地理信息系统在有线电视网络中的应用

有线电视网络具有明显的地理特征，与地理信息系统结合建立可视化CATV GIS系统，对网络辅助设计、日常维护、用户管理、图纸查询、模拟分析等极为便利，也为有线电视网络运营和管理提供了有效手段，简述安庆有线电视地理信息系统的建立和实际应用。     

SIR Weighting Combining Diversity Using Matched Filter for Personal Communication Systems

We propose a novel SIR weighting postdetection combining diversity scheme with a new accurate SIR estimation method. The SIR is estimated and used as the weighting factor to compensate severe cochannel interference, one of the most important issues for PCS in terms of frequency utilization. Theimprovement offered by the proposal depends on SIR estimation accuracy.The SIR is, in this paper, estimated by a matched filter where theauto-correlation between received signal and unique word is calculated. Computer simulationsconfirm that the SIR of each diversity branch can be estimated easily andaccuratelyby the proposed SIR estimation method. The proposed diversity scheme achievesaperformance very close to that of ideal SINR weighting diversity underRayleighfading with severe cochannel interference. When average SIR = 10 dB and thenumber of branches(L)=4, the proposed diversity scheme lowers the requiredE_b/N₀ by 5 dB at BER = 1×10^-3compared to conventional maximal ratio combining diversity. This paper alsopresentsthe unique word length required to realize adequate performance, i.e.,robustnessagainst high-pitch Rayleigh fading.     

光纤级联系统中准孤子传输的数值模拟

本文基于一种光纤级联系统模型,用数值模拟方法考察准孤子在这种中的传输情况,得到了传输１００００ｋｍ的最佳方案并给出了当输入光脉冲的峰值功率、初始宽及啁啾变化时,系统的传输特性     

馈源阵面排列对偏置多波束天线特性的影响

以３７单元馈源阵为例,就用于卫星移动通信系统中的偏置多波束天线进行分析探讨：在原有两种馈源阵阵面排列形式的基础上,又提出了第三种排列形式,即馈源阵的球面排列形式,并对这三种形式下偏置多波束天线的远场特征进行了计算比较,得出了一些有益的结论;另外,将馈源阵阵面适当地偏离焦点也可使多波束天线的远场特性得以改善。     

民用房屋改造成移动通信机房应注意结构的安全

通过工程调查发现，一些民用房屋改造成移动通信机房过程中由于设备布置不当，对结构构件的安全产生严重的影响，针对一具体问题进行楼板承栽力计算分析并提出相应的处理措施，供设计人员探讨。     

流密码的现状和发展

密码技术，特别是加密技术是信息安全技术的核心。文中简要介绍了流密码的原理及种类，并对其设计准则及检验标准做了论述，接着概括了该领域的最新进展和成果，最后对其发展趋势进行了分析展望。     

Incremental-based Nonlinear Detection Algorithm for MIMO System

A novel incremental nonlinear detection algorithm is presented for Multiple-Input Multiple-Output （MIMO） system. In this algorithm, the received data at multiple receiver antennas are nonlinearly mapped and then summed with weights. The weight coefficients are incrementally computed to avoid direct computation of the inverse of a matrix, which greatly reduce the computational complexity. Simulation and comparison show that the proposed algorithm can obtain better performance of Bit Error Rate （BER） than linear Minimum Mean Square Error （MMSE）.     

Research on Marketing Channel of Mobile Manufacturer Based on Analytic Hierarchy Process

Research on ＂marketing channel＂ of mobile attracts much attention in these years, but there＇re only few articles referring to how to optimize the disposition of channel resources for mobile manufacturers. Based on a typically multiplex marketing channel system of mobile manufacturer, the analytic hierarchy process （~HP） structure model is established. Through the judgment matrix, simple and total hierarchy arrangement, consistent test, this paper gets the weight of each kind of marketing channel of mobile manufacturer, it provides the practical reference value for mobile manufacturers to distribute resources of marketing channels.     

Optical Single-Sideband Modulators and Their Applications

We review our recent work in the implementation of optical single-sideband (OSSB) modulation and in the application of this modulation format to microwave photonics and optical testing systems. We have developed an enhanced OSSB modulator for wide-band operation, the so-called bidirectional OSSB modulator, and a simplification of this scheme for narrow-band applications. These OSSB modulators are based on the use of a standard single-electrode Mach-Zehnder electro-optic modulator (MZ-EOM) and passive fiber-optic components. In both designs, the OSSB operation is shown to be independent of the MZ-EOM bias. Therefore, the optical modulation depth at the output of the device can be enhanced using minimum transmission biasing to provide suppression of the optical carrier. Finally, we demonstrate the application of OSSB modulators to the improvement of microwave/millimeter-wave subcarrier multiplexing fiber-optic links and to narrow-band fiber radio systems. In addition, we analyzed the feasibility and the limitations of an optical vector network analysis technique based on OSSB modulation that can provide sub-picometer wavelength resolution.     

Optimizing the performance of single-mode laser diode system using genetic algorithm

In this correspondence, micro-genetic algorithm (MGA) application results for optimizing the performance of electronic feedback of a laser diode are presented. The goal of optimization is to find the maximum bandwidth of the laser diode with electronic feedback used in fiber optic digital communication. A numerical analysis of the system theory of the single-mode laser diode to obtain numerical results of the gain, the pulse response, and the harmonic distortion for electronic feedback is also presented. The dependence of the system gain on the feedback gain and delay is examined. The pulse response is studied and it is shown that a transmission rate over 1 Gbyte/s can be achieved.