Leech格的限界距离译码

本文利用将Ｌｅｅｃｈ格投影于ＧＦ（４）得到（６，３，４）Ｈｅｘａｃｏｄｅｘ这一性质，提出一种新的Ｌｅｅｃｈ格的限界距离译码算法，复杂度为最多１１５１次，最少５７５次，平均９１１次实数运算，而目前已知最快的ＢＤ译码算法复杂度为最多１００７次，最少９１１次运算，平均９５３次，新算法在平均和最少复杂度方面有所降低，计算机模拟表明新算法相对于最在似然译码仅有０．０２ｄＢ的编码增益损失，而文献（１０）中算法     

A co-designed coding,modulation and equalization scheme for the transmission of 155-52 Mbit/s data over a 72 MHz intelsat transponder. Part 1: Coding and modulation performance

This paper reports on the application of co-designed coding, modulation and equalization techniques to an INTELSAT requirement for transmitting 155-52 Mbit/s data over a 72 MHz satellite channel. A specific solution as regards coding, modulation and equalization is proposed and analysed that differs from ‘standard’ concatenation in that the inner decoder integrates equalization, modulation and coding. In Part 1 results of extensive computer simulations are presented, examining the effect of adjacent channel interference, co-channel interference, non-linear distortion in representative ground and space TWTAs, multiplexers and filter distortion. In Part 2 a novel technique for integrating decision feedback equalization into the inner decoder is described. The gains in integrating the coding and equalization are shown to be significant for channels that need equalizing.     

Leech的语义分类法在大学英语词汇教学中的应用

本文针对大学英语词汇教学中普遍存在的问题,提出了富有建设性的建议:即利用Leech对语义分类的理论来指导大学英语词汇教学。作者指出词汇教学不仅要让学生了解词汇表上的词义,更重要的是要从文化的角度,让学生理解并掌握词汇所承载的深刻的文化内涵。只有这样,学生才能切实提高实际运用语言的能力。     

Square-free partial words

We say that a partial word w over an alphabet A is square-free if every factor xx^′ of w such that x and x^′ are compatible is either of the form ?a or a? where ? is a hole and a∈A. We prove that there exist uncountably many square-free partial words over a ternary alphabet with an infinite number of holes.     

A co-designed coding,modulation and equalization scheme for the transmission of 155-52 Mbit/s data over a 72 MHz intelsat transponder. Part 2: Equalization

This paper reports on the application of co-designed coding, modulation and equalization techiques to an INTELSAT requirement for transmitting 155-52 Mbit/s data over a 72 MHz satellite channel. A specific solution as regards coding, modulation and equalization is proposed and analysed that differs from ‘standard’ concatenation in that the inner decoder integrates equalization, modulation and coding. In Part 2, a novel technique for integrating decision feedback equalization into the inner decoder is described. The gains in integrating the coding and equalization are shown to be significant for channels that need equalizing.