Link information provides the link
budget for the CommSystem including interference parameters.
| Name |
Dimension |
Type |
Description |
| Time |
DateFormat |
Real Number |
Time. |
| Xmtr Name |
Unitless |
Text |
Name of the Transmitter used in the link. |
| Rcvr Name |
Unitless |
Text |
Name of the Receiver used in the link. |
| Link To ID |
Unitless |
Integer |
Refers to the ID of the transmitter in the link
analysis. |
| Multibeam Antenna Beam-ID |
Unitless |
Text |
Refers to the ID of the beam within the Multibeam
Transmitter used in the link analysis. |
| Xmtr Power |
PowerUnit |
Real Number |
The RF power output of the transmitter as measured
at the input to the antenna. This is a user selectable value. |
| Xmtr Gain |
RatioUnit |
Real Number |
The antenna gain of the transmitter which is
dependent on the antenna type selected. For transmitter models that
do not have an antenna model, this is a user defined value. For the
simple source transmitter, 0 dB is reported since the simple source
transmitter is modeled as an isotropic radiator. |
| EIRP |
PowerUnit |
Real Number |
The effective isotropic radiated power in the link
direction. This value is the product of the transmitter power and
the transmitter gain in the link direction with the inclusion of
user defined post transmit gains and losses. |
| Xmtr Azimuth -
Phi |
AngleUnit |
Real Number |
The transmitter azimuth (Phi) is the angle between
the transmitter body +x axis and the x-y projection of the link
vector. |
| Xmtr
Elevation - Theta |
AngleUnit |
Real Number |
The transmitter elevation (Theta) is the angle
between the transmitter antenna bore-sight vector and the link
vector. |
| Rcvr Azimuth -
Phi |
AngleUnit |
Real Number |
The receiver azimuth (Phi) is the angle between the
receiver body +x axis and the x-y projection of the link
vector. |
| Rcvr
Elevation - Theta |
AngleUnit |
Real Number |
The receiver elevation (Theta) is the angle between
the receiver antenna bore-sight vector and the link vector. |
| Multibeam Rcvr Antenna
Beam-ID |
Unitless |
Text |
Multibeam antenna beam ID refers to the ID of the
beam within the multibeam receiver used in the link analysis. |
| Rcvd. Frequency |
FrequencyUnit |
Real Number |
The received frequency is the frequency that the
receiver is tuned to in order to communicate with the transmitter.
This frequency may be auto-tracked or entered by the user in the
receiver properties. |
| Freq. Doppler
Shift |
FrequencyUnit |
Real Number |
The frequency Doppler shift is the offset in
frequency between the transmitted frequency and the received
frequency. This value is zero for auto tracked receivers. |
| Rcvd. Iso. Power |
PowerUnit |
Real Number |
Received isotropic power is the power at the
receiver before the pre-receive gains/losses and the receiver
antenna gain added (in dBW). It is equal to the EIRP with all the
channel losses as well as the bandwidth overlap applied. |
| Carrier Power at Rcvr Input |
PowerUnit |
Real Number |
Carrier Power at Rcvr Input is the power at the
receiver after the receiver antenna gain added (in dBW). It is
equal to the EIRP with all the channel losses as well as the
bandwidth overlap and receiver gain applied. |
| Flux Density |
PowerFluxDensity |
Real Number |
The power from the desired transmitter crossing a
unit area normal to the direction of wave propagation. |
| Rcvr Gain |
RatioUnit |
Real Number |
Receiver Gain is the antenna gain (in dBi) of the
receiver which is dependent on the antenna type used. |
| Train |
Temperature |
Real Number |
Train is the antenna noise temperature component
attributed to the rain model. |
| Tatmos |
Temperature |
Real Number |
Tatmos is the antenna noise temperature component
attributed to the gaseous absorption model. |
| Tsun |
Temperature |
Real Number |
Tsun is the antenna noise temperature component
attributed to the sun. |
| Tearth |
Temperature |
Real Number |
Tearth is the antenna noise temperature component
attributed to the earth. This is applicable only to receivers not
on the ground. |
| Tcosmic |
Temperature |
Real Number |
Tcosmic is the antenna noise temperature component
attributed to the cosmic background. This is applicable only to
receivers not on the ground. |
| TuserCustomA |
Temperature |
Real Number |
TuserCustomA is the antenna noise temperature
component attributed to user defined custom loss model A. |
| TuserCustomB |
Temperature |
Real Number |
TuserCustomB is the antenna noise temperature
component attributed to user defined custom loss model B. |
| TuserCustomC |
Temperature |
Real Number |
TuserCustomC is the antenna noise temperature
component attributed to user defined custom loss model C. |
| Tother |
Temperature |
Real Number |
Tother is the antenna noise temperature component
attributed to other antenna noise sources. |
| Tantenna |
Temperature |
Real Number |
Tantenna is the antenna noise temperature which is
the sum of all the noise source components. |
| Tequiv |
Temperature |
Real Number |
The equivalent system temperature is specified by
the user as a constant value or computed at each time step from the
receiver system temperature parameters defined by the user. |
| g/T |
GainTempRatio |
Real Number |
G/T = (Receiver Gain)/(System Temperature at the
Receiver). The ratio of the receive antenna gain G to the total
system temperature T is the "figure of merit" for the receiver (in
dB/K). The figure of merit is independent of the point where it is
calculated. However, the gain and system temperature must be
specified at the same point. |
| C/No |
SpectralDensity |
Real Number |
The carrier to noise density ratio (C/No) where C
is the carrier power and No = kT (Boltzmann's constant x system
temperature) is the noise density. It is equivalent to C/N with a
normalized Bandwidth (B=1). |
| C/(No+Io) |
SpectralDensity |
Real Number |
The carrier to (noise + interference) ratio
(C/(No+Io)) where C is the carrier power, No = kT (Boltzmann's
constant * system temperature) and Io = interference power spectral
density. |
| Bandwidth |
BandwidthUnit |
Real Number |
Bandwidth is the Receiver Bandwidth. |
| Bandwidth
Overlap |
RatioUnit |
Real Number |
The bandwidth overlap factor is the fraction
(between 0 and 1) of transmitted power which is contained within
the receiver's bandwidth. The amount of power received by the
receiver is equal to the transmitted EIRP multiplied by the
bandwidth overlap factor and taking into account any propagation
losses. |
| C/N |
RatioUnit |
Real Number |
The carrier to noise ratio (C/N) where C is the
carrier power and N = kTB (Boltzmann's constant x system
temperature x bandwidth) is the noise power. |
| C/(N+I) |
RatioUnit |
Real Number |
The carrier to (noise + interference) ratio
(C/(N+I)) where C is the carrier power, N = kTB (Boltzmann's
constant * system temperature * bandwidth) and I = interference
power. |
| Eb/No |
RatioUnit |
Real Number |
The energy per bit to noise ratio (Eb/No) where Eb
is the energy per bit and No = kT (Boltzmann's constant * system
temperature). |
| Eb/(No+Io) |
RatioUnit |
Real Number |
The energy per bit to (noise + interference) ratio
(Eb/(No+Io)) where Eb is the energy per bit, No = kT (Boltzmann's
constant * system temperature) and Io = interference power spectral
density. |
| BER |
Unitless |
Real Number |
Bit Error Rate (BER) is the probability that a bit
is in error (i.e. a zero is transmitted but a one is received). The
BER is the number of bits in error divided by the total number of
bits sent. STK uses table lookup from a .mod file to extract a BER
given an Eb/No. STK interpolates the table as necessary to
determine the appropriate bit error rate for a particular bit
energy level. If the bit energy is smaller than the first value in
the table, the bit error rate for the first value is used. If the
bit energy is larger than the last value in the table, a default
bit error rate of 1.0e-30 is used to indicate no errors. |
| BER+I |
Unitless |
Real Number |
Bit error rate in the presence of interference
(BER+I) is the probability that a bit is in error (i.e. a zero is
transmitted but a one is received) in the interference environment.
The BER+I is the number of bits in error divided by the total
number of bits sent. STK uses table lookup from a .mod file to
extract a BER+I given an Eb/(No+Io). STK interpolates the table as
necessary to determine the appropriate bit error rate for a
particular bit energy level. If the bit energy is smaller than the
first value in the table, the bit error rate for the first value is
used. If the bit energy is larger than the last value in the table,
a default bit error rate of 1.0e-30 is used to indicate no
errors. |
| C/I |
RatioUnit |
Real Number |
In the Interference Information data provider, C/I
is the carrier power from the desired signal over the individual
interferer power. Note that the Link Information data provider
defines C/I as the carrier power from the desired signal over the
sum of all interferer powers. If only one interferer is part of the
CommSystem, the two data providers will report the same value for
C/I. |
| J/S |
RatioUnit |
Real Number |
J/S is the jammer to signal ratio. |
| DeltaT/T |
RatioUnit |
Real Number |
The ratio of interference power spectral density Io
and receiver noise spectral density No. |
| Pwr Flux Density |
PowerFluxDensity |
Real Number |
The interference power from an individual
interference source, crossing a unit area normal to the direction
of wave propagation and computed over a reference bandwidth of
either 1 MHz, 40 kHz, 4 kHz, or 1 Hz. See "Power Flux Density
Technical Notes". |
| Pol. Rel. Angle |
AngleUnit |
Real Number |
The angle corresponding to the relative mismatch
between the transmitted signal polarization and the receiver
polarization. |
| Polarization
Effic |
RatioUnit |
Real Number |
The polarization match between the transmitted
signal polarization and the receiving antenna (or in case of Simple
and Medium models implied antenna) polarization. It is computed on
a scale of 0 - - 1. The value of 1.0 represents the perfect match
between the transmitter and the receiver polarizations. On the
opposite end of the scale, the value of 0.0 represents a perfect
mismatch. STK also provides an option to model Cross Polarization
Leakage value. The polarization mismatch value can not drop below
the user specified Cross Pol Leakage value. |
| Multibeam Xmtr Antenna
Beam-ID |
Unitless |
Text |
Unique ID for beam of a multibeam antenna. |
| Total Jammer Power At Rcvr
Input |
PowerUnit |
Real Number |
The total interference/jamming power entering the
receiver due to all visible jammers. |
| Total RF Power |
PowerUnit |
Real Number |
The total RF power entering the receiver due to the
desired signal carrier and all the visible
interferers/jammers. |
| Total Power At Rcvr Input |
PowerUnit |
Real Number |
The total power received at the input of the
receiver front end amplifier, which includes antenna gain,
polarization mismatch, cable losses, etc. The total power is the
sum of the desired signal power and all received interference
signal power, in the direction of the interferer and within the
receiver's bandwidth. |
| Rcvr Noise Power |
PowerUnit |
Real Number |
The receiver's total internal noise power. Which is
computed from the receiver noise figure, antenna to receiver cable
loss and the cable ambient temperature. |
| IoverN |
RatioUnit |
Real Number |
The ratio of the total interference power as seen
by the receiver across its entire bandwidth over the total receiver
noise. |
| Range |
DistanceUnit |
Real Number |
The range (i.e., distance between the primary and
secondary object) at the given time. |
| UserCustomA Loss |
RatioUnit |
Real Number |
Loss calculated by custom loss scripting plugin
model A (written in VBscript, Perl or MATLAB). |
| UserCustomB Loss |
RatioUnit |
Real Number |
Loss calculated by custom loss scripting plugin
model B (written in VBscript, Perl or MATLAB). |
| UserCustomC Loss |
RatioUnit |
Real Number |
Loss calculated by custom loss scripting plugin
model C (written in VBscript, Perl or MATLAB). |
| Free Space Loss |
RatioUnit |
Real Number |
Loss due to propagation through free space. |
| Atmos Loss |
RatioUnit |
Real Number |
Loss calculated by the selected atmosphere
model. |
| UrbanTerres Loss |
RatioUnit |
Real Number |
Loss calculated by the selected Urban and
Terrestrial model. |
| Rain Loss |
RatioUnit |
Real Number |
Loss calculated by the selected rain model. |
| CloudsFog Loss |
RatioUnit |
Real Number |
Loss calculated by the Clouds and Fog model. |
| TropoScintill
Loss |
RatioUnit |
Real Number |
Loss calculated by the troposphere Scintillation
model. |
| Prop Loss |
RatioUnit |
Real Number |
The total propagation loss computed across all
enabled propagation models. |
| TcloudsFog |
Temperature |
Real Number |
The noise temperature from the Cloud and Fog
model. |
| TtropoScintill |
Temperature |
Real Number |
The noise temperature from the Troposhperic
Scintillation model. |
| Texternal |
Temperature |
Real Number |
The noise temperature specified by the external
noise temperature file. |
| TUrbanTerres |
Temperature |
Real Number |
The noise temperature corresponding to urban
propagation loss. |
| Spectral
Flux Density |
PowerSpectralFluxDensity |
Real Number |
This is the power per unit area per unit bandwidth.
The power is computed across the receiver's bandwidth as seen by
the receiver's RF front end. The bandwidth is the receiver's total
bandwidth. The dimension is Power / (Area * Bandwidth), and is
typically represented in dBW/(m^2*Hz). |