Blind Adaptive Channel Shortening

康奈尔大学C。理查德·约翰逊在C.Richard Johnson，Jr.教授的指导下，康奈尔大学盲均衡研究小组(C.U.Berg)。在过去的15年里，他一直在研究用于通信接收机设计的盲和半盲自适应算法，通常用于盲均衡和盲同步。BERG目前的重点是宽带自适应接收器设计(BARD)项目，该项目旨在为新兴的宽带最后一英里通信应用开发和研究自适应算法。这方面的一个表现就是Berg在发展盲自适应信道缩短算法方面的潮流。信道缩短是均衡的推广，可用于多载波通信系统的接收机设计、降低复杂度的最大似然序列估计(MLSE)的设计和多用户检测器的干扰抑制设计。巴德项目正在采取一种适应系统理论的方法来解决(盲目的)信道缩短问题。通过这种方法，巴德计划最近已经产生了几种盲自适应算法，使得接收机在时变环境中具有更好的性能，并且接收机的复杂度要求大大降低。此外，巴德项目对几种现有的非适应性方法进行了分析，从而解释了它们在某些(时间不变)情况下的(较差)表现，并大幅降低了它们的实施复杂性。

ABSTRACT0310023Cornell UniversityC. Richard JohnsonThe Cornell University Blind Equalization Research Group (C.U. BERG) under the direction of Professor C. Richard Johnson, Jr. has spent the past decade and a half researching blind and semi-blind adaptive algorithms used in communication receiver design, usually for blind equalization and blind synchronization. The current focus of the BERG is the Broadband Adaptive Receiver Design (BARD) Project, which aims to develop and study adaptive algorithms for emerging broadband last-mile communications applications. One manifestation of thisw ork isthe BERG'scurren t e.ort in the development of blind, adaptive algorithmsforchannel shortening.Channel shortening is a generalization of equalization, and it can be applied to the design of receivers for multicarrier communication systems, the design of reduced-complexity maximum likelihood sequence estimation (MLSE), and the design of interference suppression for multiuser detectors. The BARD Project is taking an adaptive system-theory approach to the (blind) channel shortening problem. Through thisapproac h, the BARD Project hasrecen tly produced several blind, adaptive algorithms, leading to receivers with improved performance in timevarying environments, and receivers with greatly reduced complexity requirements. In addition, the BARD Project has analytically characterized several of the existing non-adaptive approaches, leading to both explanations of their (poor) performance in certain (time-invariant) situations, and dramatic reductionsof their implementation complexity.