ofdm_simulation_with_matlab

程序使用了自相关性和互相关性较好的gold码作为扩频序列，直扩，扩频增益设置为31，模拟用户数为4(Program uses a self-correlation and cross-correlation of the better gold code as spreading sequence, direct expansion, spreading gain is set to 31 to simulate the number of users of 4)

信道为瑞利信道，S_D的距离为1米，三跳协作通信系统中S_R、R1_R1、S_D的距离均为1/3米。调制方式为BPSK,信噪比在-15dB-15dB间，接收端合并方式为ERC,迭代次数为1000(The channel is Rayleigh channel, the distance of S_D is 1 m, and the distance of S_R, R1, S_D in three-hop cooperative communication system is 1/3 M. The modulation mode is BPSK, the signal-to-noise ratio is between - 15dB and 15dB, the receiver merge mode is ERC, and the number of iterations is 1000.)

OFDM降低峰平比采用预失真技术，程序仿真了加入预失真技术后的星座图与未加预失真的比较。结果比较明显。采用QAM映射。(OFDM PAPR reducing the use of pre-distortion technology, process simulation technology to join the pre-distortion of the constellation diagram and the following not pre-distortion comparison. More obvious results.)

该程序可以实现多个客户端互相通讯，如同聊天室(Multiple clients can communicate with each other, just like chat rooms)

Improvement in Cognitive Radio

fpga时钟，是入门的基础；希望对大家有帮助！(fpga clock, is the entry of the base want to help you!)

衰落信道的仿真，包括瑞利，莱斯信道，还有分集接收等内容(Fading channel simulation, including the content of the Rayleigh and Rice channel, there is diversity reception)

MODBUS通信程序，仪表内部通讯用，RTU格式(MODBUS communication procedures, instrumentation, internal communications, RTU format)

说明：  设计一个数字低通滤波器，来近似一个理想数字滤波器(Design a digital low-pass filter to approximate an ideal digital filter)

正交编码方面的文章Coded Orthogonal Signaling(1993)(Coded Orthogonal Signaling(1993))