Renewed military interest in HF communications has spurred the application of new technology to HF Modems. Largely, this new technology is represented by powerful microprocessors which allow the implementation of more complicated signal processing algorithms than were practical in the past. These algorithms allow vastly improved digital communications performance on the HF channel, including higher data rates, greater robustness and reduced susceptibility to interference. At high data rates (1200 to 4800 bps in a 3 kHz channel), serial (single carrier) technology has demonstrated excellent performance. However, the computational requirements for this technique are fundamentally high. Within a few years, advances in VLSI and VHSIC technology will probably provide the needed processing power in a small, low powered, inexpensive unit. Digital processing of parallel tone formats on the other hand requires significantly less computational power, and new techniques can provide improvements over past standards of HF performance. At lower bit rates (600 bps and less), correlation techniques for processing the serial waveform have been developed which provide excellent performance in the face of heavy interference as well as multipath and fading. The processing requirements for this are much less than for high rate serial algorithms mentioned above.


    Access

    Access via TIB

    Check availability in my library


    Export, share and cite



    Title :

    Advances in HF modem technology


    Additional title:

    Fortschritte in der Modem-Technologie


    Contributors:


    Publication date :

    1983


    Size :

    17 Seiten, 20 Bilder


    Type of media :

    Conference paper


    Type of material :

    Print


    Language :

    English




    Adaptive software modem technology

    Lallo, P. | Tema Archive | 2001


    Adaptive modem

    Lallo, P. | Tema Archive | 2000


    Modem ports

    Burr, A. | Online Contents | 2000



    RECONFIGURABLE UNDERWATER MODEM

    SKLIVANITIS GEORGIOS / PADOS DIMITRIS A / HERMANS JARED et al. | European Patent Office | 2024

    Free access