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December 19, 2011
Dennis Wharton
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Lab Tests Show Improved Performance Using Unequal Digital Sidebands for FM-Band HD Radio Signals

NAB FASTROAD-funded project characterizes improvement for closely-spaced scenarios

WASHINGTON, DC - NAB FASTROAD today announced the release of a report on laboratory testing of HD Radio asymmetric sideband technology for FM-band digital radio. This work was undertaken by iBiquity Digital Corporation, developers of the HD Radio IBOC system used by U.S. broadcasters to transition to digital radio, and was co-funded by iBiquity and NAB FASTROAD.

The report, entitled "HD Radioâ„¢ Asymmetric Sideband Laboratory Test Report," characterizes improvement in digital signal-to-noise ratio (SNR) that can be realized with the use of asymmetric (unequal) IBOC transmission power. This new transmission method affords broadcasters the ability to mitigate potential first-adjacent digital-to-analog interference by allowing independent adjustment of upper and lower IBOC digital sideband levels, maximizing the digital signal coverage area as a result.

NAB FASTROAD released a report on field testing of asymmetric sideband technology in February of this year, describing tests done at Greater Media station WKLB, located in the Boston, MA market. On November 1, 2011 the FCC issued a Public Notice requesting comment whether FM digital radio broadcasters should be authorized to use asymmetric digital sideband power on a voluntary basis.

The full text of this report and information on the NAB FASTROAD technology advocacy program are available at Inquiries on these results are encouraged - please contact NAB Technology Senior Director, Advanced Engineering David Layer at

NAB FASTROAD (Flexible Advanced Services for Television & Radio On All Devices) is the technology advocacy program of the National Association of Broadcasters. The overall mission of the FASTROAD program is to seek and facilitate development and commercialization of new technologies that can be exploited by broadcasters using radio and television broadcast spectrum.

About NAB
The National Association of Broadcasters is the premier advocacy association for America's broadcasters. NAB advances radio and television interests in legislative, regulatory and public affairs. Through advocacy, education and innovation, NAB enables broadcasters to best serve their communities, strengthen their businesses and seize new opportunities in the digital age. Learn more at

About iBiquity Digital
iBiquity Digital Corporation is the developer of HD Radio Technology, which is fueling the digital radio revolution in the United States and around the world. The digital technology enables broadcasters to offer new and unique FM content via HD2/HD3 channels, crystal-clear sound and data services on both the AM and FM bands - all free, with no subscription fee. Leading broadcasters, consumer electronics manufacturers, automakers and retailers are committed to HD Radio Technology. iBiquity Digital is a privately held company with operations in Columbia, MD, Auburn Hills, MI, and Basking Ridge, NJ. For more information, please visit and


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