Difference between revisions of "Digital Video Transmission"

From MyLabWiki
Jump to: navigation, search
(New page: == Target Bitrates == === Using H.264 === * 1920 x 1080i (2-8 Mbps) * 1280 x 720p (1-4 Mbps) * ''704 x 480p (412 kbps to 2 Mbps)'' * 640 x 360 (256 kbps to 1 Mbps) Source: http://www.l...)
 
(GMSK)
Line 28: Line 28:
 
=== GMSK ===
 
=== GMSK ===
  
 +
Gaussian minimum shift keying or GMSK is a continuous-phase frequency-shift keying modulation scheme. It is similar to standard minimum-shift keying (MSK); however the digital data stream is first shaped with a Gaussian filter before being applied to a frequency modulator. This has the advantage of reducing sideband power, which in turn reduces out-of-band interference between signal carriers in adjacent frequency channels. However, the Gaussian filter increases the modulation memory in the system and causes intersymbol interference, making it more difficult to discriminate between different transmitted data values and requiring more complex channel equalization algorithms such as an adaptive equalizer at the receiver.
 +
 +
GMSK has high spectral efficiency, but it needs a higher power level than QPSK, for instance, in order to transmit the same amount of data reliably.
 +
 +
GMSK is used in GSM as well as in Space-to-Earth links for high-rate mission data.
 +
 +
[http://en.wikipedia.org/wiki/GMSK#Gaussian_minimum-shift_keying Wikipedia]
  
 
== Other Projects ==
 
== Other Projects ==

Revision as of 14:27, 30 September 2009

Contents

Target Bitrates

Using H.264

  • 1920 x 1080i (2-8 Mbps)
  • 1280 x 720p (1-4 Mbps)
  • 704 x 480p (412 kbps to 2 Mbps)
  • 640 x 360 (256 kbps to 1 Mbps)

Source: http://www.linuxfordevices.com/c/a/News/Panasonic-KXVC500/


Using OGG Theora

TBD


Using Dirac

TBD


Modulation

PSK

GMSK

Gaussian minimum shift keying or GMSK is a continuous-phase frequency-shift keying modulation scheme. It is similar to standard minimum-shift keying (MSK); however the digital data stream is first shaped with a Gaussian filter before being applied to a frequency modulator. This has the advantage of reducing sideband power, which in turn reduces out-of-band interference between signal carriers in adjacent frequency channels. However, the Gaussian filter increases the modulation memory in the system and causes intersymbol interference, making it more difficult to discriminate between different transmitted data values and requiring more complex channel equalization algorithms such as an adaptive equalizer at the receiver.

GMSK has high spectral efficiency, but it needs a higher power level than QPSK, for instance, in order to transmit the same amount of data reliably.

GMSK is used in GSM as well as in Space-to-Earth links for high-rate mission data.

Wikipedia

Other Projects

  • BATC Magazine TBD article