相干光通信不同调制格式Matlab仿真

说明：  模拟调制识别各特征参数随信噪比变化曲线。信号的瞬时信息包括瞬时幅度、瞬时相位、瞬时频率及其不同角度的统计特征值，其中瞬时幅度、瞬时相位、瞬时频率是一个信号最基本的特征。（AM、DSB、SSB、VSB、FM、AM-FM）(Simulated Modulation Recognition Curve of Variation of Characteristic Parameters with Signal-to-Noise Ratio)

bpsk调制仿真，可直接用 1、数字调制方法 数字调制就是把数字基带信号的频谱搬移到高频处，形成适合在信道中传输的带通信号。基本的数字调制方式有振幅键控（ASK）、频移键控（FSK）、绝对相移键控（PSK）、相对（差分）相移键控（DPSK）。在接收端可以采用想干解调或非相干解调还原数字基带信号。 数字信号的传输方式分为基带传输和带通传输。然而，实际中的大多数信道（如）无线信道具有丰富的低频分量。为了使数字信号在带通信道中传输，必须用数字基带信号对载波进行调制，以使信号与信道的特性相匹配。(1, digital modulation method Digital modulation is the transfer of the spectrum of a digital baseband signal to a high frequency to form a bandpass signal suitable for transmission in the channel. The basic digital modulation methods are amplitude keying (ASK), frequency shift keying (FSK), absolute phase shift keying (PSK), and relative (differential) phase shift keying (DPSK). At the receiving end, the digital baseband signal can be restored by using dry demodulation or non-coherent demodulation. Digital signal transmission methods are divided into baseband transmission and bandpass transmission. However, most channels in practice, such as wireless channels, have rich low frequency components. In order for a digital signal to be transmitted in a band channel, the carrier must be modulated with a digital baseband signal to match the signal to the characteristics of the channel.)

DQPSK调制的程序,用Simulink的C函数实现()

VGA驱动及显示程序，用Verilog编写代码实现VGA的驱动和显示，并且提供了测试程序Testbench通过测试能得到正确的时序波形。(the source code for driving VGA and displaying the images,the testbench was offered.)

说明：  energy efficiency code for cognitive radio

说明：  SCMA log-MPA检测迭代次数对比(SCMA log-MPA detection)

MODBUS是工业领域通信协议的业界标准。这是周立功MODBUS的源码，适合应用和学习，需要的朋友可以看看。(MODBUS communication protocol is the industry standard in the industry. This is Zhou Ligong MODBUS source code, suitable for application and study, need friends can look at.)

说明：  5. 在三条径的瑞利信道中，对于直接序列扩频： (1) 请设计DS-CDMA一种具体的码分导引辅助的信道估计方法，接收机分别采用等均益合并、最大比合并。用Simulink进行仿真，画出比特信噪比与信道估计均方误差的关系曲线和比特信噪比与误码率的关系曲线。 (2) 设频率已经同步，请设计DS-CDMA一种具体的单停顿滑动相关时间同步方法，用Simulink进行仿真，画出比特信噪比与捕获概率的关系曲线。 (3) 设时间已经同步，请设计DS-CDMA一种具体的频率同步方法，用Simulink进行仿真，画出比特信噪比与频率同步误差的关系曲线。(5. In three-path Rayleigh channel, for direct sequence spread spectrum: (1) please design a specific code division navigation aided channel estimation method for ds-cdma, and adopt equal-beneficial combination and maximum ratio combination for receivers respectively.Simulink is used to simulate and draw the relationship curve between bit SNR and channel estimation mean square error and the relationship curve between bit SNR and bit error rate. (2) assuming that the frequency has been synchronized, please design a specific single-stop sliding correlation time synchronization method ds-cdma, Simulink simulation, draw the relationship between the bit SNR and the acquisition probability curve. (3) if the time has been synchronized, please design a specific frequency synchronization method ds-cdma, Simulink simulation, draw the relationship between the bit SNR and frequency synchronization error curve.)

GFSK调制通信系统误码率统计，非常有借鉴价值(GFSK modulation communication system bit error rate statistics, the very reference value)

说明：  STM32对接ESP8266的驱动,测试MQTT通讯和测试TCP通讯(STM32 TO ESP8266,test MQTT communication and test TCP communication)