Grundig Digital Radio manual HD Radio Standards Activity, HD Radio AM and FM Receivers

DIGITAL RADIO GUIDE TERRESTRIAL TRANSMISSION SYSTEMS - HD RADIO

4.4.1HD Radio Standards Activity

Both the AM and FM HD Radio systems have received international endorsements as well as endorsements in the United States. The AM HD Radio system is included in Recommendation ITU-R BS.1514-1, adopted October 2002 where it is classified as the “IBOC DSB System.” The FM HD Radio system is included in Recommendation ITU-R BS.1114-4, adopted May 2003 where it is classified as “Digital System C.” In the United

States, the Federal Communications Commission (FCC) endorsed both the AM and FM HD Radio systems on October 10, 2002. 7 Moreover, the National Radio Systems Committee (NRSC), an industry standards setting body sponsored by the National

Association of Broadcasters and the Consumer Electronics Association, endorsed the FM HD Radio system in a report dated November 29, 20018 and the AM HD Radio system in a report dated April 6, 2002.9 The NRSC endorsement was an outgrowth of an extensive testing program of both the AM and FM HD Radio systems. The NRSC supervised independent testing of the HD Radio system in both the laboratory and in the field under a comprehensive set of conditions. The tests were designed to assess both the performance of the digital system as well as the compatibility of the digital system with existing analogue operations in the AM and FM bands. In the laboratory, the digital system was subjected to a range of conditions associated with typical broadcasts in the AM and FM band. For example, the FM system was tested in the presence of multiple forms of multipath interference as well as numerous examples of co-channel and adjacent channel interference. In the case of AM, the digital system was tested in the presence of impulse noise in addition to the typical co-channel and adjacent channel interference associated with the AM band.

Field tests were conducted using commercial AM and FM stations selected for their characteristics in terms of interference from adjacent channel stations as well as to represent a variety of antenna and implementation configurations. For both the laboratory and field tests, objective measurements were recorded and considered in the evaluation process. In addition, thousands of audio samples were produced and used to conduct an extensive subjective evaluation process. General population listeners were asked to rate a variety of sound samples from the laboratory and field tests to assess the real world response to the introduction of the HD Radio system. The test results demonstrated that the HD Radio system consistently outperformed existing analogue AM and FM radio. Moreover, the tests established that the introduction of the HD Radio system will not cause harmful interference to existing analogue broadcasts in the vast majority of cases. In those cases where new interference is expected to occur, it is expected that new interference will be most common in peripheral areas outside the core coverage areas of a station. The NRSC concluded that this minimal risk of additional

interference is more than outweighed by the improved audio quality and performance that the HD Radio system repeatedly demonstrated throughout the test programme.10

4.4.2HD Radio AM and FM Receivers

HD Radio receivers are inherently simpler and lower cost than new band receivers since much of the circuitry required for the digital signals is common to that used to process the

7Digital Audio Broadcasting Systems And Their Impact on the Terrestrial Radio Broadcast Service, MM Docket No. 99- 325, First Report and Order (October 10, 2002).

8DAB Subcommittee Evaluation of the iBiquity Digital Corporation IBOC System Part 1 – FM IBOC dated November 29, 2001 (“NRSC FM Report”).

9DAB Subcommittee Evaluation of the iBiquity Digital Corporation IBOC System Part 2 – AM IBOC dated April 6, 2002 (“NRSC AM Report”).

10See NRSC FM Report at 9; NRSC AM Report at 8.

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