A new UHF narrowband satellite communications PHY layer for HPW

Abstract

The High Performance Waveform (HPW) was developed before parallel concatenated codes (PCCC) and serial concatenated codes (SCCC) were in wide use and so it makes sense to take advantage of the advancements in communication theory and processor computation speed that have taken place since its inception. In its current form, HPW transmits a Raised-Cosine Continuous Phase Modulation (1RC CPM) modulation with a trellis code that is designed to provide, with the use of a Cyclic Redundancy Check Code error detection (CRC), error free transmission over a single, narrowband UHF satellite communications channel. In this paper we present an additional set of coding and modulation schemes which take advantage of serial concatenated code (SCCC) technology to simultaneously improve throughput at the lower end of the signal-to-noise ratio (SNR) range while increasing the highest throughput at the highest SNR available on UHF satellites. The overall bit error rate and throughput of each individual modulation type is analyzed and the framework for the adaptive modulation protocol is provided. To provide for a gradual release of a newer revision of HPW, a framework for a PHY layer is provided which will allow a heterogeneous network of legacy and updated radio terminals.