Nowadays wireless technologies are the most widely used communication technologies around the world. Thanks to them, people, located far away, can exchange information even at high data transfers. This has been possible thanks to the continuous improvements, for more than two decades, in the involved technologies. In this project, it has been tried to implement the wireless communication standard currently being deployed around the world. This standard is known as Long Term Evolution (LTE). First of all, we will explain the structure of a radio frame, or how has been organised the data (signals and channels on the physical layer) transfers. Secondly, we will follow a hands-on approach to describe the steps to implement the downlink for both the eNodeB and the user terminal. In order to check our system we have performed several test using AWGN and real channels. The results from these test provides some insights about the quality of the implementation. Finally, a verified donwlink implementation will be introduced in Software-Defined Radio (SDR) technology with the objective to abstract the hardware issues and focus in the software improvement and optimization.