BS EN 60835-2-11-1997 Methods of measurement for equipment used in digital microwave radio transmission systems - Measurements on terrestrial radio-relay systems - Cross-polarizati.pdf

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1、BRITISH STANDARD BS EN 60835-2-11: 1997 IEC835-2-11: 1996 Methods of Measurement for equipment used in digital microwave radio transmission systems Part2: Measurements on terrestrial radio-relay systems Section11: Cross-polarization interference canceller The European Standard EN60835-2-11:1997 has

2、the status of a British Standard ICS 33.060.30BSEN60835-2-11:1997 This British Standard, having been prepared under the directionof the Electrotechnical Sector Board, was published underthe authority of the Standards Board and comes intoeffect on 15 July1997 BSI09-1999 ISBN 0 580 27481 0 National fo

3、reword This British Standard is the English language version of EN60835-2-11:1997. It is identical with IEC835-2-11:1996. The UK participation in its preparation was entrusted to Technical Committee EPL/102, Equipment used in mobile services and satellite communication systems, which has the respons

4、ibility to: aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK. A lis

5、t of organizations represented on this committee can be obtained on request to its secretary. Cross-references Attention is drawn to the fact that Annex ZA list normative references to international publications with their corresponding European publications. The British Standards which implement th

6、ese international or European publications may be found in the BSI Standards Catalogue under the section entitled “International Standards Correspondence Index”, or using the “Find” facility of the BSI Standards Electronic Catalogue. A British Standard does not purport to include all the necessary p

7、rovisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages iandii, theEN title pa

8、ge, pages2 to16 and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover. Amendments issued since publication Amd. No. Date CommentsBSEN60835-2-11:1997 BSI 09-1999 i Content

9、s Page National foreword Inside front cover Foreword 2 Text of EN60835-2-11 3ii blankEUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN60835-2-11 January1997 ICS 33.060.30 Descriptors: Telecommunications, radiocommunications, communication equipment, radio-relay systems, microwave frequencies, dig

10、ital technic, measurements, characteristics English version Methods of measurement for equipment used in digital microwave radio transmission systems Part2: Measurements on terrestrial radio-relay systems Section11: Cross-polarization interference canceller (IEC835-2-11:1996) Mthodes de mesure appli

11、cables au matriel utilis pour les systmes de transmission numrique en hyperfrquence Partie2: Mesures applicables aux faisceaux hertziens terrestres Section11: Dispositifs dannulation du brouillage de polarisation croise (CEI835-2-11:1996) Meverfahren fr Gerte in digitalen Mikrowellen-Funkbertragungs

12、systemen Teil2: Messungen an terrestrischen Richtfunksystemen Hauptabschnitt11: Kreuzpolarisations- Interferenz-Unterdrcker (IEC835-2-11:1996) This European Standard was approved by CENELEC on1996-10-01. CENELEC members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate th

13、e conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Central Secretariat or to any CENELEC member. This European Standard exist

14、s in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CENELEC member into its own language and notified to the Central Secretariat has the same status as the official versions. CENELEC members are the national electr

15、otechnical committees of Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. CENELEC European Committee for Electrotechnical Standardization Comit Europen de Normalisation Elec

16、trotechnique Europisches Komitee fr Elektrotechnische Normung Central Secretariat: rue de Stassart 35, B-1050 Brussels 1997 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC members. Ref. No. EN60835-2-11:1997 EEN60835-2-11:1997 BSI 09-1999 2 Foreword The

17、 text of document12E/263/FDIS, future edition1 of IEC835-2-11, prepared by SC12E, Radio-relay and fixed satellite communication systems, of IEC TC12, Radiocommunications, was submitted to the IEC-CENELEC parallel vote and was approved by CENELEC as EN60835-2-11 on1996-10-01. The following dates were

18、 fixed: Annexes designated “normative” are part of the body of the standard. In this standard, Annex ZA is normative. Annex ZA has been added by CENELEC. Endorsement notice The text of the International Standard IEC835-2-11:1996 was approved by CENELEC as a European Standard without any modification

19、. Contents Page Foreword 2 1 Scope 3 2 Normative reference 3 3 Static characteristics 3 3.1 C/N versus cross-polarization isolation (XPI) (flat fading condition) 3 3.2 XPI (or improvement factor) versus delay difference 4 3.3 XPI (or improvement factor) versus notch depth with dispersive signals 5 4

20、 Dynamic characteristics 5 4.1 General considerations 5 4.2 Method of measurement 5 4.3 Presentation of results 6 4.4 Details to be specified 6 Annex ZA (normative) Normative references to international publications with their corresponding European publications 16 Figure 1 Example of cross-polar in

21、terference canceller operation 7 Figure 2 Example of the structure of cross-polar interference canceller 8 Figure 3 Set-up for C/N versus XPI measurement 9 Figure 4 Example for C/N versus XPI measurement result 10 Figure 5 Set-up for XPI or improvement factor versus delay difference measurement 11 F

22、igure 6 Example of measurement results of XPI and of improvement factor versus delay difference 12 Figure 7 Set-up for measurement of dispersive conditions 13 Figure 8 Example of measurement results of XPI and improvement factor 14 Figure 9 Illustration of sweep waveform for the measurement of dynam

23、ic characteristics 15 Figure 10 Example of measurement result of dynamic characteristics 15 latest date by which the EN has to be implemented at national level by publication of an identical national standard or by endorsement (dop) 1997-07-01 latest date by which the national standards conflicting

24、with the EN have to be withdrawn (dow) 1997-07-01EN60835-2-11:1997 BSI 09-1999 3 1 Scope This section of IEC835-2 deals with measurement for cross-polarization interference cancellers (XPIC) used in digital microwave radio-relay systems. 2 Normative reference The following normative document contain

25、s provisions which, through reference in this text, constitute provisions of this section of IEC835-2. At the time of publication, the edition indicated was valid. All normative documents are subject to revision, and parties to agreements based on this section of IEC835-2 are encouraged to investiga

26、te the possibility of applying the most recent edition of the normative document indicated below. Members of IEC and ISO maintain registers of currently valid International Standards. IEC835-2-8:1993, Methods of measurement for equipment used in digital microwave radio transmission systems Part2: Me

27、asurements on terrestrial radio-relay systems Section8:Adaptive equalizer. 3 Static characteristics 3.1 C/N versus cross-polarization isolation (XPI) (flat fading condition) 3.1.1 General considerations Cross-polarization isolation (XPI) as defined for two radio waves transmitted with the same power

28、 and orthogonal polarizations, is the ratio at the reception point of the power received from one of the waves to the power from the other wave, in the expected polarization of the first wave. At relatively high C/N values (low noise), the BER is essentially determined by the XPI. A constant BER, fo

29、r example10 4 , resulting from the cross-polarization interference, will depend on the XPIC performance. Furthermore, it is important to measure the lock-in performance by decreasing the value of the cross-polarization interference from a lock-out state as well as the XPIC performance (hereinafter r

30、eferred to as ordinary performance measurement) measured by increasing the value of the cross-polarization interference from a lock-in state. At relatively low C/N values (high noise), the BER is essentially determined by the noise, and the cross-polarization interference will have little effect on

31、the BER. At relatively high XPI values (low cross-polarization interference), there is a point where two curves (with and without the XPIC) meet (seeFigure 4). The point determines the operational limit of the XPIC, beyond which the XPIC cannot reduce the interference. At low XPI values (smaller tha

32、n about10dB), the C/N values at the outputs of the XPIC are sensitive to the phase relations existing within the simulated propagation model. Therefore, if the XPIC is designed to operate for XPI values below10dB, a phase variation should contribute a part of the measurement. It is recommended, that

33、 the worst case values of C/N be recorded in the results. 3.1.2 Method of measurement The set-up for the measurements is shown in Figure 3. The two modulators are driven by different pseudo-random binary signals which do not correlate with each other. After the H- and V-polarization signals are divi

34、ded into main (cross-polarization main signal) and leaky (cross-polarization interference) paths, the four path-lengths are adjusted at the inputs of the receivers to have the same static path length. Adjustable noise (n) and adjustable cross-polarization interference (i) are added to the two main s

35、ignals. When C/N and XPI are both higher than about10dB, the addition of noise and cross-polarization interference to the cross-polarization main signal path may be omitted because the effect on the measurement results is then negligible. This applies also to the methods of measurement described in3

36、.2.2, 3.3.2 and4.2. C/N and XPI should be set for both (cross-polarization and co-polarization) main signals at the demodulator input as follows. Two bandpass filters which pass the main signals without noticeable degradation may be needed to measure the noise power a) Noise and cross-polarization i

37、nterference are switched off. Then the main signal power (s) is measured at the output port of the combiner through the calibrated bandpass filter. b) Cross-polarization interference and the main signal are switched off, and the noise power (n) is measured at the above-mentioned port. c) The main si

38、gnal and noise are switched off, and the cross-polarization interference (i) is measured at the above-mentioned port. d) C/N and XPI are defined as follows: C/N=s/n+10log (B CAL /B)(dB) XPI=s/i where B CAL is the equivalent noise bandwidth of the bandpass filter; B is the equivalent noise bandwidth

39、of the main signal receiver.EN60835-2-11:1997 4 BSI 09-1999 Cross-polarization interference levels (i) necessary for obtaining the specified BER, for example10 4 , are measured by increasing interference levels from the small value for several noise levels (n) (the ordinary performance). Vary the ph

40、ase of the phase shifter and determine C/N as indicated above in order to find the worst case value. When noise and/or interference are added to both paths, C/N and XPI for both paths should have the same values, for simplicity. Results are presented by plotting C/N against XPI. Figure 4 shows an ex

41、ample of the measurement result. An XPI value at the meeting-point of the curves (with and without the XPIC) shows the operational limit. The improvement factor is the XPI difference between the performance with and without the XPIC at the specified C/N and BER. The measurement of the improvement fa

42、ctor requires the XPIC to be disabled. If this is not possible, only the performance with the XPIC is measured. The lock-in performance is measured by decreasing the value of the cross-polarization interference (i) from a lock-out state (high value of interference) of the equipment in the same way a

43、s the above-mentioned ordinary measurement. The above measurements should be carried out for either polarization signal or both polarization signals, if required. 3.1.3 Presentation of results The C/N resulting in the specified BER should be presented in decibels(dB) graphically as a function of the

44、 XPI indB. 3.1.4 Details to be specified The following items should be included, as required, in the detailed equipment specification: a) main system parameters, such as bit-rate, modulation format, roll-off factor, etc.; b) pattern of test signal from a pseudo-random binary sequence generator; c) p

45、orts between which the noise and the cross-polarization interference are to be added; d) specified BER, for example10 4 ; e) specified C/N; f) minimum required value of XPI for both the (ordinary and the lock-in performance, and minimum required improvement factor, if applicable. 3.2 XPI (or improve

46、ment factor) versus delay difference 3.2.1 General considerations The performance of the XPICs is generally sensitive to the delay difference between the cross-polarization interference path and the cross-polarization main signal path. 3.2.2 Method of measurement The set-up for the measurements show

47、n in Figure 5. This set-up is the same as the one for C/N versus XPI measurement in Figure 3 except that a variable delay line (D V ) is inserted into the cross-polarization main signal path, for example V-polarization. Accordingly, the delay difference between the cross-polarization interference pa

48、th and the cross-polarization main signal path can be changed by adjusting D V ; XPI or improvement factor at the specified BER, for example10 4and at the specified C/N, is measured versus the delay difference. The calibration methods of C/N and XPI are the same as in3.1.2. An example of the measure

49、ment result is shown in Figure 6, The above measurement should be repeated for the H-polarization signal inserting D Hinstead of D V , or for the H- and the V-polarization signals inserting both D Vand D H , if required. 3.2.3 Presentation of results XPI or the improvement factor, if applicable, should be presented graphically for a specified BER as a function of the delay difference. 3.2.4 Details to be specified The following items should be included, as required, in the detailed equipment specification: a) main system