1、BRITISH STANDARD thods of Measurement for equipment used in digital microwave radio transmission systems Part 2. Measurements on terrestrial radio-relay systems Section 11. Cross-polarization interference canceller The European Standard EN 608352-11 : 1997 has the status of a British Standard ICs 33
2、.060.30 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW BS EN 1997 1996 60835-2-11 : IEC 835-2-11 : STD-BSI BS EN b0835-2-ll-ENGL 1997 = Lb24bb7 0b24809 3b5 = BS EN 60835-2-11 : 1997 This British Standard, having been prepared under the direction of the Electrotchnical Sector
3、Board, was published under the authority of the Standards Board and comes into effect on 15 July 1997 National foreword This British Standard is the English language version of EN 608352-11 : 1997. It is identical with IEC 8352-11 : 1996. The UK participation in its preparation was entrusted to Tech
4、nical Committee EPUlOZ, Equipment used in mobile services and satellite communication systems, which has the responsibility to: - aid enquirers to understand the te - monitor related intedonal and European developments and promulgate them in the uI(. A list of organizations represented on this commi
5、ttee can be obtained on request to its secretary. Cross-references Attention is rawn to the fact that annex ZA list normative references to international publications with their corresponding European publications. The British Standards which implement these international or European publications ma
6、y be found in the BSI Standards Catalogue under the section entitled International Standars Correspondence Index, or using the Find facility of the BSI Standards Electronic Catalogue. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This
7、document comprises a front cover, an inside front cover, the EN title page, pages 2 to 20, an inside back cover and a back cover. Amendments issued since publication ID* I affected O BSI 1997 ISBN O 680 27481 O STD-BSI BS EN b0835-2-Ll-ENGL 1777 Lb24bb Ob2Li81O 087 EUROPEAN STANDARD NORME EUROPEENNE
8、 EUROPISCHE NORM EN 60835-2-1 1 January 1997 ICs 33.00.30 Descriptors: Telecommunications, radiocommunicaiom, cmUniCaiOn equipment, radio-rday systems, microwave frequencies, didtd technic, measurements, char.cterisdo8 English version Methods of measurement for equipment used in digital microwave ra
9、dio transmission systems Part 2: Measurements on terrestrial radio-relay systems Section 1 1 : Cross-polarization interference canceller (IEC 835-2-1 1 :1996) Mthodes de mesure applicables au matriel utilis pour les systmes de transmission numrique en hyperfrquence Richtfun ksystemen Partie 2: Mesur
10、es applicables aux faisceaux hertziens terrestres du brouillage de polarisation croise MeBverfahren fr Gerte in digitalen Mikrowellen-Fun kbertragungssystemen Teil 2: Messungen an terrestrischen Hauptabschnitt 1 1 : Kreuzpolarisations- I nterferent-Unterd rc ker Section 1 1 : Dispositifs dannulation
11、 (CE1 835-2-1 1 : 1996) (IEC 835-2-1 1 : 1 996) This European Standard was approved by CENELEC on 1996-1 041. CENELEC members are bound to comply witti the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any
12、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 exists in three official versions (English, French, German). A version in any other language made
13、by translation under the responsibility of a CENUK: member into its own language and notified to the Central Secretariat has the same status as the official versions. CENELK: members are the national electrotechnical committees of Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland,
14、 Ireland, Italy, Luxembourg, Netherlands, Norway. Pomigal, Spain, Sweden, Switzerland and United Kingdom. CENELEC European Committee for Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung Central Secretariat: rue de StaSS
15、art 35, B - 1050 hS8OlS (o 1997 CENELEC - All rights of exploitadon in any form and by any means reserved worldwide for CENELEC members. Ref. NO. EN 60835-2-1 11997 E Page 2 EN 60835-2-11 : 1997 Foreword The text of document 12E/263/FDIS, future edition 1 of IEC 835-2-1 18 prepared by SC 12E, Radio-
16、relay and fixed satellite communication systems, of IEC TC 12, Radiocommunications, was submitted to the IEC-CENELEC parallel vote and was approved by CENELEC as EN 60835-2-1 1 on 1996-10-01. The following dates were fixed: - latest date by which the EN has to be implemented at national level by pub
17、lication of an identical national standard or by endorsement (dop) 1 997-07-0 1 - latest date by which the national standards conflicting with the EN have to be withdrawn (daw) 1997-07-01 Annexes designated “normative“ are part of the body of the standard. In this standard, annex ZA is normative. An
18、nex ZA has been added by CENELEC. Endorsement notice The text of the International Standard IEC 835-2-1 1 : 1996 was approved by CENELEC as a European Standard without any modification. * (o * CONTENTS Clause Page 1 Scope . 4 2 Normative reference . 4 3 Static characteristics 4 3.1 C/N versus cross-
19、polarization isolation (XPi) (flat fading condition) . 4 3.2 XPI (or improvement factor) versus delay difference 6 3.3 XPI (or improvement factor) versus notch depth with dispersive signals . 7 4 Dynamic characteristics . 9 4.1 General considerations . 9 4.2 Method of measurement - . 9 4.3 Presentat
20、ion of results 9 4.4 Details to be specified . 9 Figures 1 Example of cross-polar interference canceller operation 10 2 11 Example of the structure of cross-polar interference canceller 3 Set-up for C/N versus XPI measurement 12 4 Example for C/N versus XPI measurement result 13 5 Set-up for XPI or
21、improvement factor versus delay difference measurement 14 6 Example of measurement results of XPI and of improvement factor versus delay difference 15 7 Set-up for measurement of dispersive conditions 16 Example of measurement results of XPI and improvement factor . 8 17 9 1 O Illustration of sweep
22、waveform for the measurement of dynamic characteristics Example of measurement result o dynamic characteristics . 18 19 Annex ZA (normative) Normative references to international publications with their corresponding European publications 20 STD-BSI BS EN b0835-2-11-ENGL 1777 LbZqbb9 Ob29813 7b m Pa
23、ge 4 EN 60836-2-11 : 1997 METHODS OF MEASUREMENT FOR EQUIPMENT USED IN DIGITAL MICROWAVE Par! 2: Measurements on terrestrial radio-relay systems - Section 11 : Cross-polarization interference canceller RADIO TRANSMISSION SYSTEMS - 1 Scope This section of IEC 835-2 deals with measurement for cross-po
24、larization interference cancellers (XPIC) used in digital microwave radio-relay systems. 2 Normative reference The follgwing normative document contains provisions which, through reference in this text, constitute provisions of this section of IEC 835-2. At the time of publication, the edition indic
25、ated was valid. All normative documents are subject to revision, and parties to agreements based on this section of IEC 835-2 are encouraged to investigate the possibi- lity of applying the most recent edition of .the normative document indicated below. Members of IEC and IS0 maintain registers of c
26、urrently valid International Standards. IEC 835-2-8: 1993, Methods of measurement for equipment used in digital microwave radio transmission systems - Part 2: Measurements on terrestrial radio-relay systems - Section 8: Adaptive equalizer 3 Static characteristics 3.1 C/N versus cross-polarization is
27、olation (XPl) (flat fading condition) 3.1.1 General considerations Cross-polarization isolation (XPI) as defined for two radio waves transmitted with the same power and orthogonal polarizations, is the ratio at the reception point of the power received from one of the waves to the power from the oth
28、er 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, for example 1 Oe4, resulting from the cross-polarization interference, will depend on the XPIC performance. Furthermore, it is important t
29、o 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 referred to as ordinary performance measurement) measured by increasing the value of the cross-polarization interference from a lock-in
30、state. STDmBSI BS EN bU835-2-1L-ENGL 1997 M Lb24bbS Ob24814 722 = Page 5 EN 60835-2-11 : 1997 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 the BER. At relatively high XPI values (low cros
31、s-polarization interference), there is a point where two curves (with and without the XPIC) meet (see figure 4). The point determines the operational limit of the XPIC, beyond which the XPIC cannot reduce the interference. , At low XPI values (smaller than about 10 dB), the CIN values at the outputs
32、 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 below 10 dB, a phase variation should contribute a part of the measurement. It is recommended that the worst case values of C/N be recorded
33、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 divided into main (cross-polarization main sig
34、nal) and leaky (cross-polarbation 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 signals. When C/N and XPI are both higher th
35、an about 10 dB, 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 in 3.2.2, 3.3.2 and 4.2. C/N and XPI should
36、 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 interference are switched off. Then the
37、 main signal power (s) is measured at the output port of the combiner through the calibrated band- pass 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 signal and noise are switched off, and
38、 the cross-polarization interference (i) is measured at the above-mentioned port. d) C/N and XPI are defined as follows: C/N = sin + 10 log (BCAL/B) (dB) XPI = SI where BCAL is the equivalent noise bandwidth of the bandpass filter; B is the equivalent noise bandwidth of the main signal receiver. STD
39、. BSI Page 6 EN 60836-2-11 : 1997 Cross-polarization interference levels (i) necessary for obtaining the specified BER, for example lo-, are measured by increasing interference levels from the small value for several noise levels (n) (the ordinary performance). Vary the phase of the phase shifter an
40、d 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 example of the measurement re
41、sult. 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 factor requires the XPIC to b
42、e 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 as the above- mentioned ordi
43、nary 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 XPI in dB. 3.1.4 Detail
44、s to be specified The following items should be included, as required, in the detailed equipment spec- f ication: a) main system parameters, such as bit-rate, modulation format, rollsff factor, etc.; b) pattern of test signal from a pseudo-random binary sequence generator; c) ports between which the
45、 noise and the cross-polarization interference are to be added; d) specified BER, for example e) specified C/M; 1) 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 improvement factor) versus delay dif
46、ference 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. STD.BSI BS EN bU35-2-LL-ENGL 1797 m Lb24bb Ob248Lb 5T5 Page 7 EN 60835-2-11 : 1997 3.2.2 Meth
47、od of measurement The Set-up for the measurements shown 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 (0“) is inserted into the cross-polarization main signal path, for example V-polarization. Accordingly, the delay diffe
48、rence between the cross-polarization interference path and the cross-polarization main signal path can be changed by adjusting 0,; XPI or impro- vement factor at the specified BER, for example and at the specified C/N, is measured versus the delay difference. The calibration methods of C/N and XPI a
49、re the same as in 3.1.2. An example of the measurement result is shown in figure 6, The above measurement should be repeated for the H-polarization signal inserting D, instead of D, or for the H- and the V-polarization signals inserting both O, and O, 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 speci- fication: a) ma
