Link Research links the Ryder Cup links
By Ken Kerschbaumer
Next week s Ryder Cup
broadcast will break some new sports broadcast technology ground as up to nine
HD wireless transmission systems from Link Research will be used to transmit HD
material from the greens of the K Club in County
to viewers around the world.
It s the biggest use of our
systems at one event, says John Mulcahy, Link Research Ltd. general manager.
The system has been in use at virtually every big HD event since last
The system is currently
available in the U.S.
for rent from Aerial Video Systems and Broadcast Sports. Mulcahy says the HD
system builds on knowledge the company learned working in SD but required a
fresh look to ensure it could handle the rigorous demands of HD.
With HD we needed higher bit
rates and DVB-T would struggle at those higher rates, he says. It just wasn t
Link Research developed into
a new version of COFDM that had fewer carriers than DVB-T and a little more
bandwidth courtesy of a 9.4 MHz pedestal. We changed the error correction to
Low Density Parity Coding (LDPC) to make it the most powerful system around,
says Mulcahy. This added 1.5 to 2 dB to the link margin which made it more
The more powerful error
correction meant more bits could be used for video data. Between the wider
pedestal and the more powerful error correction we were able to get 60% more
data through the channel, says Mulcahy.
Using 16QAM LinkHD deliver HD
signals at 18.5 Mbps with only 45 milliseconds of delay. Using our own MPEG
encoding meant an ultra-low delay that was fully compliant with standards,
For those looking for more
bandwidth two channels can be used to deliver 38 Mbps with the same robustness.
But expect even more next April at NAB.
This is just our first
generation, says Mulcahy. In the next generation we ll bring the power down
even further and make it even more compact, he says.