实现基于STBC的MIMO_OFDM通信系统在不同信噪比情况下接收端的误比特率的仿真。发射端包括基于基带调制、空时编码、导频插入、IFFT、串并合并以及添加循环前缀；接收端包括去除循环前缀、取出导频估计信道、FFT运算以及并串合并，空时解码等。仿真中采用QPSK、空时编码采用4*3的复正交空时编码矩阵。OFDM子载波数为100，每个子载波传输66个符号，每个符号2比特。IFFT长度为512个符号。发射天线为3个接收天线为2个。(The BER simulation of MIMO_OFDM communication system based on STBC under different SNR is realized. The transmitter includes baseband modulation, space-time coding, pilot insertion, IFFT, serial-parallel combination and adding cyclic prefix; the receiver includes removing cyclic prefix, extracting pilot estimation channel, FFT operation, parallel-serial combination, space-time decoding, etc. The complex orthogonal space-time coding matrix is used in QPSK and space time coding in 4*3. The number of OFDM subcarriers is 100, and each subcarrier transfers 66 symbols with 2 bits per symbol. IFFT is 512 symbols in length. The transmitting antenna is 3 receiving antennas, 2.)