• ANALYTICAL AND EXPERIMENTAL CHARACTERIZATION OF SOQPSK AND MULTI-H CPM IN A MULTIPATH CHANNEL

      Hill, Terrance J.; Nova Engineering, Inc. (International Foundation for Telemetering, 2001-10)
      Shaped Offset QPSK (SOQPSK) has been shown to be nearly identical in performance to Feher-patented FQPSK, which is the Advanced Range Telemetry (ATRM) program's Tier I waveform. Multi-h CPM has been selected as the ARTM Tier II waveform, because it offers 50% better spectral efficiency than the Tier I waveform. Both the Tier I and Tier II waveforms must operate in a multipath channel in order to meet the range community's telemetry requirements. This paper presents an analytical and experimental characterization of SOQPSK and Multi-h CPM in the presence of multipath. Quantitative results are presented which demonstrate the relative robustness of the ARTM Tier I and Tier II waveforms, in channels representative of a typical range environment.
    • PERFORMANCE OF SOQPSK AND MULTI-H CPM IN THE PRESENCE OF ADJACENT CHANNEL INTERFERENCE

      Hill, Terrance J.; Nova Engineering, Inc. (International Foundation for Telemetering, 2001-10)
      Multi-h CPM has been selected as the Tier II waveform for the Advanced Range Telemetry (ARTM) program, because it offers 50% better spectral efficiency than Feher-patented FQPSK, which is the Tier I waveform. Shaped Offset QPSK has been shown to be nearly identical in performance to Feher-patented FQPSK. Both the Tier I and Tier II waveforms must operate in the presence of adjacent channel interference in order to meet the range community's telemetry requirements. This paper presents an experimental characterization of SOQPSK and Multi-h CPM in the presence of adjacent channel interference, over a range of channel spacings and differential signal amplitudes. Quantitative results are presented which demonstrate the relative robustness of the ARTM Tier I and Tier II waveforms, with adjacent channel interference representative of a typical range environment.