• Re-Engineering PCM/FM as a Phase Modulation Scheme

      Punnoose, Ratish J.; Sandia National Laboratories (International Foundation for Telemetering, 2008-10)
      Historically, (PCM/FM) receivers have used simple detection schemes yielding low performance. Using multi-symbol detection methods, PCM/FM can be received with better error performance than either SOQPSK or multi-h CPM. We present an approximation by which PCM/FM can be reinterpreted as a phase modulation scheme, allowing the use of coherent detection techniques. This is backward compatible with existing receivers. We also present an extension by which the error performance of the approximated PCM/FM can be improved even further with no change to the spectral properties. This improved waveform can be used in systems where compatibility with existing frequency allocation schemes is required.
    • Using the GNU Radio Platform to Implement a Telemetry Receiver

      Newcomb, Gregory; Punnoose, Ratish J.; Sandia National Laboratories (International Foundation for Telemetering, 2008-10)
      GNU Radio is a flexible software radio platform that enables custom radio development. It consists of open-source signal processing blocks that can be integrated into custom applications. The Universal Software Radio Peripheral (USRP) is a hardware board that works well with the GNU Radio suite. The schematics and firmware on this board are also open-source. As such, this GNU Radio and the USRP hardware form a rapid prototype platform for software radio based telemetry receivers.