CommSystem: Link Information

Link information provides the link budget for the CommSystem including interference parameters.

Type: Time-varying data. May supply data with duplicate times. Intended to be used only with elements from this same data provider.

Availability: Reports

NameDimensionTypeDescription
TimeDateFormatReal NumberTime.
Xmtr NameUnitlessTextName of the Transmitter used in the link.
Rcvr NameUnitlessTextName of the Receiver used in the link.
Link To IDUnitlessIntegerRefers to the ID of the transmitter in the link analysis.
Multibeam Antenna Beam-IDUnitlessTextRefers to the ID of the beam within the Multibeam Transmitter used in the link analysis.
Xmtr PowerPowerUnitReal Number The RF power output of the transmitter as measured at the input to the antenna. This is a user selectable value.
Xmtr GainRatioUnitReal NumberThe 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.
EIRPPowerUnitReal NumberThe 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 - PhiAngleUnitReal NumberThe transmitter azimuth (Phi) is the angle between the transmitter body +x axis and the x-y projection of the link vector.
Xmtr Elevation - ThetaAngleUnitReal NumberThe transmitter elevation (Theta) is the angle between the transmitter antenna bore-sight vector and the link vector.
Rcvr Azimuth - PhiAngleUnitReal NumberThe receiver azimuth (Phi) is the angle between the receiver body +x axis and the x-y projection of the link vector.
Rcvr Elevation - ThetaAngleUnitReal NumberThe receiver elevation (Theta) is the angle between the receiver antenna bore-sight vector and the link vector.
Multibeam Rcvr Antenna Beam-IDUnitlessTextMultibeam antenna beam ID refers to the ID of the beam within the multibeam receiver used in the link analysis.
Rcvd. FrequencyFrequencyUnitReal NumberThe 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 ShiftFrequencyUnitReal NumberThe 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. PowerPowerUnitReal NumberReceived 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 InputPowerUnitReal NumberCarrier 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 DensityPowerFluxDensityReal NumberThe power from the desired transmitter crossing a unit area normal to the direction of wave propagation.
Rcvr GainRatioUnitReal Number Receiver Gain is the antenna gain (in dBi) of the receiver which is dependent on the antenna type used.
TrainTemperatureReal NumberTrain is the antenna noise temperature component attributed to the rain model.
TatmosTemperatureReal NumberTatmos is the antenna noise temperature component attributed to the gaseous absorption model.
TsunTemperatureReal NumberTsun is the antenna noise temperature component attributed to the sun.
TearthTemperatureReal NumberTearth is the antenna noise temperature component attributed to the earth. This is applicable only to receivers not on the ground.
TcosmicTemperatureReal NumberTcosmic is the antenna noise temperature component attributed to the cosmic background. This is applicable only to receivers not on the ground.
TuserCustomATemperatureReal NumberTuserCustomA is the antenna noise temperature component attributed to user defined custom loss model A.
TuserCustomBTemperatureReal NumberTuserCustomB is the antenna noise temperature component attributed to user defined custom loss model B.
TuserCustomCTemperatureReal NumberTuserCustomC is the antenna noise temperature component attributed to user defined custom loss model C.
TotherTemperatureReal NumberTother is the antenna noise temperature component attributed to other antenna noise sources.
TantennaTemperatureReal NumberTantenna is the antenna noise temperature which is the sum of all the noise source components.
TequivTemperatureReal NumberThe 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/TGainTempRatioReal 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/NoSpectralDensityReal NumberThe 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)SpectralDensityReal NumberThe 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.
BandwidthBandwidthUnitReal NumberBandwidth is the Receiver Bandwidth.
Bandwidth OverlapRatioUnitReal NumberThe 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/NRatioUnitReal NumberThe 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)RatioUnitReal NumberThe 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/NoRatioUnitReal NumberThe 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)RatioUnitReal NumberThe 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.
BERUnitlessReal 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+IUnitlessReal NumberBit 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/IRatioUnitReal NumberIn 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/SRatioUnitReal NumberJ/S is the jammer to signal ratio.
DeltaT/TRatioUnitReal NumberThe ratio of interference power spectral density Io and receiver noise spectral density No.
Pwr Flux DensityPowerFluxDensityReal NumberThe 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. AngleAngleUnitReal NumberThe angle corresponding to the relative mismatch between the transmitted signal polarization and the receiver polarization.
Polarization EfficRatioUnitReal NumberThe 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-IDUnitlessTextUnique ID for beam of a multibeam antenna.
Total Jammer Power At Rcvr InputPowerUnitReal NumberThe total interference/jamming power entering the receiver due to all visible jammers.
Total RF PowerPowerUnitReal NumberThe total RF power entering the receiver due to the desired signal carrier and all the visible interferers/jammers.
Total Power At Rcvr InputPowerUnitReal NumberThe 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 PowerPowerUnitReal NumberThe receiver's total internal noise power. Which is computed from the receiver noise figure, antenna to receiver cable loss and the cable ambient temperature.
IoverNRatioUnitReal NumberThe ratio of the total interference power as seen by the receiver across its entire bandwidth over the total receiver noise.
RangeDistanceUnitReal Number The range (i.e., distance between the primary and secondary object) at the given time.
UserCustomA LossRatioUnitReal NumberLoss calculated by custom loss scripting plugin model A (written in VBscript, Perl or MATLAB).
UserCustomB LossRatioUnitReal NumberLoss calculated by custom loss scripting plugin model B (written in VBscript, Perl or MATLAB).
UserCustomC LossRatioUnitReal NumberLoss calculated by custom loss scripting plugin model C (written in VBscript, Perl or MATLAB).
Free Space LossRatioUnitReal NumberLoss due to propagation through free space.
Atmos LossRatioUnitReal NumberLoss calculated by the selected atmosphere model.
UrbanTerres LossRatioUnitReal NumberLoss calculated by the selected Urban and Terrestrial model.
Rain LossRatioUnitReal NumberLoss calculated by the selected rain model.
CloudsFog LossRatioUnitReal NumberLoss calculated by the Clouds and Fog model.
TropoScintill LossRatioUnitReal NumberLoss calculated by the troposphere Scintillation model.
Prop LossRatioUnitReal NumberThe total propagation loss computed across all enabled propagation models.
TcloudsFogTemperatureReal NumberThe noise temperature from the Cloud and Fog model.
TtropoScintillTemperatureReal NumberThe noise temperature from the Troposhperic Scintillation model.
TexternalTemperatureReal NumberThe noise temperature specified by the external noise temperature file.
TUrbanTerresTemperatureReal NumberThe noise temperature corresponding to urban propagation loss.
Spectral Flux DensityPowerSpectralFluxDensityReal NumberThis 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).