ofdm

说明：  大规模MIMO中采用天线选择来降低系统复杂度和成本，其中包括最优天线选择和递减天线选择，快速天线选择和基于范数的天线选择算法。(Antenna selection is used in large-scale MIMO to reduce system complexity and cost, including optimal antenna selection and decreasing antenna selection, fast antenna selection and antenna selection algorithm based on norm.)

说明：  仿真多种调制信号,包括AM FM PSK QAM等(Simulate a variety of modulation signals, including AM FM PSK QAM, etc)

BPSK调制在高斯信道下的性能，误比特率和信噪比的曲线(BPSK modulation performance under gaussian channel, signal to noise ratio and bit error rate curve )

optimal coverage problem of wireless sensor network

HLP A+ Modbus 标准通讯协议格式，上位机发送数据格式，正确时变频器返回数据格式(This bit will be set to logic 1 when the receive buffer has been read and contains no new information. If there is new information available in the receive buffer that has not been read, this bit will return to logic 0. RXBMT = 1 when in Master Mode.)

OFDM（正交频分复用）系统以其抗多径衰落和较高的频带利用率，得到了众多领域的广泛应用。本文就OFDM系统中关键技术之一的信道估计技术进行了介绍。并分别叙述了OFDM系统和信道估计的意义，归纳了信道估计的分类，最后介绍了MMSE、LS及其改进信道估计算法并仿真出结果。(OFDM（orthogonal frequency division multiplexing) has been widely used in many areas for its good resistance to multipath fading and high bandwidth efficiency.In this paper,channel estimation,which is one of the key technologies in OFDM systems,were introduced. Then we discuss the significance of the channel estimation and the classification of channel estimation.Finally,we study the algorithms of channel estimation such as MMSE,LS and LMMSE,and further get the simulation results. )

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.)

说明：  基于空间调制的matlab代码，可完整运行(Matlab code of wireless communication system based on spatial modulation)

LDPC的矩阵生成，准循环码矩阵的生成，采用PEG算法生成，使用块矩阵方法(produce QC-LDPC matrix)

Modbus协议及Modbus RTU的C51编程(Modbus RTU Modbus protocol and the C51 programming)