Aggregate interference from white space devices into digital terrestrial television receivers

Abstract

The cognitive radio devices operating in the digital terrestrial television (DTT) frequency band, known as white space devices (WSDs), use the free DTT channels under the condition that they do not cause interference above the limit set by the regulator. In 2015, the UK regulatory authority, Office of Communications (Ofcom), published the first European regulation allowing WSD systems to operate in the DTT band. It defines a methodology to calculate the maximum WSD transmission power based on single-entry interference. It does not guarantee, however, that the co-channel aggregate interference produced by the WSDs operating in the same region satisfies the intersystem interference limit. In addition, to define the maximum intersystem interference, the Ofcom methodology does not use the same criterion as that used in DTT system planning for the intrasystem interference. This work develops a new methodology for calculating the WSD transmission powers that solve the problems identified in the Ofcom regulation. Based on this methodology, a new WSD admission procedure that guarantees the protection of the DTT receivers from the WSD aggregate interference is proposed. It is compared to two other admission procedures based on the Ofcom regulation and Electronic Communications Committee report 186, respectively.