Aeronautical telemetry systems that transmit the same signal through multiple antennas from the flight vehicle suffer from severe link dropouts when the signals destructively interfere one with another at receiver. The underlying issue is a transmit array with element spacing far greater than the wavelength producing a transmit antenna pattern with significant and deep nulls. Recently, space-time coding techniques have been proven to resolve the issue for systems using linear modulations and shaped-offset quadrature shift keying (SOQPSK) modulation, a non-linear continuous phase modulation (CPM). This thesis examines application of space-time coding techniques to resolve the self-interference issue for another CPM modulation, the advanced range telemetry (ARTM) CPM. It is shown in this thesis among the two branches of space-time coding, space-time block coding (STBC) and space-time trellis coding (STTC), only the latter offers a solution for a full rate, low complexity, no hardware modification implementation. Various candidate STTCs are identified via simulation using the pair-wise error probability as a performance metric. One STTC is identified with trivial implementation costs and an error performance that is a function of code length.

International Telemetering Conference Proceedings / October 18-21, 2004 / Town & Country Resort, San Diego, California / This paper will present the results of experiments to characterize the performance of a blind, adaptive constant modulus algorithm (CMA) equalizer in simulated telemetry multipath environments. The variables included modulation method, bit rate, received signal-to-noise ratio, delay of the indirect path relative to the direct path, amplitude of the indirect path relative to the direct path, and fade rate. The main measured parameter was bit error probability (BEP). The tests showed that the equalizer usually improved the data quality in the presence of multipath.

ITC/USA 2013 Conference Proceedings / The Forty-Ninth Annual International Telemetering Conference and Technical Exhibition / October 21-24, 2013 / Bally's Hotel & Convention Center, Las Vegas, NV / Since the waveform was first developed by the Advanced Range Telemetry Program (ARTM) and adopted by the Range Commanders Council Telemetry Group (RCC/TG), receiver/demodulators for the ARTM Continuous Phase Modulation (CPM) waveform have undergone continued development by several hardware vendors to boost performance in terms of phase noise, detection performance, and resynchronization time. These same results were initially presented at the International Telemetry Conference (ITC) 2003 when hardware first became available supporting this waveform, at the time called ARTM Tier II. This paper reexamines the current state of the art performance of ARTM CPM receiver/demodulators available in the marketplace today.

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.

With National Telecommunications & Information Administration (NTIA) Advanced Wireless Services (AWS-3) auction of frequencies in the 1695-1710 MHz, 1755-1780MHz, and 2155- 2180MHz bands, users of the Aeronautical Mobile Telemetry (AMT) band from 1755- 1850MHz, known as Upper L-Band, could be greatly affected. This paper takes an initial look at how the 1755-1780MHz band will be used by the cellular carriers and presents some preliminary testing results of adjacent channel (band) interference that could be experienced by AMT users. This paper should be considered as the stepping off point for future interference discussions, required analysis, and further testing.