Axcera Demonstrating Echo-Canceling Repeater at IBC2007

Low-power transmitters can be an important part of a single-frequency network, but the cost of providing a signal to many low-power transmitters by microwave or fiber may be prohibitive. On-channel boosters solve this problem, but it is often difficult to achieve sufficient isolation between the transmit antenna and the receive antenna.

Axcera will demonstrate its solution to this problem at IBC2007—an echo-canceling repeater based on a low-power version of its Innovator LX DVB-T/DVB-H transmitter, introduced at NAB2007. Echo cancellation suppresses the delayed signal received from the output of the repeater, allowing the booster to function with less isolation between the antennas and providing greater system stability.

Axcera said overall insertion delay is as low as six microseconds. The repeater being shown only works on the DVB-T and DVB-H formats, but the techniques should also be applicable to ATSC repeaters. An ATSC on-channel booster using an echo cancellation system designed at ETRI in South Korea was shown by Hi-Wave at NAB2006.

Axcera said the Innovator transmitter line features a web browser/SNMP interface and is available at power levels ranging from 5 to 1850 W. Axcera will also be showing its Innovator HX line of high power solid state transmitters and its 5720 series MMDS transmitter at IBC2007.

Doug Lung

Doug Lung is one of America's foremost authorities on broadcast RF technology. As vice president of Broadcast Technology for NBCUniversal Local, H. Douglas Lung leads NBC and Telemundo-owned stations’ RF and transmission affairs, including microwave, radars, satellite uplinks, and FCC technical filings. Beginning his career in 1976 at KSCI in Los Angeles, Lung has nearly 50 years of experience in broadcast television engineering. Beginning in 1985, he led the engineering department for what was to become the Telemundo network and station group, assisting in the design, construction and installation of the company’s broadcast and cable facilities. Other projects include work on the launch of Hawaii’s first UHF TV station, the rollout and testing of the ATSC mobile-handheld standard, and software development related to the incentive auction TV spectrum repack.
A longtime columnist for TV Technology, Doug is also a regular contributor to IEEE Broadcast Technology. He is the recipient of the 2023 NAB Television Engineering Award. He also received a Tech Leadership Award from TV Tech publisher Future plc in 2021 and is a member of the IEEE Broadcast Technology Society and the Society of Broadcast Engineers.