Inmarsat-D/D+ Downlink

From Signal Identification Wiki
(Redirected from Inmarsat-D+ Downlink)
Jump to: navigation, search
Inmarsat-D/D+ Downlink - Inmarsat IsatM2M
Inmarsat-D/D+ Downlink
Inmarsat D.jpg
Frequencies 1525.0 MHzMegaHertz (MHz) 10^6 Hz1,525,000,000 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz).
1,525,000 kHzKiloHertz (kHz) 10^3 Hz
,1559.0 MHzMegaHertz (MHz) 10^6 Hz1,559,000,000 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz).
1,559,000 kHzKiloHertz (kHz) 10^3 Hz
1,525,000 kHzKiloHertz (kHz) 10^3 Hz
1,525 MHzMegaHertz (MHz) 10^6 Hz
1,559,000 kHzKiloHertz (kHz) 10^3 Hz
1,559 MHzMegaHertz (MHz) 10^6 Hz
Frequency Range 1,525 MHzMegaHertz (MHz) 10^6 Hz1,525,000,000 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz).
1,525,000 kHzKiloHertz (kHz) 10^3 Hz
- 1,559 MHzMegaHertz (MHz) 10^6 Hz1,559,000,000 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz).
1,559,000 kHzKiloHertz (kHz) 10^3 Hz
Mode USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables)
Modulation MFSKMultiple Frequency Shift-Keying
ACFAutoCorrelation Function
Bandwidth 640Hz0.64 kHzKiloHertz (kHz) 10^3 Hz
6.4e-4 MHzMegaHertz (MHz) 10^6 Hz
0.64 kHzKiloHertz (kHz) 10^3 Hz
6.4e-4 MHzMegaHertz (MHz) 10^6 Hz
0.64 kHzKiloHertz (kHz) 10^3 Hz
6.4e-4 MHzMegaHertz (MHz) 10^6 Hz
Location Worldwide
Short Description Inmarsat D+ (and it's predecessor, Inmarsat D) is Inmarsat's satellite paging system. The main use of this technology nowadays is in tracking trucks and buoys and SCADA applications.
I/Q Raw Recording Download file
Audio Sample
Inmarsat D+ (and it's predecessor, Inmarsat D) is Inmarsat's satellite paging system. The main use of this technology nowadays is in tracking trucks and buoys and SCADA applications. The original Inmarsat-D terminals were one-way (to mobile) pagers. The newer Inmarsat-D+ terminals are the equivalent of a two-way pager. This signal is the downlink from satellite to mobile station.


Characteristics[edit]

The downlink comprises of a 32 MFSKMultiple Frequency Shift-Keying signal at symbol rates of 4 sym/s or 8 sym/s for data rates of 20 bpsBits per second (bps) and 40 bpsBits per second (bps) respectively. Reed-Solomon (31,15) FECForward Error Correction is used on downlink.

The 4 sym/s signal has shift of 20 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz). for each tone. The bandwidth of the signal is ~640 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz)., but the channel allocated to the downlink is 2.5 kHzKiloHertz (kHz) 10^3 Hz wide to account for doppler shifting interference. There is a frequency shift of 20 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz). for each tone.

Samples[edit]

Inmarsat Downlink @ 4 sym/s:
(Sample contributed by RAPIDBIT)
(Sample contributed by UHF-SATCOM)

IQ Sample contributed by RAPIDBIT

Frequencies[edit]

  • Rx (Downlink): 1525.0 to 1559.0 MHzMegaHertz (MHz) 10^6 Hz
  • Tx (Uplink): 1626.5 to 1660.5 MHzMegaHertz (MHz) 10^6 Hz

Additional Links[edit]

Additional Images[edit]