This Recommendation specifies the typical RF characteristics of advanced digital HF systems for use in sharing studies for two types of emerging advanced digital HF systems, token passing protocols and wideband modems. Wideband modems are further subdivided into two major systems, multichannel operations and Digital Radio Mondiale operations. A table of characteristics within the Annex to this Recommendation provides a summary of the values needed for sharing studies.
ITU-R F.1821-2007 Referenced Document
ITU-R BS.1514-1 System for digital sound broadcasting in the broadcasting bands below 30 MHz
ITU-R F.339 Bandwidths, signal-to-noise ratios and fading allowances in HF fixed and land mobile radiocommunication systems*， 2013-02-01 Update
ITU-R F.763-5 Data Transmission over HF Circuits Using Phase Shift Keying or Quadrature Amplitude Modulation
ITU-R F.1821-2007 history
2007ITU-R F.1821-2007 Characteristics of advanced digital high frequency (HF) radiocommunication systems