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-inthe-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. The T400CS eliminates the need for actual motion and distance, producing channel effects that precisely duplicate nature. This enables comprehensive test and training activities without actual flights (satellites, missiles, UAVs, targets, aircraft, etc.).

Channel effects include smooth, phase-continuous carrier and signal Doppler shift, range delay, range attenuation, fading, and noise. In addition, multiple test and/or interference signals can be generated.

A comprehensive set of frequency up/downconverters is also available, allowing signals to be generated or received at RF. The T400CS can be cable connected to devices under test, or with amplifiers, signal conditioners, and antennas, can produce short-range or long-range on-air signals.

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Local and remote control is facilitated through the T400CS client/server software architecture. Local control is provided by RT Logic client software, with remote control capabilities including Analytical Graphics, Inc.’s STK software and userwritten applications sending ASCII and binary commands over an Ethernet connection to the instrument. Users may also develop their own channel simulation profile files.

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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
 With one or more Channel Simulator cards, each emulating an uplink and/or downlink path, the T400CS generates carrier and signal Doppler shift, range delay, range attenuation, and Additive White Gaussian Noise (AWGN). These effects can be applied singly or in combination, and together precisely duplicate propagation effects encountered in LEO, MEO, HEO, and GEO satellite applications, as well as aircraft, UAV, missile, target, and range test scenarios.

When using Analytical Graphics, Inc.’s STK as the T400CS front-end software, the channel simulator produces IF/RF signals with the exact signal behavior for any scenario. STK also provides intuitive, quick, and visual development of communication link scenarios, without requiring user expertise in channel models, propagation effects, link budgets, or orbital science.

Nominal and worst-case simulation files can be used for precise playback of specific tests. These 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.

The T400CS is controlled locally and/or remotely as described earlier. In addition, the channel simulator portion of the instrument can be remotely controlled in real time when the host computer sends TCP/IP binary commands at 10 ms intervals, with the channel simulator smoothly interpolating between data points.

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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.
SPECTRUM
AND
INTERFERENCE ANALYZER
 The T400CS’s Spectrum 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 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 MHz IF Converters

Channel Simulation
  • Instantaneous Bandwidth, 40 MHz
  • Signal Doppler Shift, 0 KHz ±500 KHz, Phase-Continuous, 1 Hz Resolution
  • Carrier Doppler Shift, 0 KHz ±20 MHz, Phase-Continuous, 1 Hz Resolution
  • Range Delay, 3 µs To 1.25 s, Phase-Continuous, 1 ns Resolution
  • Range Attenuation, Up To 60 dB
  • Fading, 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, 40 dB
  • Internal And External Trigger

Signal Generation
  • Channels, 8 Per Card
  • Standard Modulation Types, BPSK, QPSK, OQPSK, 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 MHz
  • Internal And External Trigger For PRN Start
  • Independent Trigger Delay Per Channel
  • AM And FM Depth Controls For AM And FM Modulation Mode