Multiple-symbol detection of MPSK in narrow-band interference andAWGN

We propose a new technique for rejection of narrow-band interference (NBI) based on multiple-symbol detection of coherent or differential phase-shift keying (DPSK). We first show that the direct use of multiple-symbol detection offers poor performance when NBI is dominant. Our proposed technique employs a special signaling or coding scheme which is shown to be robust against NBI. The evaluation of bit-error rate (BER) shows significant performance improvement in NBI vis-a-vis direct multiple-symbol detection. When viewed as a coding scheme, the proposed signaling scheme is significantly simpler for achieving the same coding gain than conventional error correction codes     

Performance evaluation and application of channel offset schemes inindoor channel assignments

We deal with channel offset schemes and their application in three-dimensional (3-D) frequency reuse environments with ideal cubic microcells. Formulas are derived to calculate channel reuse distances (CRDs) and interchannel usage distances (IUDs) for a given offset degree. For an indoor personal communication network (PCN), an algorithm is proposed for fixed channel assignment with channel offset. The spectral efficiency of channel offset schemes is discussed and the results show that compared to the channel offsetless scheme, channel offset schemes make more efficient use of limited spectrum resources     

激发相干态及其叠加态与二能级原子的作用研究

本文研究了光场初态为激发相干态或其叠加态时强度耦合Jaynes－Curnmings模型的动力学演化。对原子反转以及光场的反聚束效应进行了讨论．     

MMail系统的设计与实现

本文介绍了多媒体电子邮件系统的实现方案。     

无电极放电灯的发展动态

无电极放电灯是新一代电光源，具有结构简单、无电极、高光效、高显色性能和长寿命等特性，已发展成为无电极荧光灯、无电极金属卤化物灯和微波硫灯等几种类型。本文主要介绍这些无电极放电灯的发光原理、放电类型、灯的结构、特性和发展动态。     

准分子激光角膜原位磨镶术治疗高度近视

本对８６例１６２只眼屈光度平均为－１１．２８±５．１１Ｄ（－６００－２７００Ｄ）高度近视行准分子激光角膜原位磨镶术（ＬＡＳＩＫ），术后半年视力、屈出度与术前比较，明术后视力、屈光度变化有规律性、分析影响疗效的因素，肯定ＬＡＳＩＫ术矫正高度近视有效、安全、预测性强、稳定性好，并发症少。     

多级放大频分复用系统中四波混频串扰的消除

本文从理论上研究了四波混频在多级放大频分复用光通信系统中的特性，提出了一种消除四波混频串扰的新方法，该方法只需适当选择信道间隔，无需增添其它器件，因而更有利于在实际光通信系统当中的应用。     

北京电话号码查询系统

本文介绍了新建的北京电话号码查询系统，内容包括系统配置、工作流程以及排队机、查询数据库、管理系统和系统连接功能等特点，并介绍了系统可拓展的业务。     

A bidirectional vector associative memory architecture with application to neural networks

A bidirectional architecture for associative memory (AM) capable of vector arithmetic operations is proposed. By introducing a pair of masking and tagging mechanisms, the conventional concepts of bit-operations and word-operations in AM have been generalized to row and column operations, respectively. The proposed architecture demonstrates a symmetrical functionality such that associative processing can be performed in both column and row directions. A set of built-in vector arithmetic and logic units (VALU) is designed to perform the basic vector operations, which offers O(max{n, m}) speed-up for vector operations over the conventional AM at an O(n + m) cost for realizing an n × m AM array. As an applicational example, an associative processing implementation for artificial neural networks is presented.     

Bounded gray-level morphology and its applications to imagerepresentation

Morphological skeletonization and decomposition are two well-known schemes for binary image representation, but they are not compact for gray-level images. In this correspondence, bounded gray-level morphology is used to improve their performances for gray-level image representation. Experimental results show that bounded gray-level morphology efficiently reduces the number of skeleton points and the entropy of morphological decomposition.