chatroom

opnet simulation of random access in CDMA network

说明：  LDPC码的mackay构造法，PEG构造法，QC-LDPC构造，SPA译码算法(LDPC codes are constructed by Mackay, PEG, QC-LDPC and Spa decoding algorithms)

说明：  51单片机，通过人体红外热释电模块检测人数，并计数。(51 single chip computer, through the human body infrared pyroelectric module to detect the number of people, and count.)

水声声线仿真，基于射线模型。文章包含仿真条件和说明。文章附件为程序。(Underwater acoustic line simulation, based on the ray model. The article contains simulation conditions and instructions. The article appendix is the procedure.)

基于互相关函数，采用求和广义互相关函数(summed-GCC)法用于机器人系统平台。由于采用不同的映射函数(mapping functions)，GCC法在该平台下，只需三个麦克风即可进行三维定位，突破了基于TDOA法进行三维声源定位最少需4个麦克风的限制(Based on cross-correlation function, using generalized cross-correlation function sum (summed-GCC) method for the robot system platform. Because of using different mapping function (mapping functions), GCC method in the platform, the only three to three-dimensional microphone positioning, a breakthrough TDOA method based on three-dimensional sound localization will take at least four microphone restrictions)

频谱感知，生成采样频率，进行能量检测，采用matlab算法(Spectrum sensing, generation of sampling frequency, energy detection, using matlab algorithm)

希尔伯特变换测试，使用希尔伯特变换对信号处理，相位偏移90°(The Hilbert transform test uses Hilbert transform to process the signal with a phase shift of 90 degrees)

说明：  LDPC的matlab仿真，使用BP算法，在BPSK调制信道下仿真(Matlab simulation of LDPC, using BP algorithm, simulation under BPSK modulation channel)

802.11 Wireless Networks

模拟圆形阵列天线方向图，画二维天线方向图；(Simulation circular array antenna direction map, drawing two-dimensional antenna direction pattern;)