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Explain the Intermodulation noise & saturation flux density? Explain the operation of FDMA system with relevant diagram.

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Question ajoutée par PAPPU MAJUMDER , Microsoft Business intelligence (MSBI) , Equifax
Date de publication: 2016/02/07

FIGURE 2 (optional)

Links involved in beyond line-of-sight (BLOS) communications via satellite

 

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As the regulatory conditions differ in each frequency band allocated to the fixed-satellite service, the characteristics define a typical system which can be assumed as representative for all cases, except other noted. Tables are numbered with a sequence number for quick references and corresponding comments in the second column of each table with reference to Recommendation ITU-R S., as appropriate.

The terms "Ku-band" and "Ka-band" address all eligible frequency bands allocated to the FSS, as defined the Tables below, respectively, but that are not subject to provisions of RR Appendix,A, andB as excluded by Resolution (WRC).

 

2         Typicalparameters for link budgets of Ku band FSS (/ GHz range) 2.1        GSO Satellite system parameters for link budgets Ku-band

Table1 defines a satellite constellation with a GSO satellite at a slant range at° elevation. Two cases define the conditions for hemispheric and spot beam, respectively.

Table1

Representative characteristics of GSO satellite systems

1         

 

GSO System

Units

Parameter for beam type1

Parameter for beam type2

2         

1.       

System

3         

1.1   

Information provider

 

Administration

Administration

4         

1.2   

Space station description

 

Satellite hemi

(HPBW »4°)

Satellite Spot

(HPBW »2°)

5         

1.3   

Carrier number

 

CNPC-1

CNPC-2

6         

2.       

Satellite Parameters

7         

2.1   

Orbital position(1)

°East

8         

2.2   

Type of transponder (transparent, regenerative)

 

Transparent(2)

Transparent(2)

Note1: The orbital position itself is less critical – in fact the elevation and the distance to the service area determines the actual link budget.The orbital position is referring to an E/S location in Berlin, Germany assuming an elevation of°

Note2: Worst case for link budgets, representative for existing systems

 

2.2        Space station parameters for link budgets (Ku-band)

Table2

Representative characteristics of space station parameters

9         

 

GSO System

Units

Parameter for beam type1 (hemi)

Parameter for beam type2 (spot)

     

3.       

Space Station

     

3.1   

Receive antenna gain towards transmitting earth station at EoC

dBi

.6

.3

     

3.2   

Satellite receive noise temperature

K

     

3.3   

G/T (at EoC)

dB/K

1

7.4

     

3.4   

SFD range (IBO determination) at ground level

dBW/m²

-.5 … -.5

-.9 … -.9

     

3.5   

Maximum EIRP (center of beam, hardware capability)

dBW

.5

.7

     

3.6   

EIRP variations (daily, life time)

dB

1.5

1.5

     

3.7   

Maximum possible EIRP per UA TC carrier (link #2) towards receiving earth station from link budgets

dBW

.5

.5

     

3.8   

Pointing error satellite beam(Note1)

dB

N/A

N/A

     

3.9   

Cross Polarization Discrimination

dB

each, uplink and downlink

each, uplink and downlink

     

3.           

ALC range if installed and operated

dB

0

0

     

3.           

Intermodulation impact, C/IM ratio at HPA

dB

     

3.           

Operational antenna gain range towards UA compared to maximum

dB

-6

(EoC –3 dB)

-6

(EoC –3 dB)

Note1: According to # a -3 dB gain penalty compared to EoC is already included.

 

 

 

 

2.3        Carrier parameters for link budgets (Ku-band)

Transmission characteristics of typical communication satellites operating in the FSS are provided in Table 3.

Table3

Representative characteristics of carrier parameters

 

 

GSO System

Units

Parameter set type1

Parameter set type2

Parameter set type3

     

4.       

Carrier Parameters

 

 

 

 

     

4.1   

Uplink type (typical, min, max)

 

Minimum w. r. t. terminal performance

Maximum w. r. t. terminal performance

 

     

4.2   

Downlink type (typical, min, max)

 

Minimum w. r. t. terminal performance

Maximum w. r. t. terminal performance

 

     

4.3   

Center frequency of uplink band

GHz

.0

.0

.0

     

4.4   

Uplink polarization

 

V

V

V

     

4.5   

Center frequency of downlink band

GHz

.

.

.

     

4.6   

Downlink polarization

 

H

H

H

     

4.7   

Access type (SCPC, TDMA)

 

SCPC

SCPC

SCPC

     

4.8   

Uplink access type for carriers using regenerative

Transponders

 

N/A

N/A

N/A

     

4.9   

Modulation uplink

 

BPSK

QPSK

BPSK

     

4.           

Modulation downlink (in case of reg. transp.)

 

N/A

N/A

N/A

     

4.           

Channel coding uplink

 

FEC-1/3

FEC-1/2

FEC-1/2

     

4.           

Channel coding downlink (in case of reg. transp.)

 

N/A

N/A

N/A

     

4.           

Information data rate uplink carrier

(Report ITU-R M.)

kbps

FW (TC):

RT (TM):

FW (TC):

RT (TM):

FW (TC):

RT (TM):

     

4.           

Information data rate downlink carrier (in case of regenerative transponder)

 

N/A

N/A

N/A

     

4.           

Data overhead uplink (e. g. TDMA overhead)

%

0

0

0

     

4.           

Data overhead downlink in case of reg. transp. (e. g. TDMA overhead)

%

N/A

N/A

N/A

     

4.           

Symbol rate uplink carrier

kSps

FW (TC):

RT (TM):

FW (TC):

RT (TM):

FW (TC):

RT (TM):

     

4.           

Symbol rate downlink carrier (reg. transp.)

kSps

N/A

N/A

N/A

     

4.           

Roll-off Uplink

%

     

4.           

Roll-off downlink (in case of regenerative transponder)

%

N/A

N/A

N/A

     

4.           

Occupied bandwidth uplink

kHz

FW (TC):

RT (TM):

FW (TC):

RT (TM):

FW (TC):

RT (TM):

     

4.           

Occupied bandwidth downlink (reg. transp.)

kHz

N/A

N/A

N/A

     

4.           

ACM range (if any)

dB

0

0

0

     

4.           

Required Eb/N0 (end-to-end), incl.1 dB margin *

dB

4

4.3

3

Note1: Number also covers existing UA solutions

 

2.4        UA Earth station parameters for link budgets in Ku-band(Ku-band)

Table4 provides the characteristics of Earth stations on-board aircraft in accordance with definition of RR no.1.. Three different types of AES on-board Unmanned Aircraft, reflecting the operational conditions of typical applications comprising medium-altitude long endurance (MALE) and high-altitude long endurance (HALE) Unmanned Aircrafts.

Table4

Representative characteristics of UAAES parameters

 

 

UA Earth Station on-board aircraft (AES)

Units

Parameter for UA  type1

Parameter for UA type2

Parameter for UA type3

     

5.       

RF front end

     

5.1   

Antenna size

cm

     

5.2   

Receive antenna gain

dBi

.5

.7

 

.6

     

5.3   

Receive noise temperature (elevation°)

K

     

5.4   

G/T at° elevation

dB/K

8.5

.7

 

.6

     

5.5   

Transmit antenna gain

dBi

.7

.8

 

.7

     

5.6   

Radome loss for each transmit and receive

dB

1

1

1

     

5.7   

Pointing error

dB

0.1

0.5

0.5

     

5.8   

Maximum EIRP (hardware capability)

dBW

.5

.4

     

5.9   

Operational EIRP for TM, maximum possible from hardware and regulatory point of view

dBW

.1

.5

.7

     

5.           

EIRP limited at first by

 

RecommendationITU-R S.

Available EIRP of UA (and ITU-R S.)

D/L EIRP-D for PFD limit

     

6.       

Receiver / Transmitter

     

6.1   

Output power at antenna input

W

     

6.2   

Intermodulation impact, C/IM ratio (Two carrier mode TM + sensor)

dB

     

6.3   

UPC range (if any)

dB

0

0

0

     

6.4   

UPC step size

dB

N/A

N/A

N/A

     

6.5   

Minimum power level for Rx sync.

dBm

N/A

N/A

N/A

               

Note1: Antenna efficiency is assumed as% (instead of% typical for reflector antennas).

Note2:  Values show worst case for reflector antennas. Planar antennas for high elevations (look angles perpendicular to the antenna plane), the complete effects of planar antennas with varying G/T and antenna pattern dependent on the look angle are not covered.

 

2.5        Typical UACS Earth station parameters in Kuband for link budgets

Table5 provides the characteristics of Earth stations remotely controlling Unmanned Aircraft via the communication satellite in accordance with definition of RR no.1.. Two typical Types of Earth stations for the beyond line of sight control, i.e. via communication satellites, are provided in Table5.

Table5

Representative characteristics of Ku-bandEarth Stationsused as Control Stations for UA (UACS)

 

 

UACS Earth Station

Units

Parameter for UACS  type1

Parameter for UA type2

     

7.       

 

     

7.1   

Antenna size

m

3.9

6.2

     

7.2   

Receive antenna gain

dBi

.7

.3

     

7.3   

Receive noise temperature

K

     

7.4   

G/T at° elevation

dB/K

.6

.8

     

7.5   

Transmit antenna gain

dBi

.7

.3

     

7.6   

Pointing error (incl. autotrack)

dB

0.2

0.2

     

7.7   

Maximum EIRP (hardware limit)

dBW

     

8.       

 

     

8.1   

Output power at antenna input (including OBO)

W

     

8.2   

Intermodulation impact, C/IM ratio (multiple TCs)

dB

     

8.3   

UPC range (if any)

dB

     

8.4   

UPC step size

dB

1

1

 

2.6        Transmission parameters for Ku band link budgets

Table6 provides the transmission parameters for typical Ka band SATCOM links via one set. The link budgets have been performed in a static way, considering the UA AES on ground and elaborating the maximum achievable rain margin on top of all other transmission losses. These rain margins are the basis for the2nd step of assessments, the link availability as a function of climatic zones, elevation, and UA AES flight height.

Table6

Representative characteristics of Ku-band transmission parameters

     

 

GSO System

Units

Parameter set1

     

9.       

 

     

9.1   

Location longitude (location: Berlin)

° East

.4

     

9.2   

Location latitude (location: Berlin)

° North

.5

     

9.3   

Slant range Uplink (° elevation)

km

2

     

9.4   

Slant range Downlink (°elevation)

km

2

     

9.5   

Permanent propagation losses uplink (atmospheric, scintillation);

Rec.s ITU-R P., P., P., P.

dB

2.4

0.4 dB for atmospheric losses),

2.0 dB for tropospheric scintillation for.%

     

9.6   

Permanent propagation losses downlink (atmospheric, scintillation);

Rec.s ITU-R P., P., P., P.

dB

1.8

0.3 dB for atmospheric losses),

1.5 dB for tropospheric scintillation for.%

     

9.7   

Climatic zone (ITU-R model)

 

[to be analyzed]

     

9.8   

Link availability uplink

%

     

9.9   

Link availability downlink

%

     

9.           

Rain losses UA uplink

dB

UACS uplink:

UA uplink: ≥5

as minimum value, link budget will give the maximum achievable one

     

9.           

Rain losses UA downlink

dB

UACS downlink (incl. atmosp. + scint.):8

UA downlink (incl. atmosp. + scint.): ≥4

as minimum value, link budget will give the maximum achievable one

     

9.           

Rain based G/T degradation

dB

UACS:3.4

UA:2.8

     

9.           

Polarization losses UA uplink

dB

0.5

     

9.           

Polarization losses UA downlink

dB

0.5

 

3         Typicalparameters for link budgets ofKa band FSS systems( / GHz)

The term "Ka-band" addresses all eligible frequency bands that are allocated to the FSS as defined in Table1 but that are not subject to provisions of RR Appendix,A, andB as excluded by Resolution (WRC).

3.1        GSO Satellite system parameters for link budgets studies (Ka-band)

Table7

Representative Ka-band satellite system parameters

1          

 

GSO System

Units

Parameter for beam type1

Parameter for beam type2

2          

1.       

System

3          

1.1   

Information provider

 

Administration

Administration

4          

1.2   

Space station description

 

Satellite single spot beam

(HPBW »1.4°)

Satellite multi spot beam (HPBW <0.8°)

5          

1.3   

Carrier number

 

CNPC-3

CNPC-4

6          

2.       

Satellite Parameters

7          

2.1   

Orbital position(1)

°East

8          

2.2   

Type of transponder (transparent, regenerative)

 

Transparent(2)

Transparent(2)

Note1: The orbital position itself is less important – in fact the elevation and distance to the service area is link budget defining, i. e. the relation between coverage latitude / longitude and satellite longitude (see chapter4.6); the orbital position in this example is adapted to the E/S location example of Berlin / Germany and the elevation of degrees

Note2:  For link budgets the worst case, but close to the existing system realizations; In this case the differentiation in Table1.3 between uplink and downlink is not needed, the figures are end-to-end ones

 

3.2        Space station parameter for link budgets (Ka-band)

Table8

Representative characteristics of Ka-band space stations

 

9          

 

GSO System

Units

Parameter for beam type1

Parameter for beam type2

      

3.       

Space Station

      

3.1   

Receive antenna gain towards transmitting earth station at EoC

dBi

 

      

3.2   

Satellite receive noise temperature

K

      

3.3   

G/T (EoC)

dB/K

9.0

      

3.4   

SFD range (IBO determination)

dBW/m²

- … -

- … -

      

3.5   

Maximum EIRP (center of beam)

dBW

      

3.6   

EIRP variations (daily, life)

dB

2

2.5

      

3.7   

Maximum possible EIRP per UA TC carrier towards receiving earth station from link budgets

dBW

.5

.5

      

3.8   

Pointing error satellite beam(Note1)

dB

N/A

N/A

      

3.9   

Cross Polarization Discrimination

dB

each, uplink and downlink

each, uplink and downlink

      

3.           

ALC range if installed and operated

dB

0

0

FDMA(Frequency division multiple techniques) TDMA (Time division multiple techniques)

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