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PARAMETER CHARACTERIZATION ON A TELEMETRY CHANNEL INCLUDING THE EFFECTS OF THE SPECULAR RAYDye, Ricky G., Horne, Lyman D. 11 1900 (has links)
International Telemetering Conference Proceedings / October 30-November 02, 1995 / Riviera Hotel, Las Vegas, Nevada / The aeronautical channel model is a good candidate for modeling the effects of
multipath interference of telemetry signals on test ranges. The aeronautical fading
channel model is parameterized by the signal to noise ratio, the Doppler shift and time
delay between the specular and direct components, the specular to direct power ratio,
the direct to diffuse power ratio, and the bandwidth of the multipath fading process.
Segments of weighting signal data measured during a test at Tyndall AFB provide
data which can be used to determine typical values of the above parameters in a
variety of telemetering environments. In this paper, the set of parameters which most
closely model the actual telemetry channel using the Tyndall data is determined.
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SHF MULTIPATH CHANNEL MODELING RESULTSRice, Michael, Lei, Qiang 10 1900 (has links)
ITC/USA 2005 Conference Proceedings / The Forty-First Annual International Telemetering Conference and Technical Exhibition / October 24-27, 2005 / Riviera Hotel & Convention Center, Las Vegas, Nevada / This paper presents the results of land-based SHF channel modeling experiments. Channel
modeling data were collected at Edwards AFB, California at S-Band, X-Band and Ku-band.
Frequency domain analysis techniques were used to evaluate candidate channel models. A
graphical user interface (GUI) was developed to search for the optimum channel parameters. The
model parameters corresponding to different frequencies were compared for multipath events
captured at approximately the same locations. A general trend was observed where the magnitude
of the first multipath reflection decreased as frequency increased and the delay remained
relatively unchanged.
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AIRBORNE/SHIPBORNE PSK TELEMETRY DATA LINKCARLSON, JOHN R., SCHMIDT, ARLEN 11 1900 (has links)
International Telemetering Conference Proceedings / November 04-07, 1991 / Riviera Hotel and Convention Center, Las Vegas, Nevada / This paper describes the design considerations and methodology applied to solve the practical problems posed in the creation of a high bit rate telemetry relay system and specifically the techniques implemented to enhance signal to noise performance under adverse operational conditions.
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CMA BLIND EQUALIZER FOR AERONAUTICAL TELEMETRYXingwen, Ding, Wantao, Zhai, Hongyu, Chang, Ming, Chen 11 1900 (has links)
In aeronautical telemetry, the multipath interference usually causes significant performance
degradation. As the bit rate of telemetry systems increases, the impairments of multipath
interference are more serious. The constant modulus algorithm (CMA) blind equalizer is effective
to mitigate the impairments of multipath interference. The CMA adapts the equalizer coefficients
to minimize the deviation of the signal envelope from a constant level. This paper presents the
performances of the CMA blind equalizer applied for PCM-FM, PCM-BPSK, SOQPSK-TG and
ARTM CPM in aeronautical telemetry.
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Modelling of Mobile Fading Channels with Fading Mitigation Techniques.Shang, Lei, lei.shang@ieee.org January 2006 (has links)
This thesis aims to contribute to the developments of wireless communication systems. The work generally consists of three parts: the first part is a discussion on general digital communication systems, the second part focuses on wireless channel modelling and fading mitigation techniques, and in the third part we discuss the possible application of advanced digital signal processing, especially time-frequency representation and blind source separation, to wireless communication systems. The first part considers general digital communication systems which will be incorporated in later parts. Today's wireless communication system is a subbranch of a general digital communication system that employs various techniques of A/D (Analog to Digital) conversion, source coding, error correction, coding, modulation, and synchronization, signal detection in noise, channel estimation, and equalization. We study and develop the digital communication algorithms to enhance the performance of wireless communication systems. In the Second Part we focus on wireless channel modelling and fading mitigation techniques. A modified Jakes' method is developed for Rayleigh fading channels. We investigate the level-crossing rate (LCR), the average duration of fades (ADF), the probability density function (PDF), the cumulative distribution function (CDF) and the autocorrelation functions (ACF) of this model. The simulated results are verified against the analytical Clarke's channel model. We also construct frequency-selective geometrical-based hyperbolically distributed scatterers (GBHDS) for a macro-cell mobile environment with the proper statistical characteristics. The modified Clarke's model and the GBHDS model may be readily expanded to a MIMO channel model thus we study the MIMO fading channel, specifically we model the MIMO channel in the angular domain. A detailed analysis of Gauss-Markov approximation of the fading channel is also given. Two fading mitigation techniques are investigated: Orthogonal Frequency Division Multiplexing (OFDM) and spatial diversity. In the Third Part, we devote ourselves to the exciting fields of Time-Frequency Analysis and Blind Source Separation and investigate the application of these powerful Digital Signal Processing (DSP) tools to improve the performance of wireless communication systems.
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