通信系统

A small scale digital trunking communication system based on the spread spectrum technology was presented.

介绍了一种基于扩频技术的全双工通信小型集群通信系统。

It is possible to communicate among some communication systems by Software Radio, and it appeases the development requirement of modern communication system.

软件无线电的出现为各种通信系统互连互通的实现提供了可能，满足了现代通信发展的需要。

When cognitive radio coexists with primary system, it mustn't cause excessive interference to legacy users.

当认知无线电网络与传统的通信网络共存时，首先要保证不会对传统的通信系统产生有害的干扰。

For high performance,concatenated coding is often used in the data communication system.

在数字通信系统中，为了保证通信的高质量，在信道中采用了各种编码来降低误码率。

It proved that the model can be used to analyze the propagation characteristics, optimize the modulation and coding schemes and performance simulation of the HAPS communication systems.

证明该模型可用于高空平台站通信电波传播特性的分析、调制及编码方案的优化和通信系统性能仿真等方面的研究。

cyclic redundancy check code is a very important cyclic code,the coding and decoding methods are simple,easy to realize.it is strong to detect error,the probability of misjudging is nearly zero.it is a method with extremely high efficiency in controlling errors,which can fulfill the requirement of reliable information transmission in communication systems.it has got very extensive application in observing and controlling and data communication.this paper introduces the encoding and decoding principle of crc in detail,analyzes the feasibility of crc by dsp,and gives out the design proposal and flow chart according to the principle,which is very useful in applications.

摘 要：循环冗余校验码是一种重要的循环码，编码和解码方法简单，容易实现，检错能力强，误判概率几乎为零，是一种效率极高的差错控制方法，可以满足通信系统可靠传送信息的要求，在测控及数据通信中得到了非常广泛的应用。详细介绍了循环冗余校验的编解码原理，分析了用dsp实现crc的合理性，最后给出了根据校验原理实现的设计思想及流程图，具有一定的实用价值。

An effective method is presented in this paper to deal with the difficulties of carrier tracking and chip synchronization in spread spectrum communications with high processing gain.

针对高增益的扩频通信系统中载波恢复跟踪和码片同步的难点，提出了一种有效的方法，并基于TI公司的数字信号处理器TMS 32 0F 2 4 0 ，对高增益的扩频通信的关键技术进行了实现。

This invention discloses a duplexer and a multiplexer of the communication system and a method to realize them on a PCB circuit, which applies a 3db bridge and a low pass filter to constitute a hopstreet duplexer without waste band channels, in which, the signals are shunted and combined by the design of the circuit structure and power distribution of the 3-db bridge and phase offset function, the band filter of the low pass filter and the reflection function of a stopband to make up of a costless duplexer in theory to merge the two channels of different frequencies and reduce loss to increase volume and working bandwidth, then a multiplexer is formed by cascading multiple duplexers.

本发明涉及通信设备，公开了一种通信系统双工器和多工器以及双工多工方法，使得双工器和多工器能够在PCB电路上实现，并且体积小、损耗小、成本低、容量大。本发明中，采用三分贝电桥、低通滤波器构成无损耗频带信道合路的双工器，其中通过电路结构的设计并利用三分贝电桥的功率分配和相位偏移功能将各路信号进行分路和组合，利用低通滤波器的频带滤波和阻带反射功能联合三分贝电桥构造一个理论无耗的双工器，使两路不同频率的信道合路，降低的损耗、提高容量和工作带宽。通过多个上述双工器的级联构成多工器。

This paper introduces the design and imp lementation of an asynchronous-communications system which emp loys TL16C554A as its core hardware, including the selection of the asynchronous-communications elements, the circuitry design, the temporal logic and software realization.

根据微型无人机飞控计算机与外围多个设备进行通信的需要，介绍了由 TL16C554A 芯片组成的多路异步串行通信系统的设计与实现，包括扩展异步串行接口的方案选择、硬件电路设计、时序逻辑实现及软件实现。

In order to provide more convenience to the consumers, the research and implementation of multimode wireless communication systems became a new focus of the development on wireless data communication system.

为了给消费者提供更大的便利，多模无线通信系统的研究与实现成为无线数据通信技术发展中的一个新的亮点。

On the other hand, the more important thing is because the urban housing is a kind of heterogeneity products.

另一方面，更重要的是由于城市住房是一种异质性产品。

Climate histogram is the fall that collects place measure calm value, cent serves as cross axle for a few equal interval, the area that the frequency that the value appears according to place is accumulated and becomes will be determined inside each interval, discharge the graph that rise with post, also be called histogram.

气候直方图是将所收集的降水量测定值，分为几个相等的区间作为横轴，并将各区间内所测定值依所出现的次数累积而成的面积，用柱子排起来的图形，也叫做柱状图。