1、QUESTION ITU-R 145-2/5*,*Characteristics required for high-speed data transmissionover HF radio circuits(1990-1999-2007)The ITU Radiocommunication Assembly,consideringa) that an increasing demand is noted for high-speed data transmission over HF radio circuitsand further increase in such demand may
2、be expected;b) that recent radiocommunication technologies and operational techniques are leadingto systems having greatly improved bandwidth efficiency, i.e. a larger capacity in bits per secondper unit bandwidth;c) that it is desirable that the effects of the random variations and disturbances in
3、thepropagation medium be the ultimate factors governing the performance obtainable with suchsystems,decides that the following Questions should be studied1 What performance characteristics are required for data transmission by HF radio systems?2 What is the maximum achievable data rate in the HF rad
4、io channel for the desired biterror ratio?3 How can error-correction coding, time interleaving, in-band frequency diversity andother techniques can be used to achieve the desired error probability?further decides1 that the results of the above study should be included in one or more Recommendation(s)and/or Report(s);2 that the above study should be completed by 2010.NOTE 1 See Recommendations ITU-R F.436 and ITU-R F.763.Category: S2_* This Question should be brought to the attention of Radiocommunication Study Group 8 (WP 8B).* Former Question ITU-R 145-2/9.