• A COMPARISON OF ADAPTIVELY EQUALIZED PCM/FM, SOQPSK, AND MULTI-H CPM IN A MULTIPATH CHANNEL

      Hill, Terrance; Geoghegan, Mark; Nova Engineering Inc. (International Foundation for Telemetering, 2002-10)
      It is widely recognized that telemetry channels, particularly airborne channels, are afflicted by multipath propagation effects. It has also been shown that adaptive equalization can be highly effective in mitigating these effects. However, numerous other factors influence the behavior of adaptive equalization, and the type of modulation employed is certainly one of these factors. This is particularly true on modulations which exhibit different operating bandwidths. In this paper, we will examine the effect multipath and adaptive equalization for three modulation techniques which are either already in use, or have been proposed, for airborne telemetry.
    • IMPLEMENTATION AND PERFORMANCE OF A HIGHSPEED, VHDL-BASED, MULTI-MODE ARTM DEMODULATOR

      Hill, Terrance; Geoghegan, Mark; Hutzel, Kevin; Nova Engineering Inc. (International Foundation for Telemetering, 2002-10)
      Legacy telemetry systems, although widely deployed, are being severely taxed to support the high data rate requirements of advanced aircraft and missile platforms. Increasing data rates, in conjunction with loss of spectrum have created a need to use available spectrum more efficiently. In response to this, new modulation techniques have been developed which offer more data capacity in the same operating bandwidth. Demodulation of these new waveforms is a computationally challenging task, especially at high data rates. This paper describes the design, implementation and performance of a high-speed, multi-mode demodulator for the Advanced Range Telemetry (ARTM) program which meets these challenges.