Looking back at 2013, I would rate the availability of low-cost, high-performance software-defined radios and high-power solid-state UHF TV transmitters that come close to matching the efficiency of MSDC/ESC IOT transmitters as the top stories of the year in the RF industry.
As I reported last August, there are now at least three affordable software defined radios available. These radios have the ability to transmit as well as receive and using GNURadio software manufacturers, broadcasters and even individual hackers can experiment with new modulation and coding methods. The more expensive boards even support MIMO. See the paper Soft-DVB: A Fully-Software GNURadio-based ETSI DVB-T Modulator to learn how an Ettus USRP SDR was programmed to transmit a DVB-T signal to a receiver.
It’s difficult for broadcasters to change transmission methods primarily because viewers with legacy receivers will no longer be able to see the broadcasts. Currently the cost (both in money and power) of building a software-defined TV set or portable device makes it impractical, but as the technology improves the concept of a “universal receiver” may change that. In December I reported Orca Announces Multi-Standard TV Receiver IC for Tablets – Chip would receive any broadcast television standard.
In 2014 I hope to see more examples of software-configurable or software-defined receiver/demodulator chips for consumer devices. These could help ease the transition to the next generation broadcast platform. The ATSC 3.0 physical layer proposal from Coherent Logix and Sinclair Broadcast Group specifically targets the concept of a software-defined radio technology. See my article ATSC Receives 3.0 Physical Layer Proposals – Submissions offer wide range of technologies for more details and links.
Software-defined exciters for TV transmitters are available now--many exciters can be converted to different standards simply by uploading new firmware. The top news in TV transmitters this year was completion of the first installations of high-power UHF transmitters using Doherty modulation. I reported on the new transmitters in my NAB 2013 Show Observations.
At the 2013 NAB Show we saw Doherty transmitters in different stages of development from Comark, Hitachi (Linear), Rohde and Schwarz, and Screen Services. This year I had a chance to work with Rohde and Schwarz THU9 Doherty amplifier transmitters installed at KBLR television in Las Vegas, Nev. (these were 20 kW transmitter and this model was on display at the NAB Show). and also a 40 kW THU9 at WWSI television in Waterford, N.J. After seeing how well these transmitters performed, I wonder how many MSDC/ESC-IOT based transmitters will be sold in 2014 and beyond, even if they are a bit less expensive. The measured plant efficiency of the THU9 at WWSI was within two percent of the measured plant efficiency of a dual cabinet MSDC transmitter. I'll have more on this transmitter in an RF Technology column in 2014.
The FCC’s threat to require TV stations to change channels sometime in the next few years has caused many broadcasters to postpone upgrading facilities. This has hurt broadcast equipment manufacturers, at least in the U.S. market, and led to ownership changes at some of the top broadcast transmission equipment manufacturers in this country.
In late 2012 the senior management team at Thomson Broadcast U.S. completed a buyout of the company and renamed it Comark. Harris Corp. sold the Harris Broadcast division to an investment firm in Dec. 2012. And also in 2013, SPX decided there wasn't enough business in broadcast antenna manufacturing and soon after the NAB Show announced that it would shut down its Dielectric division. It came as a surprise to SPX that there was interest in buying the company and continuing the Dielectric line. Fortunately, for the many broadcasters depending on Dielectric antennas, Sinclair Broadcast Group, through its Acrodyne Services division, purchased Dielectric and was able to retain key management and engineering talent.
In 2014 these companies and other manufacturers of TV transmission equipment will face the challenge of finding money to invest in developing products such as new high-efficiency solid-state UHF TV transmitters and improved broadband antennas in order to be ready for the deluge of orders expected after the final FCC repacking plan is confirmed. Limited sales of new transmitters and antennas are expected in the interim. We should get an idea of how well manufacturers are handling this problem at the 2014 NAB Show.
Doug Lung is one of America's foremost authorities on broadcast RF technology. He has been with NBC since 1985 and is currently vice president of broadcast technology for NBC/Telemundo stations.
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