You can get many of MIMO-OFDM implementations using MATLAB in the book entitled "MIMO-OFDM Wireless Communications with MATLAB". See here: https://books.google.ie/books?id=6HwAoeuMr3kC&printsec=frontcover&dq=MIMO+OFDM+with+matlab+code+pilot&hl=en&sa=X&ved=0ahUKEwjJ0pbyk9fdAhWJAsAKHdOTAO4Q6AEIKTAA#v=onepage&q=MIMO%20OFDM%20with%20matlab%20code%20pilot&f=false
Hello Padmavathi, you can check this book about Massive MIMO systems "https://massivemimobook.com/wp/free-pdf/" and the corresponding simulation codes "https://massivemimobook.com/wp/simulation-code/"