DVB-T / OFDM

Introduction

Digital multimedia applications as they are getting common lately create an ever increasing demand for broad band communication systems. Although the technical requirements for related products are very high the solutions must be cheap to implement since we are basically talking about consumer products.

Whereas for the satellite channel and for the cable channel such cost-efficient solutions already exist for the terrestrial link (i.e. classical TV broadcasting) the requirements are so high that the 'standard' solutions are no longer feasible or lead to sub optimal results. Orthogonal Frequency Division Multiplexing (OFDM) is a method that allows to transmit high data rates over extremely hostile channels at a comparable low complexity. OFDM has been chosen as the transmission method for the European radio (DAB) and TV (DVB-T) standard. Due to its numerous advantages it is under Discussion for future broadband application such as wireless ATM as well.

The OFDM project at the ISS is concerned with the development and evaluation of receiver structures for OFDM. Whereas so far we have focused on the broadcasting scenario attention now is switching to other applications including wireless ATM and fourth generation transmission techniques.

On this web-site we will briefly describe the general problem of multipath channels and introduce the multicarrier approach. We present the general structure of a receiver for DVB-T and discuss its performance.

• OFDM and the orthogonality principle
• An OFDM receiver for DVB-T