gr-isdbt

Implementación de un receptor de ISDB-T abierto y para metrología bajo el paradigma de Radio Definida por Software

Project funded by the ‘Dirección Nacional de Telecomunicaciones y Servicios de Comunicación Audiovisual’ (DINATEL) through the ‘Agencia Nacional de Investigación e Innovación’ (ANII) (proyecto FST_1_2013_1_13179)

Universidad de la República

Pablo Belzarena
Pablo Flores Guridi
Gabriel Gómez Sena
Víctor Gonzalez Barbone
Federico “Larroca” La Rocca (responsible)

Abstract

The goal of the Software Defined Radio (SDR) technology is to implement as much as possible of a radio communication system by means of software. However, some hardware is still required: antennas and analog-to-digital converters are needed for tuning and sampling the signal that will we then digitally pocessed. We are particularly interested in three pieces of hardware, the USRP, the HackRF and the BladeRF. The three of them are open in some way, since the drivers and the codes used by the FPGAs in each device are openly avaliable and can be edited. Even the devices diagrams can be read. Moreover, they are somewhat accesible, as they cost some hundred of dollars. In their case, digital signal processing is performed by a PC. We used GNU Radio as framework to implement our blocks (which is both free and open source).

The project objective is to develop an open ISDB-T full_seg receiver based on SDR, especially designed for taking measurements in different points of the decoding chain. The idea, in addition to actually be able to watch TV and illustrate the different blocks of a typical receiver (we work in a University after all), is to offer a cheap alternative to DTV signal analyzers (which may cost from some to several many thousands of dollars). The receiver is implemented as an Out-of-tree module for GNU Radio, thus seamlessly integrating into it.

A DVB-T transceiver based on SDR was developed by Bogdan Diaconescu’s (BogdanDIA on git), see https://github.com/BogdanDIA/gr-dvbt, but we found no ISDB-T implementation. That is why we decided to make our own, but we took Diaconescu’s work as the starting point.

Resources

Our source code is on git. Please visit https://github.com/git-artes/gr-isdbt. Feel free to contact us, we are very interested in any kind of feedback (if you have a problem, the easiest and fastest way is to add a new issue in the git repository).

We have some recordings made with an USRP so you can test our code offline. You can download them from the following links (please refer to the README file for more info):

We got access to a playout, and we have tested all modes and several CP lengths. We are sharing some recordings here (please refer to the README file for more info):

The chosen parameters are part of the testing suite used in Uruguay for DTV compliance with ISDB-T. More information here.

Documents

As part of the project, the following documentation was prepared. However, most of it is in Spanish.