数字通信系统仿真

无线信道建模一直以来都很复杂，而且不同场景下的模型差异较大，这是一本专门讲解无线信道建模方法的书籍配套的matlab例程(Channel modeling has been very complex, and the model under different scenarios are quite different, which is the one devoted to channel modeling method books matching matlab routines)

针对MIMO-OFDM系统中期望最大化(EM)信道估计算法在高信噪比(SNR)下带来的误差地板(EF)现象,且OFDM符号的数据传输效率随发射天线数的增加而明显降低,提出一种改进的高效EM信道估计算法。该算法首先引入一种准确的等效信号模型并推导出一种修正的EM算法,改善了EM算法在高SNR下的性能 在多个OFDM间利用相位正交导频序列来提高数据传输效率,同时进行联合信道估计以提高估计性能。仿真实验验证了所提算法具有更高的信道估计性能和更高的数据传输效率。(For multiple-input multiple-output with orthogonal frequency division multiplexing(MIMO-OFDM) systems,the error floor(EF) phenomenon at high signal noise rate(SNR) was induced by the expectation maximum(EM) channel estimation algorithm.In addition,the data transmission efficiency was declined obviously with the increasing number of transmit antennas.According to these problems,an improved and efficient EM channel estimation algorithm was pro-posed.Firstly,an accurate and equivalent signal model was introduc...)

收发传真，浏览传真的程序(A program which receive、send and scan fax)

可以产出LDPC_802.16e码字，不同码长不同码率(creat LDPC_802.16e ldpc code)

labwindows CVI 8.0 下调试通过的gprs，建立过程和udp通讯。(with labwindows cvi8.0,gprs connection had been programmed,and udp test is ok )

说明：  ofdm的编码过程，用evm和比特率进行对比(The encoding process of OFDM is compared with EVM and bit rate)

自己需要给出坐标，GPS测距。主要是实现了基于maltab测距GPS测距原理(you should give coordinates, GPS ranging)

16QAM调制信号的GAD定时恢复，对定时恢复环路的验证和实现(Gardner Timing Recovery for 16QAM)

用c语言实现fft和iir滤波器的设计。可以和matlab中的函数fft,filter等效。(used language fft and IIR filter design. Matlab can and the function fft, filter equivalent.)

微波实验设计，设计波导滤波器和波导等功率分配器(Microwave experimental design, waveguide filter design and waveguide power divider etc.)