沿海高层建筑内覆盖质量的优化方案和案例

高层建筑内手机用户的使用感知质量情况,一直是无线网络优化工作研究的课题。随着城市的建设的快速发展,一些沿海城市海景楼、海景酒店林立而起,沿海高层建筑周边的CDMA质量覆盖技术也形成了新的研究课题。主要介绍几种高层导频污染和弱覆盖问题解决的优化方案和案例,从中提炼CDMA无线优化提供参考经验。     

Pilot design for sparse MIMO-OFDM channel estimation with generalized shift invariance property

Compressed sensing (CS) based channel estimation is greatly bound by the measurement matrix according to CS theory. We design pilot patterns by minimizing the mutual coherence of the measurement matrix with the generalized shift invariance property (GSIP). GSIP and a corollary are firstly proposed. Then two pilot pattern design schemes termed pilot design with GSIP (PDGSIP) and tradeoff pilot design with GSIP (TPDGSIP) are put forward to design orthogonal pilot patterns based on GSIP for a multiple-input multiple-output orthogonal frequency division multiplexing system. In PDGSIP, a collection of pilot patterns are firstly obtained and then pilot patterns having large mutual coherence are replaced with new ones generated with optimal pilot patterns. TPDGSIP directly produces new pilot patterns based on GSIP to fully exploit the pilot distance of the obtained pilot pattern as soon as one pilot pattern is obtained. Simulation results have shown that, the proposed pilot pattern design schemes are able to obtain the best pilot patterns in comparison to existing methods from the perspective of mutual coherence. Channel estimation performance using pilot patterns designed by proposed schemes precedes that using pilot patterns designed by existing schemes in terms of normalized mean square error and bit error rate.     

WCDMA中一种利用查表LMS算法的自适应阵

本文针对WCDMA中上行链路存在导频信道的特点,并结合变步长LMS算法的优点,提出了一种查表LMS波束形成算法。该算法利用导频信号作为空间波束形成的参考信号,把误差范围和相应的步长存储到列表中,在进行波束形成时所要采用的迭代步长直接在列表中查取。该算法的实现复杂度低,收敛速度快,运算量小。     

多径衰落信道中导引辅助二维扩频的导引功率优化

在多径衰落信道中,针对BPSK调制的广义二维扩频系统,该文分析了导引符号与数据符号的功率比对导引辅助相干解调的误码率性能的影响,在系统总的发射功率一定的条件下,优化了导引符号与数据符号的功率比。结果表明,分析结果与仿真结果相吻合,导引符号与数据符号功率比的最优值是由多径信道的信噪比、多普勒频移、多径时延、低通滤波器的特性等因素决定的。     

物联网技术助力集装箱多式联运初探

2013年9月29日,中国(上海)自由贸易试验区正式揭幕,对于从事进出口贸易的企业来说是一个非常好的契机,而对于集装箱运输行业来说,也提供了一次大力发展,与国外班轮公司竞争的机会。本文分析了集装箱多式联运的优点、自贸区为其带来的机会以及我国开展集装箱多式联运中的问题,初步探讨了如何利用物联网相关技术,结合集装箱多式联运的手段,来实现更低成本下的快速便捷物流。     

异频在室内覆盖中的应用

介绍了异频方案在室内覆盖中的应用,包括在异频覆盖情况下空闲切换的实现,伪导频的配置方式,并介绍了异频待机、室内异频分层覆盖的方案及相关案例。     

工业企业新产品试制过程管理的研究

本文从提高微观经济效益的角度,研究了工业企业新产品试制过程管理的问题。文中指出：企业新产品试制过程管理是企业管理系统的一个重要组成部分,要运用现代化手段管理新产品试制过程。     

Approximating the Outage Probability of the Pilot Channel for IS‐95‐Based Cellular CDMA Systems in the Soft Handover Region

This letter presents an approximation of the outage probability of the pilot channel that can be used for CDMA cell planning. The approximation can determine system parameters for soft handover in IS‐95‐based cellular CDMA downlink design. Computer simulations show that our analytical results agree with empirical results.     

Distribution of microbes in supercritical CO2 extraction of sea buckthorn (Hippopha? rhamnoides) oils

 The distribution of vegetative microbial cells and their spores in a supercritical CO₂ extraction process was studied. The seed and flesh/skin fractions of the press residue of sea buckthorn berries (Hippopha? rhamnoides) from a juice factory were used as raw materials. A pilot-scale extraction plant was operated at 30 MPa at temperatures of 40 and 60°C. The number of yeasts, moulds and bacteria in the pulp/skin fraction, in the extraction residues, in the extracted oils as well as in the water phases separated from the extracted oils was estimated by the spread plate technique. The microbial content of the flesh/skin material was increased in some extractions by the addition of bacterial spores. In general, the extraction process led to a decrease in the bacterial count of the extracted material, whereas no microbial growth was detected in the oils extracted or in the water phases separated from them. Neither yeasts nor moulds were found in any samples after the extraction process. The microbial status of seed oil and flesh/skin oil obtained by industrial-scale CO₂ extraction at 40°C and at 30 MPa before and after gelatine encapsulation remained unchanged. This proves that supercritical CO₂ can be used to manufacture edible oil products free of living micro-organisms and their spores. Received: 14 May 1996     

啤酒酿造酵母原生质体融合株GR5的中试

报道了啤酒酵母原生质体融合株GR5的中试结果。融合株GR5的凝絮性较强 (本斯值为 2 .7) ,以12°Bx麦芽汁为培养基 ,用 5 0 0L发酵罐在 12℃下发酵 ,发酵至第 8d菌株GR5的发酵度为 6 9.2 % ,发酵液中的双乙酰含量为 0 .0 4 98mg/L、乙醛含量为 6 .34mg/L ,总高级醇含量为 74 .4mg/L ,该菌株生产的啤酒 ,口感柔和、协调 ,略带酯香味。融合株GR5的遗传性稳定 ,是一株具有工业应用前景的啤酒酿造酵母菌株