Author: Pentti Jaatinen

Name of the thesis: Interference caused by Digital Audio Broadcasting to radio equipment and radio systems, which frequency is 174-240 MHz

Date: 22.10.1999
Number of pages: 94

Faculty: Electrical and telecommunication engineering

Professorship: S-72 Telecommunication engineering

Supervisor: Prof. Sven-Gustav Häggman

Instructor: M. Sc. Kari Kangas

Finnish Broadcasting Company Ltd (YLE) began the regular digital radio broadcasting in Finland on 12th October 1998, it became necessary to investigate signal propagation and the interference caused by DAB in the frequency band 174...240 MHz. There are also other radio spectra users in that frequency band: VHF-television, cabletelevision, radio datamodems, safety phones, dog radars etc.

In this thesis the ITU-R radio wave propagation model is extended to range shorter than 10 km. Also it is investigated how the Okumura-Hata - propagation model can be adapted to calculate the field strength of DAB signals. These two models are compared to each other and also to the model developed by Tuure Ikäheimonen in his Master's Thesis 1997.

The main concern has been the possible interference caused by DAB to the radio equipment and radio systems mentioned above. The interference to cable television systems, safety phones, radio datamodems and dog radars is tested in the DAB-field.

The extended ITU-R curves or Okumura-Hata model can be used in evaluating DAB-signal interference in the transmitter close range.