Proposal of structure:

Introduction - tell what is the aim of the project

State of art - talk about how L-band reception systems work currently

Project - Present our results, discuss them point by point

-Linearity - what is, show results, compare to the technical specification provided.

-Intermodulation - what is, show results, explain and compare to coax (theoretically)

-Phase/noise - what is, show results, explain and compare to coax (theoretically)

-Application

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1. Introduction¶

Earth stations are based on an indoor/outdoor unit architecture. The outdoor unit comprises antennas and the RF frontend (amplifier and up/down converter). The indoor unit includes the receiver, modem and network/application appliances. On typical consumer systems, the outdoor and indoor units are connected by means of a 75-ohm coaxial cable. The cable conveys the intermediate frequency (typically L band) signal between the indoor/outdoor units.

This approach, while being cost effective, is not optimal from a signal quality standpoint and might severely impair the end-to-end link budget. For example, typical attenuation values for a coaxial cable at a frequency of 1 GHz are in the order of 15 dB/100 m.

The objective of this project is to test and evaluate a system that makes possible to convert the L-band RF signal from/to optical and use an optical fibre (up to 10 km) as primary interconnection media. The signal is converted from optical back to RF in the indoor unit. As such, it is directed to DTH (Direct-To-Home) TV systems.

2. State of the art¶

3. Measures¶

3.1 Linearity¶

3.2 Intermodulation¶

3.3 Phase/Noise¶

4. Results¶

5. Conclusions¶

6. Application¶

This section explains how the Outdoor system has been installed and the results obtained measuring a real TV signal from a Satellite.

6.1 Preparation¶

The optical transmitter has been put in an hermetic box.

Its interface consists of :

• The power supply plug to be connected to the mains ;
• The optical fiber harness (2 fibers) : only the red fiber is actually connected to optical transmitter ; the black fiber is not used, it will enable to have a b ;
• The type F coaxial cable to connect the Antenna Low Noise Block, LNB, to optical transmitter.

Optical transmitter is set to :

• To supply 18 V to LNB, which selects Horizontale polarization ;
• To provide 0 kHz tone to LNB, which set its Local Oscillator to 9.75 GHz to transpose lower Ku Band from 10.7 to 11.7 GHz into IF Band.
• This hermetic box has been mounted on Antenna mast. This Antenna is pointing to Astra 1KR/1L/1M/1N colocalized satellites on 19.2° East.

6.2 Trials¶

6.2.1 IF Spectrum with Optical Link¶

RF output from Optical receiver has been analyzed with Rohde & Schwartz FSV spectrum analyzer :

IF Band, 1 Channel (with Optical Link)

It is possible to distinguish several channels within the Inter Frequency, IF, band. There is a zoom on left side. The 3 dB channel bandwdith is 22 MHz.
The power is about -32 dBm for the channel centered around 1141 MHz.

TV channel at 1141 MHz

6.2.2 Link Quality with Optical link¶

First, optical link performance enables to have a good TV quality (for example, Eins Plus on 10744H). More deeply, physical link quality has been assessed with the information provided by IPRICOT SCB router.
This data has been compared with data from website like [[www.lingsat.com]] :

Category	Make	Model	Remarks
Software defined radio	National Instruments	NI USRP 2920	Freq. coverage: 50-2200 MHz, BW: 20-40 MHz, Ethernet connectivity
Software defined radio	National Instruments	NI USRP 2920
Software defined radio	National Instruments	NI USRP 2920
Software defined radio	National Instruments	NI USRP 2950R	Freq. coverage: 50-2200 MHz, BW: 20-40 MHz, Ethernet and PXIe connectivity, GPS DO
Software defined radio	National Instruments	NI USRP 2950R	Freq. coverage: 50-2200 MHz, BW: 20-40 MHz, Ethernet and PXIe connectivity, GPS DO
Software defined radio	National Instruments	NI PXIe 5644R	Freq. coverage: 65-6000 MHz, BW: 80 MHz, PXIe connectivity, programmable FPGA, in a PXIe 1078 chassis
Software defined radio	National Instruments	NI PXIe 5644R	In the same chassis as the prior one
Satellite modem	Newtec	Elevation 470	DVB-S/S2 modem with ACM option, L-band IF
Satellite modem	Newtec	Elevation 470	DVB-S/S2 modem with ACM option, L-band IF
Satellite modem	Newtec	MDM 6000	DVB-S/S2/S2x modem with ACM option, L-band IF
Satellite modem	Newtec	MDM 6000	DVB-S/S2/S2x modem with ACM & BBF on Ethernet L-band IF
Satellite modem	ViaSat	RM 4100	TooWay KA SAT modem
Satellite receiver	IPricot	IPR-SC	DVB-S/IP receiver
Satellite antenna	AVL	AVL 9600K	Ku band drive-away antenna with LNB, BUC and controller
Satellite antenna	IGP	VPS-2	Ku band 1.2 m drive-away antenna with LNB and controller
Satellite antenna	IGP	?	Ku band 0.9 m fly-away antenna with LNB and BUC
Satellite antenna	Andrew	?	Direct-to-home TV 1.2 m antenna with universal LNB
Satellite antenna	Satcomm	KA-75D	Ka band fly away antenna with Viasat Tria
Satellite antenna	?	?	Ka band fixed antenna with Viasat Tria
Measurement instrument	Rohde & Schwarz	FSL-3	Spectrum analyzer 3 GHz
Measurement instrument	Rohde & Schwarz	FSV-3	Signal analyzer 3 GHz including K70 option (digital demod)
Measurement instrument	Agilent	34405	Tabletop multimeter
Measurement instrument	Agilent	DSO5052A	Digital storage oscilloscope 500 MHz / 4 Gsample/s
Measurement instrument	Agilent	E3646A	Power supply
Measurement instrument	NI	myRio 1900	All purpose D/A A/D instrument programmable with LabVIEW
Measurement instrument	NI	myRio 1900	All purpose D/A A/D instrument programmable with LabVIEW
Networking	CISCO	2811 serie	Router with 4+2 port ethernet/100 switch
Networking	CISCO	2811 serie	Router with 4+2 port ethernet/100 switch
Networking	CISCO	Catalyst 500	Managed 24 port ethernet/100 switch
Networking	DELL	PowerConnect 3324	Managed 24 port ethernet/100 switch
Networking	NORTEL	BayStack 470-48T	Managed 48 port ethernet/100 switch
Networking	Netgear	FS726T	Managed 24 port Ethernet/100 + 2 port Ethernet/1000 switch, fact default: 192.168.0.239 password is password
Networking	Leadtek	BVP 8770	Videoconference terminal
Networking	Leadtek	BVP 8770	Videoconference terminal
Networking	Mikrotik	SXT Lite5	Wifi 5 GHz transceiver with 16 dBi narrow aperture antenna and full stack support
Networking	Mikrotik	SXT Lite5	Wifi 5 GHz transceiver with 16 dBi narrow aperture antenna and full stack support
Networking	Mikrotik	SXT SA5	Wifi 5 GHz transceiver with 13 dBi wide aperture antenna and full stack support
RF	Lynx Technik	OTX 1900	L-Band to Optical converter
RF	Lynx Technik	ORX 1900	Optical to L-band converter
Radio communications	AOR	AR5000A	Analog radio receiver 0-1300 MHz (AM, FM, SSB)
Embedded computing	Raspberry foundation	Raspberry PI model B+
Embedded computing	Texas Instrument	TMS320VC5505 eZdsp USB stick	A DSP on a USB stick with audio I/O and expansion connector
Embedded computing	PC ENGINES GmbH	19" rack with 2 x APU1D4 PC engine	2 x embedded PC with 3 NIC for each PC
Misc	None	None	"Maxibox" field terminal providing LAN, WLAN, fixed phone and wireless phones in a ruggedised case