WCDMA基本原理教材,中兴公司培训教材。3G时代，学通信的要赶快赶上啊！...

an article about multi-path protocol for cognitive radio network.

We investigate the case of independent Rayleigh faded paths between antenna elements and find that with high probability extraordinary capacity is available. Compared to the baseline n = 1 case, which by Shannon’s classical formula scales as one more bit/cycle for every 3 dB of signaltonoise ratio (SNR) increase, remarkably withMEAs, the scaling is almost like n more bits/cycle for each 3 dB increase in SNR. To illustrate how great this capacity is, even for small n, take the cases n = 2, 4 and 16 at an average received SNR of 21 dB. For over 99 of the channels the capacity is about 7, 19 and 88 bits/cycle respectively, while if n = 1 there is only about 1.2 bit/cycle at the 99 level. For say a symbol rate equal to the channel bandwith, since it is the bits/symbol/dimension that is relevant for signal constellations, these higher capacities are not unreasonable. The 19 bits/cycle for n = 4 amounts to 4.75 bits/symbol/dimension while 88 bits/cycle for n = 16 amounts t

本程序实现了一个基本的基于2psk的误码率仿真程序，比较适合初学通信的人士学习。-This program realize a simulation based on Bpsk modulation, and it is suitable for any beginner of telecommunication

modbus协议-----51端程序的实现-modbus protocol----- 51-side programs to achieve

噪声对通信系统的影响试验程序 模仿各种噪声对不同通信系统的影响 具有很强的学习价值-noise on the communication system of testing procedures to imitate various noise on different communication systems with a strong influence of school Xi value

基于stm32开发平台的can总线通信，文件里有发送和接收源代码，适合学习stm32和can总线通信的朋友参考

蓝牙技术现在应用越来越多，通过这个程序可以学到基本的蓝牙通信原理。-bluetooth program code

MFC下CSocket编程例子,包含client和server端。-MFC under the CSocket programming examples, including client and server side.

this a book that learning serial programming-this is a book that learning serial programming

该代码是关于在linux平台下的网络编程，epoll模型，socket接受线程：C语言为了高并发所以选择了epoll。当程序启动的时候（g_net_update.c文件中main函数，会启动一个thread见函数create_accept_task）这个thread就处理一件事情，只管接收客户端的连接，当有连接进来的时候 通过epoll_ctl函数，把socket fd 加入到epoll里面去，epoll设置监听事件EPOLLIN | EPOLLET; 主要是监听的是加入到epoll中的socket是否可读(因为我的需求是客户端连上了server就会马上向server发送一份数据的)。其它的部分在主线程中处理。主线程：是一个无线循环，epoll_wait 函数相当于把客户端的连接从epoll中拿出来（因为我们监听的是EPOLLIN | EPOLLET）说明这个时候客户端有数据发送过来）。再通过recv_buffer_from_fd 函数把客户端发送过来的数据读出来。然后其他的一切就抛给线程池去处理。线程池：(代码中我会在池里面创建15个线程) 双向链表。加入线程就是在链表后面加一个链表项，链表的前面会一个一个被拿出来处理。主要是malloc 函数free函数，sem_wait函数sem_post的处理（sem_wait 会阻塞当值大于0是会减一，sem_post是值加一）。typedef void* (FUNC)(void arg, int index);是我们自定义的线程的逻辑处理部分，arg是参数，index是第几个线程处理(我们隐形的给每个线程都标了号)，例如代码中的respons_stb_info，更加具体可以看看代码里面是怎么实现的。聪明的你也可以改掉这块的内容改成动态线程池，当某个时刻的处理比较多的时候能够动态的增加线程，而不像我代码里面的是固定的。数据库连接池：按照我的需求在处理客户端请求数据的时候是要访问数据库的。就是一下子创建出一堆的数据连接。要访问数据库的时候先去数据库连接池中找出空闲的连接，具体可以看下代码。使用的时候可以参考下database_process.c文件（代码中数据库连接池和线程池中的个数是一样的）。