1、HTTP:/WWW.ITU.INT/DMS_PUB/ITU-R/OPB/QUE/R-QUE-SG03.227-1-2002-MSW-E.DOC 16.10.03 14.07.10QUESTION ITU-R 227-1/3*HF channel simulation(2000-2002)The ITU Radiocommunication Assembly,consideringa) that the testing and evaluation of HF modems is more cost effective when carried out undersimulated repres
2、entative ionospheric conditions;b) that detailed characteristics of the ionospheric effects on an HF channel are required inorder to simulate an HF channel accurately;c) that both narrow-band and wideband HF systems need to be tested under simulatedionospheric conditions,decides that the following Q
3、uestion should be studied1 What ionospheric situations have significant effects on an HF channel?2 What are the characteristics relevant for the simulation of a narrow-band HF channel?3 What are the characteristics relevant for the simulation of a wideband (e.g. 100 kHz)HF channel?4 What values of t
4、he channel transfer function, notably the delay power profile, arecharacteristic of the ionosphere at different locations and times?further decides1 that the available information should be prepared as new Recommendations, or as revisionsto existing Recommendations._* This Question should be brought to the attention of Radiocommunications Working Party 9C.
