Spread-spectrum

FLL、PLL、DLL的设计与比较,在扩频通信系统中这三种环路就是关键。(FLL, PLL, DLL design and comparison, in the spread spectrum communication system in these three loops is the key.)

利用维特比算法解调GMSK信号 维特比算法的一个用处(Viterbi algorithm using GMSK signal demodulation Viterbi algorithm is a useful)

多径时变（多普勒效应）信道的文献讲解和相关仿真程序。(Multipath literature to explain the change (Doppler effect) channel and related simulation program.)

ZTEWelink Wireless Module Driver User Guide for WinCE-V1.2

航空航天通信技术一般采用模拟通信的频率调制和数字通信的移相键控调制方法。这有利于充分应用信道带宽和能源。频率调制是在一定程度上改变载波或副载波的频率来传输信息的调制方法。移相键控调制是利用载波或副载波的相位跳变来传输信息的调制方法。移相键控又分二相移相键控、四相移相键控和多相移相键控，其中以四相移相键控和八相移相键控调制方法的效率较高(Aerospace communications technology commonly used analog communication of frequency modulation and the digital communication phase shift keying modulation method. This is helpful for making full use of channel bandwidth and energy. Frequency modulation is changed to some extent carrier or subcarrier frequency to transmit information modulation method. Phase shift keying modulation is the use of carrier or subcarrier phase jump to transmit information modulation method. Phase shift keying and binary phase shift keying, four phase shift keying and multiple phase shift keying, of which four phase shift keying and eight phase shift keying modulation method of high efficiency )

By building the generalized Sigmoid function relationship between normalized step-size and the power of error signal, a novel variable step-size NLMS algorithm is proposed. It is proved that the step-size of NPVSS-NLMS changes as the new algorithm does when A=σv -m and B=2. The physical meanings of the parameters in this algorithm are explored. The theoretical analysis illustrate that this algorithm combine the virtues of NPVSS-NLMS and Sigmoid function, and it leads to faster convergence rate and lower final misalignment. The computer simulation results support the theoretical analysis.

恒频恒压(CVCF)逆变电源的输出电压波形质量是衡量其性能的重要指标之一。文章采用一种重复控制和双闭环控制相结合的电压波形控制策略，以重复控制器提高逆变电源输出电压的稳态精度，减小总谐波畸变率；以双闭环控制器达到较快的动态响应速度。该方案在一台采用TMS320F240 DSP控制芯片的50 Hz三相PWM逆变器上得到验证。(Constant voltage constant frequency (CVCF) Inverter output voltage waveform quality is an important measure of its performance indicators. Paper using a repetitive control and the combination of double closed loop control voltage waveform control strategy to improve the repetitive controller output voltage inverter steady-state accuracy and reduce total harmonic distortion to achieve a faster dual-loop controller dynamic response speed. The program uses TMS320F240 DSP in a 50 Hz phase control chip PWM inverter has been to verify.)

comparaison of photovoltaic mppt algorithms

仿真图是速度、距离、幅度三维图像，插值与拟合的matlab实现，计算两个矩阵之间的欧氏距离。( FIG simulation speed, distance, amplitude three-dimensional image, Interpolation and fitting matlab implementation, Calculation of the Euclidean distance between the two matrices.)

说明：  对当前通信信号中常用的数字调相信号BPSK、QPSK、1／4一QPSK、8PSK的调制识别问题，提出了一种基于信号差分高阶累积量的识剐算法。该算法分两个层次进行调制识别，首先利用信号的四阶累积量特征对BPSK、QPSK和{1／4一QPSK、8PSK}信号进行识别，然后再利用信号差分的四阶和八阶累积量特征对1/4-QPSK、8PSK信号进行识别。从理论上分析了的该算法的有效性，并通过计算机仿真验证了算法具有良好的性能。(A recognition algorithm based on differential high-order cumulant is proposed for the modulation recognition problems of BPSK, QPSK, 1/4-QPSK and 8PSK, which are commonly used in current communication signals. The algorithm is divided into two levels for modulation recognition. Firstly, BPSK, QPSK and {1/4-QPSK, 8PSK} signals are identified by using the fourth-order cumulant characteristics of signals, and then 1/4-QPSK and 8PSK signals are identified by using the fourth-order cumulant and eighth-order cumulant characteristics of signal difference. The validity of the algorithm is analyzed theoretically, and the good performance of the algorithm is verified by computer simulation.)