In any system that uses quadrature amplitude modulation (QAM), there will be modulators and demodulators. These QAM modulators and demodulators are required to provide the capability to modulate both the in-phase and quadrature components of the modulating signal onto the carrier. QAM is used in a variety of communications systems such as Dial-up modems and WiFi.
Digital modulator for HD video distribution over coax - QAM, ATSC, DVB-T. Broadcast to unlimited TVs with FULL HD live HDMI video as Cable TV & IPTV channels
Features
Integrates fully independent encoders with a multiplexer and modulator
Modulates up to 4 adjacent QAM-256 carriers with up to 38 Mbps each
Supports full HD 1080p60 input & encoding from any HDMI digital video source
Each encoder independently configured: supports all standard HDTV resolutions
IPTV output on second network port in UDP IGMP Multicast or Unicast format
DVB-ASI output on mirrored BNC terminals for use in broadcasting systems
Fully network managed device with all settings configurable through web browser
Conversions : HDMI to RF, HDMI to IP, HDMI to ASI
Any 1-4 HDMI Input up to 720p/1080i/1080p60
Licensed HDMI inputs
1-4 CATV RF Output up to 4 Adjacent channels
QAM-256/64
Fully IP control and Network Management through browser
Front Panel LCD local control
IPTV Output Unicast or Multicast IGMP UDP, RTP/RTSP
ASI Output with multiplexer cherry picking
Low Latency available 300/500/800ms delay via different modes - IP will always be closer to 800ms due to the decoding (these values are end to end, not just the encoding speed)
AC3 Audio available (AC3 model)
MPEG2 Video or MPEG4 H.264 Encoding
Firmware for ATSC, DVB-T, DVB-S2 Available
2 slot design – Other Video Inputs cards available –Hot swappable - SDI Card, YpbPr Card.
This Device is a CMOD series compact Encoder Modulator with support for the Dolby AC/3 Audio Codec. This model line provides support for legacy USA tuners requiring the AC/3 audio codec for proper decoding.
Features
HDMI Input up to 1.5A @1080p60
HDCP licenced
Play any recorded TS file from USB Drive
1 HDTV Carrier RF Output full HD 1080p60
Record Live HD Video Input to USB TS File
Loop content from USB drive continuously
1 HDTV Carrier RF Output full HD 1080p60
Record Live HD Video Input to USB TS File
Loop content from USB drive continuously
AC3 Audio Encoding Avialable (model number specific)
Integrates fully independent encoders with a TS Generator and modulator
Available for most world RF channel formats: QAM, ATSC, DVB-C, DVB-T
Supports full HD 1080p60 input & encoding from any HDMI input source
Models supporting AC3 Dolby audio have official licenced encoding chipsets
USB storage feature for recording input and playing TS files from any source
Adjustable output power eliminates the need for RF amplifier, > +40 dBmV
Supports alternate encoding cards for application specific projects- Inquire
Support CC (Closed Caption) EIA608 (from CVBS input)
1-4 CATV RF Output up to 4 Adjacent channels
QAM-256/64, DVB-T & ATSC formats available
Fully IP Control and Network Management through browser
Front Panel LCD local control
IPTV Output Unicast or Multicast IGMP UDP, RTP / RTSP
ASI Output multiplexer with cherry picking
Low Latency available 300/500/800ms delay via different modes - IP will always be closer to 800ms due to the decoding (these values are end to end, not just the encoding speed)
Dolby AC3 or MPEG1/2 Audio Encoding
MPEG2 or MPEG4 H.264 Video Encoding
Firmware for ATSC, DVB-T, DVB-S2 Available
VCT (Virtual Channel Table) support for DVB-C and ATSC
This Unit has 12 HDMI inputs which are beeing converted to CABLE TV Channels for easy HD video distribusion over COAX. In addition it also has IPTV output for IP Network Multicast
HD (1080i/720p) to SD (576p/480p) downscale conversion
1MPTS and 24 SPTS IP (DATA1 and DATA2 port) output over UDP, RTP/RTSP
ASI output mirrors one of the RF carriers
PID remapping/ accurate PCR adjusting/PSI/SI editing and inserting
Control via web management NMS
16 Groups Multiplexing/Scrambling/ DVB-C QAM ANNEX A and B Modulating (based on RF)
8 Groups Multiplexing/ DVB-T/ATSC Modulating (based on RF)
6 Groups Multiplexing / ISDB-T Modulating (based on RF)
Up to 16 MPTS IP (Data2 Port Only) output over UDP, RTP/RTSP (# of MPTS is based on RF standard of device) (16MPTS for DVB-C; 8MPTS for DVB-T/ATSC; and 6MPTS for ISDB-T)
Supports multiple digital TV standard (ATSC, DVB-C (Cable QAM), ISDB-T, DVB-T )
Easy to use color LCD panel and 6 key buttons
Supports AC3 and AAC
Optimized for cascading multiple modulators on your coaxial network
Available in rackmount design to easily implement many units in a single chassis for simple expansion - Available in vertical slot chassis up to 12 units or single 1RU for up to 4 units
QAM modulators are electronic devices which create QAM channels on a cable TV or any other various type of distribution systems. Toner Cable Equipment also carries ASI modulators, which generate an 8VSB modulation, such as that used in off-air broadcast transmission. Quadrature Amplitude Modulation is the modulation standard used over cable TV systems. The modulators take an input signal, typically an ASI or NIP signal, to generate the QAM channels. They can be single-channel QAM modulators, multi-channel modulators (ex. Edge-QAM modulator).
Modulators can handle SD or HD content, otherwise known as “SD modulator” or “HD modulator.” Edge-QAM modulators typically take a package of multiple programs or multiple channel packages, and modulate them onto multiple QAMs. Edge-QAM modulators are typically available from an 8-QAM version, all the way up to a 264-QAM version.
QAM demodulators
The QAM demodulator is simply the reverse of the QAM modulator. The signals enter the system, next they are split and each side is applied to a mixer. One half has the in-phase local oscillator applied and the other half has the quadrature oscillator signal applied. A basic modulator assumes that the two quadrature signals remain exactly in quadrature. A further requirement is to derive a local oscillator signal for the demodulation that is exactly on the required frequency for the signal. Any frequency offset will be a change in the phase of the local oscillator signal with respect to the two double sideband suppressed carrier constituents of the overall signal.
Pros and cons of QAM
The major benefit of QAM modulation variants is efficient usage of bandwidth. This is due to the fact that QAM represent more number of bits per carrier. For example, 16QAM maps 4 bits per carrier, 64QAM maps 6 bits per carrier, 256QAM maps 8 bits per carrier and so on. On the other hand, QAM has some disadvanteges too. QAM modulation is more susceptible to the noise. Due to this QAM receiver is more complex in comparison to receivers of other modulation types. As QAM uses amplitude component of signal to represent binary data, linearity needs to be maintained and hence linear amplifier is needed. That means consuming more power.