通信系统

For the demand of low orbit satellite communication system requiring, designs the quadrifilar helix antenna was designed.

根据低轨道小卫星通信系统对天线的要求，文章对四臂螺旋天线进行研究。

A car in which policemen cruise the streets; equipped with radiotelephonic communications to headquarters.

警察巡逻街道的车；装备有和总部联系的声讯通信系统。

The first step is reviewing conventional methods of digital beam forming, including WINER method, Steepest-Descent method, LMS, RLS etc. Then , recent digital beam forming methods in the DS-CDMA mobile telecommunications systems are studied, including the algorithm based on least-squares despread respread Multi-Target array, least-squares Despread Respread Multi-Target Constant Modulus Array , Pilot bit LMS-DRMTA algorithm etc.

本文首先简介传统的DBF算法，包括维纳算法、最陡下降算法、最小均方算法、递归最小二乘算法等；然后介绍基于DS-CDMA移动通信系统的DBF算法，包括LS-DRMTA、LS-DRMTCMA导频LMS-DRMTA算法等；最后给出各种算法的仿真结果及分析。

Acquisition algorithm for synchronization is a key technology in SESS system .

编码序列的同步捕获是自编码扩频通信系统中的关键技术。

The simulation results show the acquisitionmethod of SESS system can be just as reliable as the conventional DSSS systems.

仿真结果表明，自编码直扩通信系统的编码捕获性能具有可行性。

To con-struct mo bile tele com system with WCD MA will be the best choice from either the con sideration of the rela-tions between fre quen cy resources and sys tem,or the consid era tion of3G main system mode selection,or the con sideration of the utiliza tion of un-balanced fre quency band resourc...

无论从基于频率资源与制式关系的考虑，基于选择3G主流制式的考虑，还是从基于利用非对称频段资源、采用TD-SCDMA混合组网的考虑，对新的运营商来说，采用WCDMA来建设移动通信系统都是必要和有利的选择。

An adaptive conjugate gradient algorithm based on subband decompsition structure was proposed for acoustic echo cancellation in communication systems.

针对通信系统中的声学回声干扰问题，研究了一种快速收敛和有效的自适应回声抵消算法。

In the first chapter of the paper, there are the background materials introduced about Beijing Xinxin Company and conceiving origin of IP trunked radio system.

在本文的第一章节介绍了北京新信公司的基本情况以及 IP 集群通信系统构思产生的来源。

In the third chapter, there is a technology option about IP trunked radio system in technology aspect, economic aspect and venture aspect.

第三章对 IP 集群通信系统在技术、经济和风险方面进行了技术评价。

MPT1327 is an open signalling standard of trunked private land mobile radio system.

MPT1327 是专用信令信道集群移动通信系统的一种公开的典型信令。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。