COGEU FP 7 ICT - 2009 . 1 . 1 COgnitive radio systems for efficient sharing of TV white spaces in EUropean context D 4 . 3 Testbed for coexistence evaluation

This Deliverable D4.3 describes the test set-ups, the wanted signals and the interference signals that are used for the measurements in the process of coexistence evaluation between DVB-T and White Spaces Devices. Keyword list: TV White Space Device, DVB-T receiver, interference, coexistence COGEU D4.3 – Testbed for coexistence evaluation Page 2 of 33 Executive Summary This Deliverable D4.3 contains a description of the COGEU testbed used for the evaluation of the conditions under which DVB-T receivers and White Space Devices (WSDs) can co-exist in the UHF TV band. The testbed for coexistence evaluation as it is described in this Deliverable D4.3 is a combination of test set-ups for testing of DVB-T receivers and TV White Space Devices (WSDs). It is designed to fulfil two requirements: 1. It assembles all necessary components for the evaluation of interference caused by White Space Devices and effecting DVB-T receivers; 2. For the opposite direction of interference, i.e. from DVB-T signal into WSDs, it also provides the required components for signal generation and quality measurements. Regarding the first requirement, it should be noted that the interference caused by WSDs and effecting DVB-T receivers is not limited to co-channel interference. It also considers the interference caused by WSDs operating in adjacent channels or in channels with a significant distance (in the frequency domain) to the channel occupied by the DVB-T signal. For the tests, a DVB-T signal from a signal generator, applied to a channel simulator in accordance to the transmission channel type, is input to a DVB-T receiver. An interfering signal in an adjacent or another channel, with variable power level, is added to the wanted signal. Wanted and unwanted signals are combined in the RF domain. The interfering signal power level is increased until the DVB-T signal reception is disturbed. The test set-up that addresses the second requirement, can also be used to verify the proper working of WSDs in the UHF band, i.e. to measure in which way WSDs are susceptible to interference from DVB-T transmissions. Specialized software drivers have been developed in order to allow the communication with the hardware parts of the testbed. Using the driver software as a base, a framework has been developed to effectively control the entire system. Initials results suggest that a WiFi (5 MHz) interferer operating in the same frequency as a DVB-T service, can cause interference noticeable to the image quality, if the CIR (WiFi is considered as the interference source in this case) is 11 dB or less. COGEU D4.3 – Testbed for coexistence evaluation Page 3 of 33 Table of