architectures which will be able to support the challenging expectations in next generation HF communication systems.