ITU-R QUESTION 2221-2000 Definition of the spectral properties of transmitter emissions《发射机发射光谱特性的定义》.pdf

1、QUESTION ITU-R 222/1*Definition of the spectral properties of transmitter emissions(2000)The ITU Radiocommunication Assembly,consideringa) that the current set of definitions of the spectral properties of transmitter emissions(necessary bandwidth, occupied bandwidth, out-of-band emission, spurious e

2、mission, etc.)contained in Article 1, Section VI, of the Radio Regulations (RR) essentially came into beingthrough the work of the World Administrative Radio Conference (Geneva, 1979);b) that the successful determination of limits in respect of those properties and the ability toperform the correspo

3、nding monitoring by means of measurements depend to a large extent on thecorrectness and clarity of all those definitions, both individually and collectively;c) that the efforts by Radiocommunication Study Group 1 to develop limits for out-of-bandemissions and to determine the boundaries between out

4、-of-band and spurious emissions have metwith difficulties, due in particular to the shortcomings of this set of definitions of spectral propertiesof emissions;d) that the existing definitions of necessary bandwidth and occupied bandwidth (RRNos. 1.152 and 1.153, respectively) are not clear, insofar

5、as these bandwidths do not show up at allin the emission spectrum unless additional calculations or additional specific measurements areperformed;e) that difficulties are also encountered when reading off out-of-band emissions, since,according to RR No. 1.144, they begin immediately at the boundarie

6、s of the necessary bandwidth,which does not appear at all in the emission spectrum;f) that difficulties are also encountered when reading off the boundaries between out-of-bandand spurious emissions, since, following the logic of the definitions of spectral properties given inRR, in 1.1 of Recommend

7、ation ITU-R SM.329 they are determined on a percentage basis withrespect to the necessary bandwidth, which does not show up at all in the emission spectrum;g) that despite the existence in RR No. 1.153 of a definition of occupied bandwidth as afunction of power (the 0.5% criterion or /2% of the mean

8、 power of the emission), it has alreadybeen over 50 years now that not one ITU-R document has given a single specific value for relativeout-of-band power /2%, other than 0.5%, for determining the occupied bandwidth for a given classof emission, while the acceptability of that very value, namely 0.5%

9、, is unsubstantiated and has notbeen corroborated for even one specific class of emission;* In the year 2009, Radiocommunication Study Group 1 extended the completion date of studies for thisQuestion.- 2 -h) that throughout this period of over 50 years, virtually no use has been made of occupiedband

10、width, as defined in RR No. 1.153, either in the frequency assignment notification andregistration process (the necessary bandwidth is notified and registered both directly and throughthe assigned frequency band) or in the monitoring process (the B26 bandwidth is monitoredat -26 dB), all of which th

11、rows doubt on the practical usefulness of occupied bandwidth as currentlydefined,decides that the following Question should be studied1 What changes could be made to the definitions of spectral properties of emissions set out inArticle 1, Section VI, of the RR in order to make those definitions, bot

12、h individually andcollectively, clearer and easy to regulate and monitor through measurements to enhance theefficient use of spectrum, and in particular:1.1 How could the concept of occupied bandwidth be effectively used in the specification ofout-of-band emissions?1.2 What would be the advantages o

13、f moving from the existing power criterion in the definitionof occupied bandwidth given in RR No. 1.153 (B ) to the level criterion (Bx) as used in thedefinition of x dB bandwidth in 1.14 of Recommendation ITU-R SM.328, and what level value(s)of x dB can be recommended for application?further decides1 that the results of the above studies should be included in (a) Recommendation(s);2 that the above studies should be completed by 2012.Category: S1