16QAM-OFDM

用于检测手机麦克风输入音量大小的DEMO(it s used to detect the volume of phones micphone)

介绍bch的基础知识，包括纠删码的编码和解码(Introduce the basic knowledge of bch, including the encoding and decoding of erasure codes)

通过具体的信道实例对比几种信道容量，绘出对数正态衰落、瑞利衰落、Nakagami衰落下确定的容量随平均接收信噪比变化的曲线。(The capacity of several channels is compared by a specific channel example, and the curve determined by the logarithmic normal fading, Rayleigh fading and Nakagami fading with the change of the average received signal to noise ratio (SNR) is drawn.)

说明：  ofdm qpsk 添加循环前缀 信道估计 补偿与均衡 信号星座图(OFDM QPSK add cyclic prefix channel estimation compensation and equalization signal constellation)

kd树，matlab源码 kd树，matlab源码(kdtree wiritten in matlab)

实现基于STBC的MIMO_OFDM通信系统在不同信噪比情况下接收端的误比特率的仿真。发射端包括基于基带调制、空时编码、导频插入、IFFT、串并合并以及添加循环前缀；接收端包括去除循环前缀、取出导频估计信道、FFT运算以及并串合并，空时解码等。仿真中采用QPSK、空时编码采用4*3的复正交空时编码矩阵。OFDM子载波数为100，每个子载波传输66个符号，每个符号2比特。IFFT长度为512个符号。发射天线为3个接收天线为2个。(The BER simulation of MIMO_OFDM communication system based on STBC under different SNR is realized. The transmitter includes baseband modulation, space-time coding, pilot insertion, IFFT, serial-parallel combination and adding cyclic prefix; the receiver includes removing cyclic prefix, extracting pilot estimation channel, FFT operation, parallel-serial combination, space-time decoding, etc. The complex orthogonal space-time coding matrix is used in QPSK and space time coding in 4*3. The number of OFDM subcarriers is 100, and each subcarrier transfers 66 symbols with 2 bits per symbol. IFFT is 512 symbols in length. The transmitting antenna is 3 receiving antennas, 2.)

说明：  实现Polar码编码译码，SC译码，简单实用，运行速度快(Polar MATLAB include encode and decode useful and simple)

说明：  51MODBUS从机程序源码希望对有用的人有用，，(51MODBUS,welcom to here,thank you very mouch.)

说明：  可以同时模拟多个GB28181摄像头。 用于GB28181平台的压力测试(Multiple gb28181 cameras can be simulated at the same time. Pressure test for gb28181 platform)

说明：  阐述了RS-485总线规范，描述了影响RS-485总线通信速率和通信可靠性的三个因素，同时提出 了相应的解决方法并讨论了总线负载能力和传输距离之间的具体关系。 (Described the RS-485 bus specification, describes the impact of RS-485 bus communication speed and communication reliability of the three factors, while the corresponding solutions presented and discussed the bus load capacity and the specific relationship between the transmission distance.)