Research at the Frontier of the Physical Layer

网络协议栈的物理层是指通过诸如电线(例如双绞线或同轴电缆)、电磁波(例如卫星应答器、蜂窝/PCS塔或无线局域网(WLAN)基站)或记录介质(例如磁盘或光盘)之类的物理介质发送和接收的信号。从物理介质的角度来看，该研究具有宽泛的视角，而狭隘的焦点在于所解决的问题都涉及一种形式的前向差错控制(FEC)。本文的研究主要集中在三个方面：代数编码Turbo码差错控制编码问题的数学方法和分析算法在第一个主题领域，主要研究了交织的理论和实践，一种新的计算二进制卷积码重量分布的方法，以及在有和没有信道状态辅助信息的情况下的无线信道容量问题。第二个主题领域涉及代数几何(AG)编码领域的基本理解和进展。这些AG码显示出在传输系统中的应用潜力。需要进一步了解，以便能够实际执行AG代码。在最后的主题中，确定了“Turbo编码”的新应用，包括具有存储器和Turbo编码调制的系统。

The physical layer of the network protocol stack refers to the signals transmitted, and received, over a physical medium, such as a wire (e.g. a twisted pair of wires or a coaxial cable), an electromagnetic wave (e.g. a satellite transponder, a cellular/PCS tower or a wireless local area network (WLAN) base station), or a recording medium (e.g. magnetic or optical disks). The research has a broad perspective, from the viewpoint of the physical medium, and a narrow focus in that the problems addressed all involve a form of forward error control (FEC). The research is directed in three areas: Mathematical methods and analysis algorithms for coding Problems in algebraic coding Turbo code error control In the first topic area, the following are considered: theory and practice of interleaving, a novel method for computing the weight distribution of a binary convolutional code, and problems concerning the capacity of wireless channels with and without side information on channel state. The second topic area concerns basic understanding and advances in the area of algebraic geometry (AG) coding. These AG codes show potential for application in transmission systems. Further understanding needs to be developed to enable the practical implementation of AG codes. In the final topic, new applications of "turbo coding" are identified, including systems with memory and turbo coded modulation.