ITU-R REPORT SA 2164-2009 Compatibility between the meteorological satellite and the fixed services in the band 7 850-7 900 MHz《频段在7 850-7 900 MHz固定业务和气象卫星之间的兼容性》.pdf

1、 Report ITU-R SA.2164(09/2009)Compatibility between the meteorological satellite and the fixed services in the band 7 850-7 900 MHzSA SeriesSpace applications and meteorologyii Rep. ITU-R SA.2164 Foreword The role of the Radiocommunication Sector is to ensure the rational, equitable, efficient and e

2、conomical use of the radio-frequency spectrum by all radiocommunication services, including satellite services, and carry out studies without limit of frequency range on the basis of which Recommendations are adopted. The regulatory and policy functions of the Radiocommunication Sector are performed

3、 by World and Regional Radiocommunication Conferences and Radiocommunication Assemblies supported by Study Groups. Policy on Intellectual Property Right (IPR) ITU-R policy on IPR is described in the Common Patent Policy for ITU-T/ITU-R/ISO/IEC referenced in Annex 1 of Resolution ITU-R 1. Forms to be

4、 used for the submission of patent statements and licensing declarations by patent holders are available from http:/www.itu.int/ITU-R/go/patents/en where the Guidelines for Implementation of the Common Patent Policy for ITU-T/ITU-R/ISO/IEC and the ITU-R patent information database can also be found.

5、 Series of ITU-R Reports (Also available online at http:/www.itu.int/publ/R-REP/en) Series Title BO Satellite delivery BR Recording for production, archival and play-out; film for television BS Broadcasting service (sound) BT Broadcasting service (television) F Fixed service M Mobile, radiodetermina

6、tion, amateur and related satellite services P Radiowave propagation RA Radio astronomy RS Remote sensing systems S Fixed-satellite service SA Space applications and meteorology SF Frequency sharing and coordination between fixed-satellite and fixed service systems SM Spectrum management Note: This

7、ITU-R Report was approved in English by the Study Group under the procedure detailed in Resolution ITU-R 1. Electronic Publication Geneva, 2010 ITU 2010 All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without written permission of ITU. Rep. ITU-R SA.2164

8、1 REPORT ITU-R SA.2164 Compatibility between the meteorological satellite and the fixed services in the band 7 850-7 900 MHz (2009) TABLE OF CONTENTS Page 1 Introduction 2 2 Background . 2 3 Meteorological satellite system description . 3 4 Fixed service system assumptions 5 5 Interference assessmen

9、t to fixed service receivers . 6 6 Interference assessment to meteorological earth station receivers . 14 7 Technical summary and discussion 20 7.1 Potential of interference into fixed service receivers . 20 7.2 Potential of interference into meteorological earth station receivers . 20 8 Conclusions

10、 21 2 Rep. ITU-R SA.2164 1 Introduction World Radiocommunication Conference 2012 (WRC-12) Agenda item 1.24 considers the extension of the existing primary allocation to the meteorological-satellite service in the band 7 750-7 850 MHz to the band 7 850-7 900 MHz. Applications in the meteorological sa

11、tellite service are limited to non-geostationary satellites transmitting in the space-to-Earth direction. Although the same service applications are affected as in the current allocation 7 750-7 850 MHz, and noting that meteorological systems already share this band successfully with the fixed servi

12、ce, this assessment covers all potential modes of operation and compatibility aspects for the potential extension to 7 850-7 900 MHz. 2 Background Several polar orbiting meteorological satellite systems are currently using or planning to use the band 7 750-7 850 MHz. The main mode of operation is da

13、ta transmission to a dedicated earth station in high latitudes, such as Svalbard on Spitsbergen, Norway. One of the systems operates in a multi-user mode transmitting meteorological data to a number of user stations, operated mainly by national weather services. Table 1 shows typical data of the 3 r

14、epresentative systems EUMETSAT polar-orbiting meteorological satellite system (Metop), United States National Polar-orbiting Operational Environmental Satellite System (NPOESS) and the second generation of polar-orbital meteorological satellites of China (FY-3). The measurements and observations per

15、formed by those MetSat systems, provide data used in the areas of operational meteorology, climate monitoring, and detection of global climatic changes, having significantly improved operational meteorology, in particular the Numerical Weather Prediction (NWP). Determined by the users of those data,

16、 namely the National Weather Services, next generation of these non-geostationary MetSat systems will have to provide continuity to the measurements and observations performed by the current systems. Furthermore, these future systems will have to perform additional measurements and observations of m

17、eteorological and climate parameters with higher resolution, resulting in much higher data rates and bandwidth as required today. The necessary bandwidth for the downlink of the raw instrument data for future non-geostationary MetSat systems that fulfil those requirements for further enhanced data i

18、n the area of operational meteorology and climatology would be up to 150 MHz. Rep. ITU-R SA.2164 3 TABLE 1 Characteristics of some meteorological satellite system applications in the band 7 750-7 850 MHz Metop NPP NPOESS FY-3 Carrier frequency (MHz) 7800 7812 7834 7775 Orbit height (km) 817 824 828

19、836 Maximum bandwidth (MHz) 63.0 30 30.8 45.0 Modulation scheme QPSK QPSK SQPSK QPSK Satellite EIRP (dBW) 13.5 12.9 20.4 19.6 Earth station antenna diameter (m) 10.0 3.0 2.0 3.0 Earth station antenna gain (dBi) 55.2 44.9 41.7 45.2 Maximum PFD on surface of earth (dB(W/m2 4 kHz) 165.9 162.9 155.6 158

20、.1 Margin with respect to PFD limit (dB) 13.9 10.9 3.6 6.1 The desired extension of the MetSat allocation into the band 7 850-7 900 MHz would only affect the same radiocommunication services, namely the FIXED and MOBILE (except aeronautical mobile) service, like in the band 7 750-7 850 MHz where the

21、 METSAT service is already allocated on a co-primary basis limited to NGSO applications. Compatibility was already demonstrated in preparation for (WRC-97) where the allocation to the MetSat in the band 7 750-7 850 MHz was originally added to the table of allocations in Article 5 of the Radio Regula

22、tions (RR). Studies conducted prior to (WRC-97) concluded that more than 13 dB of margin were available to protect fixed service systems operating with worst case azimuths along the sub-satellite track. In particular the interference impact on the fixed and mobile service from the downlink of a pola

23、r-orbiting MetSat system like Post-EPS to its dedicated earth station is very limited as such an earth station is deployed at high northern (Svalbard, Spitsbergen) or southern latitudes (McMurdo, Troll, OHiggens, Antarctica) in order to avoid blind orbits in which the stored instrument data of an en

24、tire orbit cannot be received. For other applications such as the dissemination of data directly to the user (so-called direct read-out), for which the number of reception stations could be higher and which could be located anywhere, the sharing situation needs to be studied. Currently there are two

25、 systems (NPP and NPOESS of NOAA) planned for such type of operations which requires around 30 MHz of contiguous spectrum. For another system (Fengyun-3 or FY-3 from China), the dissemination of data is planned to be restricted mainly to the territory of China. The first satellite FY-3A was launched

26、 in 2008. The objective of this assessment is to provide a comprehensive overview of the impact all potential future meteorological system applications may have on fixed service installations. 3 Meteorological satellite system description The next generation meteorological satellite system design su

27、ch as Post-EPS will focus on wideband data dump transmissions into few main earth stations at high latitudes, such as Svalbard, Kiruna, Fairbanks, Troll, McMurdo and OHiggens. The systems are expected to have bandwidth requirements up to 150 MHz. These high bandwidth requirements are primarily due t

28、o transmission of data from high resolution sensors and other instruments. 4 Rep. ITU-R SA.2164 All currently operated and planned systems are deployed in non-geostationary orbits with typical orbital heights between 800 and 850 km and an inclination of around 98 and the same will apply for future s

29、ystems. Earth stations in very high northern and southern latitudes are preferred in order to maximize contact time between the satellites and the earth stations. Transmissions are typically only affected when in line of sight of the corresponding earth station at elevation angles in excess of 5. To

30、 date, two systems are planned to operate in a multi user mode with the transmitter continuously active. Power flux densities of systems using this frequency band for stored instrument data dump transmissions are typically significantly below the PFD limits but for the compatibility assessments, the

31、 satellites will be assumed to operate at the PFD limit. Antenna types are currently cardioid but for the higher data rates parabolic antennas may be needed. The most likely modulation technique for such high data rates is 8-PSK. Figure 1 shows the assumed antenna gains for cardioid antennas based o

32、n currently implemented antennas as well as parabolic antennas likely to be used for future systems. FIGURE 1 Meteorological satellite antenna gains assumed for simulations Report SA.2164-011050510152025300 5 10 15 20 25 30 35 40 45 50 55 60 65Expected Post-EPS and multi-user mode antenna gainAverag

33、e gain (Rec. ITU-R F.1245) for a 0.3 m parabolic antennaAntenna gain(dBi)Nadir off-axis angle (degrees)Earth station receiving antenna diameters can in principle vary between 2 m for low data rate direct read-out reception in multi-user modes and 13 m for stored instrument data dump reception earth

34、stations. Table 2 shows link budget examples for future meteorological satellite systems covering all potential operating modes and antenna types. For the stored instrument data dump reception station, the currently used antenna in Svalbard with a diameter of 10 m was selected. Rep. ITU-R SA.2164 5

35、TABLE 2 Link budget examples for future meteorological satellite systems operating around 7.8 GHz System A System B System C Carrier frequency (MHz) 7 825 7 825 7 825 Orbit height (km) 830 830 830 Maximum bandwidth (MHz) 150 150 150 Minimum elevation angle (degrees) 5 5 5 Modulation scheme 8-PSK QPS

36、K 8-PSK Satellite RF power in dBW (dBW) 23.0 24.8 3.8 Satellite antenna type cardioid cardioid parabolic Maximum satellite antenna gain (dBi) 6.0 6.0 25.2 Satellite EIRP (dBW) 29.0 30.8 29.0 Distance satellite Earth station for 5 (km) 2 848 2 848 2 848 Free space propagation loss (dB) 179.4 179.4 17

37、9.4 Rain margin for 99.9% availability (dB) 2.2 2.2 2.2 Short term downlink loss (dB) 181.6 181.6 181.6 Earth station antenna diameter (m) 10.0 2.2 4.0 Earth station antenna gain (dBi) 55.3 42.1 47.3 Short term signal power level at receiver input (dBW) 97.4 108.7 105.3 Receiver system temperature (

38、K) 180 180 180 Maximum PFD on surface of earth (dB(W/m2 4 kHz) 152.0 152.0 152.0 Margin with respect to PFD limit (dB) 0.0 0.0 0.0 Receiver noise power density (dBW/Hz) 206.0 206.0 206.0 Signal to noise density ratio (C/N0) Short-term (dB/Hz) 108.7 97.3 100.8 Required Eb/N0(with coding gain if appli

39、cable) (dB) 13.0 7.5 13.0 System margin Short-term (dB) 9.2 5.1 1.2 4 Fixed service system assumptions Recommendation ITU-R F.758 contains relevant information on fixed service characteristics in the band 7 850-7 900 MHz. Annex 1 of that Recommendation provides information on basic considerations in

40、 the development of sharing criteria, and Tables 12 and 13 of Annex 2 provide characteristics of typical FS systems in this band. Table 44 of Recommendation ITU-R F.758 specifies minimum antenna gains. Table 3 contains the relevant system characteristics extracted from Annex 2 of Recommendation ITU-

41、R F.758. The methods for analysing interference between non-geostationary satellites and the FS are described in Recommendation ITU-R F.1108. This Recommendation makes also reference to related Recommendations ITU-R F.1094, ITU-R F.1668 and ITU-R F.1703, which have been taken into account. 6 Rep. IT

42、U-R SA.2164 TABLE 3 FS system parameters for frequency sharing around 7.8 GHz Frequency band (GHz) 7.1-8.5 7.725-8.275 Modulation 64-QAM 128-QAM Capacity (Mbit/s) 45 90 135 155 Channel spacing (MHz) 10 20 30 29.65 Antenna gain range (dBi) 37-49 37-49 37-49 37-45 Feeder/multiplexer loss (minimum) (dB

43、) 0 0 0 Tx:4.6 Rx:4.8 Antenna type Dish Dish Dish Dish Maximum Tx output power (dBW) +3 +3 +3 +3 E.i.r.p. range (dBW) 40-52 40-52 40-52 40-43.4 Mean e.i.r.p. density range (dBW/MHz) 30-42 27-39 25-37 25.3-28.7 Receiver IF bandwidth (MHz) 10 20 30 28 Receiver noise figure (dB) 3 3 3 2 Receiver therma

44、l noise (dBW) 131 128 126 128 A 49 dBi antenna gain can be achieved with a diameter of approximately 4.8 m, whereas around 3.0 m is required to achieve 45 dBi. It is recognized that 4.8 m antennas are rarely used but that many FS systems operate with antenna sizes of typically 1.2 m and 2.4 m with c

45、orresponding gains of 37 and 40 dBi. In addition to radio-relay systems, some countries may also operate electronic news gathering (ENG) systems in the 7 750-7 900 MHz band. Antennas of such systems are typically smaller than those of radio-relay systems, which increase the visibility duration. On t

46、he other hand, acceptable interference levels are higher, providing a countering effect. Overall, the sharing situation is not expected to be significantly different to that for radio-relay systems. 5 Interference assessment to fixed service receivers In order to protect the FS systems, the followin

47、g power flux-density limits at the earths surface have been included in Article 21.16 of the RR for the band 7 750-7 850 MHz: 152 dB(W/m2/4 kHz) for angles of arrival () between 0 and 5above the horizontal plane; 152 dB + 0.5 (-5) (W/m2/4 kHz) for angles of arrival between 5 and 25; 142 dB(W/m2/4 kH

48、z) for angles of arrival between 25 and 90. This section will investigate whether these limits provide also sufficient protection for the planned extension. The assessment is based on Table 3 containing the extracted relevant information from Recommendation ITU-R F.758. The simulation method of Reco

49、mmendation ITU-R F.1108 is applied to determine the Fractional Degradation in Performance (FDP) of FS systems. Recommendation ITU-R F.1094 recommends a maximum allowable performance degradation of 10% for the FS. Based on a typical receiver noise density of 165 dB(W/4 kHz) this results in a maximum permissible FDP level of 181 dB(W/kHz). Figure 2 illustrates the geometrical constellation: Rep. ITU-R SA.2164 7 FIGURE 2 Potential interference constellation for fixed and meteorological satellite services Report 2164-02InterferenceMeteorologic