1、 ETSI TR 103 053 V1.1.1 (2014-09) Fixed Radio Systems; Parameters affecting the Signal-to-Noise Ratio (SNR) and the Receiver Signal Level (RSL) threshold in point-to-point receivers; Theory and practice floppy3TECHNICAL REPORT ETSI ETSI TR 103 053 V1.1.1 (2014-09) 2Reference DTR/ATTM-04015 Keywords
2、noise, point-to-point, receiver ETSI 650 Route des Lucioles F-06921 Sophia Antipolis Cedex - FRANCE Tel.: +33 4 92 94 42 00 Fax: +33 4 93 65 47 16 Siret N 348 623 562 00017 - NAF 742 C Association but non lucratif enregistre la Sous-Prfecture de Grasse (06) N 7803/88 Important notice The present doc
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7、tion of ETSI. The copyright and the foregoing restriction extend to reproduction in all media. European Telecommunications Standards Institute 2014. All rights reserved. DECTTM, PLUGTESTSTM, UMTSTMand the ETSI logo are Trade Marks of ETSI registered for the benefit of its Members. 3GPPTM and LTE are
8、 Trade Marks of ETSI registered for the benefit of its Members and of the 3GPP Organizational Partners. GSM and the GSM logo are Trade Marks registered and owned by the GSM Association. ETSI ETSI TR 103 053 V1.1.1 (2014-09) 3Contents Intellectual Property Rights 4g3Foreword . 4g3Modal verbs terminol
9、ogy 4g3Introduction 4g31 Scope 5g32 References 5g32.1 Normative references . 5g32.2 Informative references 5g33 Definitions, symbols and abbreviations . 6g33.1 Definitions 6g33.2 Symbols 6g33.3 Abbreviations . 6g34 Proposed technical parameters . 7g34.1 Forward error correction code 7g34.2 Noise fig
10、ure and RX duplexer loss . 10g34.3 Channel Separation (ChS) 11g34.4 Phase noise . 11g34.5 Non-linear distortion 15g34.6 Internal distortion . 15g34.7 Industrial margin 16g34.8 Evaluation of the RSL 16g35 Conclusion 17g3Annex A: Illustration of Signal to Noise degradation . 18g3Annex B: Evaluation of
11、 the RSL spreadsheet . 21g3History 22g3ETSI ETSI TR 103 053 V1.1.1 (2014-09) 4Intellectual Property Rights IPRs essential or potentially essential to the present document may have been declared to ETSI. The information pertaining to these essential IPRs, if any, is publicly available for ETSI member
12、s and non-members, and can be found in ETSI SR 000 314: “Intellectual Property Rights (IPRs); Essential, or potentially Essential, IPRs notified to ETSI in respect of ETSI standards“, which is available from the ETSI Secretariat. Latest updates are available on the ETSI Web server (http:/ipr.etsi.or
13、g). Pursuant to the ETSI IPR Policy, no investigation, including IPR searches, has been carried out by ETSI. No guarantee can be given as to the existence of other IPRs not referenced in ETSI SR 000 314 (or the updates on the ETSI Web server) which are, or may be, or may become, essential to the pre
14、sent document. Foreword This Technical Report (TR) has been produced by ETSI Technical Committee Access, Terminals, Transmission and Multiplexing (ATTM). Modal verbs terminology In the present document “shall“, “shall not“, “should“, “should not“, “may“, “may not“, “need“, “need not“, “will“, “will
15、not“, “can“ and “cannot“ are to be interpreted as described in clause 3.2 of the ETSI Drafting Rules (Verbal forms for the expression of provisions). “must“ and “must not“ are NOT allowed in ETSI deliverables except when used in direct citation. Introduction Digital Fixed Radio Systems (DFRS) had be
16、en historically specified in a relatively large number of specific European Norms produced by ETSI. These ENs were prepared separately and, even if the list of standardized parameters was common to all these ENs, their specific values were defined on a case-by-case basis. The content of the old Poin
17、t-to-Point ENs was further transferred into the multipart standard EN 302 217 i.4 while in a first time most of the parameters values were kept unchanged. As a consequence the RSL figures provided in earlier versions up to V1.4.1 of EN 302 217-2-2 i.2 are an array of values proposed at different tim
18、es and corresponding to different technology situations. ETSI ETSI TR 103 053 V1.1.1 (2014-09) 51 Scope The present document provides guidance for the definition of a full set of rationalized RSL values based on the most recent technological state-of-the-art and determined using a common set of rule
19、s for all P-P systems within the scope of EN 302 217 i.4. As part of the rationalization effort of EN 302 217 i.4, the present document proposes technical parameters to be used as basis in the calculation of the RSL figures. 2 References References are either specific (identified by date of publicat
20、ion and/or edition number or version number) or non-specific. For specific references, only the cited version applies. For non-specific references, the latest version of the reference document (including any amendments) applies. Referenced documents which are not found to be publicly available in th
21、e expected location might be found at http:/docbox.etsi.org/Reference. NOTE: While any hyperlinks included in this clause were valid at the time of publication, ETSI cannot guarantee their long term validity. 2.1 Normative references The following referenced documents are necessary for the applicati
22、on of the present document. Not applicable. 2.2 Informative references The following referenced documents are not necessary for the application of the present document but they assist the user with regard to a particular subject area. i.1 ETSI EN 302 217-1: “Fixed Radio Systems; Characteristics and
23、requirements for point-to-point equipment and antennas; Part 1: Overview and system-independent common characteristics“. i.2 ETSI EN 302 217-2-2: “Fixed Radio Systems; Characteristics and requirements for point-to-point equipment and antennas; Part 2-2: Digital systems operating in frequency bands w
24、here frequency co-ordination is applied; Harmonized EN covering the essential requirements of article 3.2 of the R Characteristics and requirements for point-to-point equipment and antennas“. i.5 IEEE 802.16: “IEEE Standard for Air Interface for Broadband Wireless Access Systems“. i.6 Recommendation
25、 ITU-R F.1101: “Characteristics of digital fixed wireless systems below about 17 GHz“. ETSI ETSI TR 103 053 V1.1.1 (2014-09) 63 Definitions, symbols and abbreviations 3.1 Definitions For the purposes of the present document, the following terms and definitions apply: air interface interoperability:
26、requirement by which DFRS terminals from different manufacturer can be connected inside the same radio systems NOTE: It requires standardization of the physical radio layer (e.g. modulation format, digital codings, synchronization procedures, etc.) and part or all of the higher network layers protoc
27、ols. digital fixed radio systems: comprise the whole family of Point-to-point (P-P), Point-to-multipoint (P-MP) and Multipoint-to-multipoint (MP-MP) radio equipment (see note 2), which may be used in fixed locations as part of public or private core or access networks (see note 3) NOTE 1: It is equi
28、valent to the ITU-R definition of Fixed Wireless Systems (FWS) and comprises Fixed Wireless Access (FWA) systems and, in specific cases, their optional extension to Nomadic Wireless Access (NWA). NOTE 2: The two latter generically identified as Multipoint (MP) systems. NOTE 3: Analogue systems are n
29、o longer implemented; therefore, for the purpose of the present document only digital applications are identified as DFRS. essential phenomenon: radio frequency phenomenon related to the essential requirements under article 3.2 of the R they are necessary parameters for defining the RSL threshold. I
30、n common practice, the “system noise figure“ is intended as the overall system noise figure composed by the sum of the noise figure of the receiver chain (evaluated from LNA input to the demodulator input) plus the RX side branching loss (duplexer insertion loss). For a detailed analysis in view of
31、defining a “reference“ value for comparison, these two components should be separately analysed. Practical low noise amplifiers and associated receiver chains for high frequencies have higher noise figure than practical LNAs for lower frequencies. The variation is assumed to be continuously increasi
32、ng with the frequency. However, the technology impact (mostly for size problems) for lower bands implies that the frontend noise figure may not drop as low as the single active components would permit. Similarly, also RX side duplexer are subject to a number of factors affecting their losses (evalua
33、ted, according to EN 302 217-1 i.1, at the reference point B or the reference point C when they are coincident). Examples of such factors are: Technology: filters may be realized with many technologies for reducing their size and/or their losses and/or their cost. In particular, the change of techno
34、logy for size constraint tends to compress the variation of the natural increasing of loss with the frequency. Channel arrangement: in a number of bands, different channel arrangements with different TX/RX duplex separations are used in different countries. Even if, in most cases, the difference in
35、losses is not a major issue, this fact should be here mentioned and kept in mind. Configuration: according to the user needs, different protection configuration or number of channels may be connected to the same antenna port. This implies that the same equipment may be connected to different types o
36、f duplexers (e.g. from the simplest 1+0 configuration, to the 1+1 hot-standby, to the N+1 of trunk applications); also outdoor or full indoor mount implies differences from the duplexer point of view. For providing a homogeneous guidance and the “total reference noise figure“, the duplexer losses ar
37、e defined according the following assumptions: a) The technology should not result in inhomogeneous figures. The optimization of cost and performance is a common target; therefore, this should imply that in each band the same technology is likely to be used. b) For the channel arrangement variants o
38、nly the lowest duplex separation, implying the expected highest losses in the band, are considered. c) For the configuration only the simplest 1+0 configuration (generally available for all equipment on the market) are considered (see note). NOTE: Also in link budget analysis the more complex and lo
39、ssy configurations are often taken into account as “additional losses“ over the 1+0 configuration; therefore, this seems the best choice for a homogeneous definition of “reference values“. ETSI ETSI TR 103 053 V1.1.1 (2014-09) 11Table 3 contains the band-by-band information and the suggested “refere
40、nce values“ for the total noise figure, without industrial margin. Table 3: Typical values for BER threshold determination Frequency Band (GHz) “Reference“ Total Noise Figure Duplexer Loss + Noise figure (dB) 1,5 (1,350 to 1,517) 4 2 (2,025 to 2,290) 4 L4 (3,4 to 4,2) 5 U4 (4,4 to 5) 5 L6 (5,925 to
41、6,425) 5 U6 (6,425 to 7,125) 5 7 (7,110 to 7,725) 5 8 (7,725 to 8,500) 5 10,5 (10 to 10,68) 5 11 (10,7 to 11,7) 5 13 (12,7 to 13,25) 5 15 (14,4 to 15,35) 5 18 (17,7 to 19,7) 6 23 (21,2 to 23,6) 6 26 (24,5 to 26,5) 7 28 (27,5 to 29,5) 7 32 (31,8 to 33,4) 7 38 (37 to 39,5) 8 42 (40,5 to 43,5) 8 50 (48
42、,5 to 50,2) 9 52 (51,4 to 52,6) 10 55 (55,78 to 57,0) 10 70 (71 to 76) 13 80 (81 to 86) 13 4.3 Channel Separation (ChS) The thermal noise density at 300 K is -174 dBm/Hz. For an errorless communication link, the signals RSL is expected to be at a certain level above the integrated noise over the ban
43、dwidth of the signal. A receiver that was optimally designed for a signal with root-raised-cosine (RRC) shaping filter has an RRC also as the channel filter. The Noise Effective Bandwidth (NEB) of an RRC filter is narrower than the ChS by a rolloff factor of the RRC which is assumed to be 90 % of th
44、e ChS. EXAMPLE: A system with ChS of 28 MHz has NEB of 28 MHz 0,9 = 25,2 MHz. The integrated thermal noise over 25,2 MHz is equal to -174 + 10 log10 (25,2 106) dBm = -100 dBm. 4.4 Phase noise The calculation of the phase noise contribution can be estimated with a model based on some simple assumptio
45、ns on oscillator phase noise and carrier recovery loop. Both topics could be more deeply detailed but the following simple assumptions are taken: the shape of the round trip phase noise of the complete system drops 20 dB / decade; the carrier recovery loop is based on a type II second order PLL. The
46、se assumptions are reasonably taken as common practice. ETSI ETSI TR 103 053 V1.1.1 (2014-09) 12In order to perform the phase noise contribution calculation, the following four parameters are requested: Kloand fmfor the end-to-end phase noise; fcand Fsrespectively for recovery loop bandwidth and sym
47、bol rate. Assuming that the phase noise shape is described as in the equation below: 2)(fKfLlo= The offset frequency fmand the associated phase noise value Kloidentify the curve shown in figure 3. g3vlb2570 Sample 1-160-150-140-130-120-110-100-90-80-701 10 100 1000Offset kHzPhase Noise(dBc/Hz)85C 25
48、85-40C 258525C 2585Figure 3: Offset frequency fmand its associated phase noise value KloIf the end-to-end phase noise at fm frequency offset is XdBthen: 10/210XdBmlofK = The carrier recovery loop can be modelled as depicted in figure 4. Figure 4: Simplified model for the carrier recovery loop where
49、Lpf(f), Fpll(f) and LO(f) are the phase transfer functions of demodulation low pass filter, PLL loop filter and vco. These transfer functions are respectively listed below: 2/21)(FsfjKlfLpf+=ETSI ETSI TR 103 053 V1.1.1 (2014-09) 13fjfzfjKgfFpll22)(+= fjKvcofLO21)( = The open loop gain results: )()()()( fLOfFpllfLpffGloop = and the closed loop transfer function is: )(1)()(fGloopfLfG+= The phase variation transfer function of such recovery loop is a high pass filter with slope of 40 dB / decade from 0 Hz to the frequency fc
