TELEMETRIX 400 CHANNEL SIMULATOR (T400CS)
OVERVIEW
 A member of the RT Logic Telemetrix® product line, the Telemetrix 400 Channel Simulator (T400CS) addresses a broad range of IF and RF hardware-in-the-loop test, operational, and training applications.

The T400CS creates RF and IF signals that precisely match those that occur when transmitters and receivers are in motion with respect to one another. By accurately duplicating the motion and RF channel physics effects on an RF link, the T400CS allows bench testing of what once required actual motion and distance between a transmitter and receiver. The T400CS enables comprehensive test and training activities without actual flights of the satellites, missiles, UAVs, targets, and aircraft carrying the transmitters or receivers under test.
T400CS channel effects include physics-compliant, phase-continuous, real-time carrier and signal Doppler shift, range delay, range attenuation, fading, and noise. In addition, multiple test and/or interference signals can be generated with the optional multi-channel signal source. A comprehensive selection of upconverters and downconverters are also available, allowing signals to be generated or received in frequency bands of interest.

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The T400CS client/server software architecture facilitates a wide range of local and remote control options. Local control is provided by an easy-to-use RT Logic Graphical User Interface (GUI). Users can also create their own channel simulation profiles from a comma separated listing of RF effects values. Programmatic control capabilities include a well-documented control protocol and an optional RT Logic plugin to the Analytical Graphics, Inc. (AGI) STK software. This provides a seamless real-time connection between the motion and RF modeling included in STK, and T400CS real-world creation of the physics compliant channel effects.
KEY
APPLICATIONS
 The T400CS is a general purpose RF and IF test and measurement instrument for communications system- and component-level testing and verification, both in the laboratory and in the field. Key applications include:

  • Flight system and ground system testing for satellite, UAV, missile, and target applications
  • Telemetry tracking system verification for test ranges
  • Reference signal and interference signal generation on-air or in the laboratory
  • Compliance testing
  • Performance testing
  • Diversity combining testing
  • Training and education
  • Realistic loop-back testing
CHANNEL SIMULATOR
 The RT Logic T400CS generates physics-compliant, phase-continuous, real-time carrier and signal Doppler shift, range delay, range attenuation, and Additive White Gaussian Noise (AWGN). These effects can be applied singly or in combination. Together, they precisely duplicate propagation effects encountered in LEO, MEO, HEO, and GEO satellite applications, as well as aircraft, UAV, missile, target, and range test scenarios.

The T400CS was designed to be expandable, allowing the system to cover a wide range of channel counts and frequencies. One channel simulator card is typically configured in a T400CS system to emulate a single communication path, for example, an uplink or a downlink. A single channel simulator card can also be used to simulate both uplink and downlink through bent-pipe transponders. When emulating a bidirectional or full duplex communication link, the T400CS system is typically configured with two channel simulator cards. Signal recorders/players, signal generators, and spectrum analyzers can also be included in the T400CS system, further expanding its testing capabilities. The T400CS can be inserted into a system under test in multiple ways, including direct cabling or utilizing amplifiers, signal conditioners, and antennas connected over the air.

Local control of the T400CS is accomplished through the use of the included GUI or simulation (SIM) files. Static changes to the channel simulator can be accessed through the GUI. SIM files are utilized for local control of real-time recreation of transmitters and receivers in motion. SIM files are created in standard Comma Separated Value (CSV) format, and can be based on range and time information, or can be built with Doppler, delay, attenuation, and noise values directly. SIM files can also be created from STK reports. SIM files allow developers to build nominal, worst-case, and mission specific scenarios, providing precise, repeatable, phase continuous local control of the T400CS.

Programmatic control of the T400CS is facilitated over an Ethernet connection utilizing a messaging protocol or optional RT Logic plugin to AGI’s STK software. When using STK and RT Logic’s plugin as the T400CS front-end control software, the channel simulator produces IF/RF signals with exacting signal behavior for any scenario. RT Logic’s STK plugin provides real-time, phase continuous control of the T400CS when playing back STK scenarios. STK provides intuitive, quick, and visual development of communication link scenarios, without requiring user expertise in channel models, propagation effects, link budgets, or orbital/flight science. Users with expertise in these areas can utilize their own simulation software or test executive, programmatically linking with the T400CS through the messaging protocol.
SIGNAL GENERATOR
 T400CS Signal Generator cards are capable of producing up to eight (8) signals with independently adjustable frequency offset, modulation type, data rate, PRN code (and trigger delay), amplitude, and filtering. These signals can be used as nominal test signals, or can be configured to represent worst-case signal conditions for comprehensive receiver system testing, diversity combiner testing, jammer rejection, etc. These signals can also be configured as interfering signals to test avoidance/mitigation capabilities.
SPECTRUM,
SIGNAL, AND
INTERFERENCE ANALYZER
 The T400CS’s Spectrum, Signal, and Interference Analyzer provides complete signal analysis and automated spectrum monitoring capability. Advanced features include display of C/No, Eb/No, BER, and C/I metrics as well as determination of carrier standard and inner coding schemes.

Sophisticated interference analysis processing allows identification and study of jammer, covert or accidental interference sources, and their impacts on signals of interest. Carrier-under-carrier analysis supports the identification and study of signals that may appear intentionally or unintentionally beneath the main signal.
FREQUENCY CONVERTERS
 RF up/downconverters are available for a wide range of input and output frequencies. This allows the T400CS to generate RF signals for realistic receiver testing.

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Similarly, the instrument can receive RF signals for realistic transmitter testing.

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Amplifiers and antennas can be selected for specific test scenarios, which may span distances of a few feet, hundreds of miles (e.g., range testing, on-air LEO satellite testing), or tens of thousands of miles (e.g., on-air GEO satellite testing).
HARDWARE ARCHITECTURE
 Standard T400CS architecture, as shown below, is implemented with a series of compact PCI (cPCI) modules controlled by a cPCI CPU running Microsoft® Windows XP Professional®.

The flexible architecture of the T400CS allows for multiple channel simulator cards, signal generator cards, spectrum analyzers, frequency converters, etc.

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SPECS
General
  • Intermediate Frequency (IF), 70/160/266 MHz
  • RF Input Frequencies (With Optional Downconverters)
UHF-Band, 225 To 400 MHz
L-Band, 950 To 1750 MHz
S-Band, 1650 To 3000 MHz
C-Band, 3.4 To 4.2 GHz
X-Band, 7.25 To 7.75 GHz
Ku-Band, 10.7 To 12.75 GHz

  • RF Output Frequencies (With Optional Upconverters)
UHF-Band, 225 To 400 MHz
L-Band, 950 To 1750 MHz
S-Band, 1650 To 3000 MHz
C-Band, 5.85 To 6.425 GHz
X-Band, 7.9 To 8.4 GHz
Ku-Band, 13.75 To 14.5 GHz

  • Compatible With Most Non-RT Logic 70/160/266 MHz IF Converters

Channel Simulation
  • Instantaneous Bandwidth, 40 or 85 MHz
  • Signal Doppler Shift, 0 KHz ±500 KHz, Phase-Continuous, 1 Hz Resolution
  • Carrier Doppler Shift, 0 KHz ±20/42.5 MHz, Phase-Continuous, 1 Hz Resolution
  • Range Delay, 3 µs To 1.25(85 MHz)/2.5 s (40 MHz), Phase-Continuous, 1 ns Resolution
  • Fading/Range Attenuation, Up To 60 dB, Phase-Continuous, 0.5 dB Resolution
  • AWGN, -168 dBm/Hz To -102 dBm/Hz
  • Receiver Noise, -168 dBm/Hz To -102 dBm/Hz
  • Amplitude Response, ±0.5 dB
  • Instantaneous Dynamic Range, 60 dB
  • Internal And External Trigger

Signal Generation
  • Channels, 8 Per Card
  • Standard Modulation Types, BPSK, QPSK, OQPSK, SOQPSK-TG and SOQPSK-MIL 8PSK, MSK, FSK, AM, FM, CW
  • Standard Filter Types, Rectangular, Raised Cosine (Cutoff 0.5, Roll Off 0.3), Root-Raised Cosine (Cutoff 0.5, Roll Off 0.3614)
  • Standard PRN Codes, 127, 511, 2047, 215-1, 220-1, 223-1
  • Data Rates, Modulation Type Dependent
  • Frequency Offset, 0 KHz ±20/42.5 MHz
  • Internal And External Trigger For PRN Start
  • Independent Trigger Delay Per Channel
  • AM And FM Depth Controls For AM And FM Modulation Mode