1、STD-CEPT ERC REPORT 71-ENGL L997 W 232b414 OOLb278 982 ERC REPORT 71 European Radiocommunications Committee (ERC) within the European Conference of Postal and Telecommunications Administrations (CEPT) SHARING STUDIES BETWEEN THE UNWANTED EMISSIONS OF MSS MOBILE EARTH STATIONS, OPERATING IN THE BAND
2、1610 - 1626.5 MHz AND RADIO NAVIGATION - SATELLITE SERVICE RECEIVERS OPERATING IN THE BAND 1559 - 1610 MHz Luxembourg, September 1999 Copyright 1999 the European Conference of Postal and Telecommunications Administrations (CEFT) - . STD-CEPT ERC REPORT 72-ENGL 1999 W 232bllItll 002b2BO 530 W ERC REP
3、ORT 71 INDEX TABLE 1 INTRODUCTION 1 2 SYSTEMS PRESENTATION . 2 2.1 MSS SYSTEM 2 2 . 1 . 1 Introduction 2 2.1.2 Globalstar description 2 2.2 RNss SYSTEMS . 3 2.2.1 GLONASS . . . 3 2.2.2 GPS . 4 2.2.3 GNSS 5 SHARING STUDIES SCENARIOS . 5 3.1 INTRODUCTION . . 5 3.2 EN-ROUTE SCENARIO . . 6 3.2.1 Descrip
4、tion . 6 3.2.2 Link budget . 6 3.2.3 Conclusion 7 LANDING AND LANDING APPROACH SCENARIO 8 3.3.1 Description . 8 3.3.2 Link budget . 8 4 CONCLUSION . 11 Annex 1: Extract of TBR041 . 12 Annex 2: Extract of Rec . M.1317 ITU-R 13 Annex 3: Extract of Rec . M.1088 ITU-R 14 Annex 4: Estimation of the impac
5、t of Globalstar MES into GLONASS PAS and SAS receivers on board of an aircraft for the 15 3 3.3 worst case scenario described in the main body of this report STD*CEPT ERC REPORT 71-ENGL 1779 = 232b1i14 001b28L Li77 9 ERC REPORT 71 Page I SHARING STUDIES BETWEEN THE UNWANTED EMISSIONS OF MSS MOBILE E
6、ARTH STATIONS, OPERATING IN THE BAND 1610 - 1626.5 MHz AND RADIO NAVIGATION - SATELLITE SERVICE RECEIVERS OPERATING IN THE BAND 1559 - 1610 MHz 1 INTRODUCTION The purpose of this report is to synthesise the different studies, which were conducted in SE28 on sharing between the unwanted emissions of
7、mobile earth stations of the Mobile-Satellite Service (MSS), operating in 1610 - 1626.5 MHz, in the Earth-to-space direction with a primary status and the Radio Navigation-Satellite Service receivers (RNSS) operating in the band 1559 - 1610 MHz, in the space-to-Earth direction with a primary status.
8、 The Mobile Earth Stations (MES) considered in this report are covered by TBR041. Thus, this excludes aeronautical earth stations. The unwanted emissions of the MES spread into the operational band of RNSS, as shown in Figure 1. If the level of the unwanted emissions is too high, it will cause harmf
9、ul interference into the RNSS receiver. The purpose of these studies was to derive an acceptable value for the unwanted emissions of the MSS MES in the band 1559 - 1610 MHz. 1626.5 1559 1610 RADIONAVIGATION BY SATELLITE -(Space to Earth) Figure 1: Sharing situation in adjacent bands between MSS and
10、RNSS In the studies, particular attention has been paid to the fact that the RNSS systems will be used for safety purposes, when on board an aircraft. 2 SYSTEMS PRESENTATION 2.1 MSS system 2. I. 1 Introduction As we can see in the Figure 2, all the MSS systems operating in the band 1610 - 1626.5 MHz
11、 are implied in the sharing situation. However, to allow all the systems wishing to operate in this band to have an equitable access of the spectrum, taking into account the access techniques, a band segmentation has been decided by CEPT. To summarise the ERC decision, we may say that this band segm
12、entation allows CDMA systems to operate in the lower portion of the band (1610 - 1621.35 MHz) and the TDMA systems to operate in the upper part of the band (1621.35 - 1626.5 MHz). That is why in our simulations, we will use the characteristics of the Globalstar system, which uses the CDMA technique
13、and thus which will be directly adjacent to the RNSS band. 2.1.2 Globalstar description Globalstar system is a satellite-based, wireless telecommunications system designed to provide voice, data, fax, and other telecommunications services to users world-wide. Users of Globalstar will make or receive
14、 calls using hand-held or vehicle mounted terminals similar to todays cellular telephones. It should be noted that most of the terminals will be dual-mode, Le. GSM/Globalstar or IS95/Globalstar. Consequently, when user terminals are within the terrestrial network coverage, they will use the cellular
15、 network, when outside this coverage, they will communicate via satellite. Calls will be relayed through the Globalstar satellite constellation, in a 1414 kilometre altitude orbit, to a ground station, and then through local terrestrial systems to their final destinations. Fifty six Globalstar satel
16、lites will be placed into low earth orbit, 48 of which will be operational, with eight in-orbit spares. The satellites will be placed in eight orbital planes of six satellites each with a circular orbit inclined at 52 degrees. The satellite mass is approximately 450 kilograms, and requires some 1,10
17、0 watts of power for normal operations. The satellites in the first-generation constellation are designed to operate at full performance for a minimum of seven and one half years. Globalstar 0 0 113 minutes of period 0 70“N to 70“s coverage 0 48 LEO satellites + 8 spare in orbit Bent Pipe relay to l
18、ocal gateway 8 planes with 6 satellites each 1414 km altitude, 52“ inclination Multisatellite coverage in temperate zone Figure 2: Typical MSS system It is important to note that the Globalstar MES is covered by TBR041 (see Annex 1). STD=CEPT ERC REPORT 71-ENGL 1997 D 232blllq 001b283 24T W ERC REPO
19、RT 71 Page 3 2.2 RNSS systems 2.2.1 GLONASS The GLONASS Global Navigation Satellite System is designed for position-fixing as well as for velocity and precise time determination for maritime, aeronautical, land and other users. The system service zone provides global continuous and all- weather oper
20、ation. Three-dimensional user co-ordinates and velocity findings are based on measurements propagation time of the GLONASS satellites transmitted signals and of their frequency Doppler shift. GLONASS is one of the elements of the Global Navigation Satellite System (GNSS) and is used for providing sa
21、fety of aircraft flights. RR S4.10 states that safety services require special measures to ensure freedom from harmful interference. GLONASS operates within the Radionavigation-Satellite Service band (1592 - 1610 MHz) on a primary basis in all three Regions. According to the Russian Federation, GLON
22、ASS frequency assignments in the band up to 1610 MHz are completely co-ordinated according to the ITU procedures and based on RR. S4.10, S1.169, S4.5; they require protection from any harmful interference including those produced by unwanted emissions from systems operating in the adjacent frequency
23、 band 1610 - 1626.5 MHz. The GLONASS system consists of three main segments. They are: 0 Space segment Ground control segment User terminals (UT) The GLONASS space segment consists of 24 operating satellites (and some stand-by ones) that are evenly located in three orbital planes with eight satellit
24、es in each. The separation angle of the planes is 120“. The orbit inclination is 64.8“. Its altitude is 19100 km and an orbital period is 11 hours 15 minutes. The navigation service zone is established by transmitting navigation signals in the two RNSS bands, 1559 - 1610 MHz (called L1) and 1215 - 1
25、260 MHz (called L2) from each satellite. Navigation data is transmitted at a rate of 50 bps. They contain data on satellite location within three rectangular co-ordinates, on velocity vector component and acceleration in a geocentric Earth fixed frame of reference (the ECEF co-ordinate system), on c
26、orrections for the GLONASS system time and on-board equipment health information for every half-hour period. For users, the main elements of navigation signals are data for clock corrections and satellite three-dimensional position parameters (ephemerides). For position fixing and time determination
27、 users have to track constantly and successively signals from at least four satellites. The GLONASS system uses frequency division multiple access (FDMA) for navigation signals from satellites in both sub- bands (L1 and L2). Each satellite transmits radio signals on their own frequencies, sub-bands
28、of L1 and L2. In the downlink of the L1 frequency sub-band, the GLONASS satellites transmit navigation signals of two types, i.e. of a standard accuracy and of a precision one. The standard accuracy signal (SAS) has a chipping rate of 0.5 11 MHz. The SAS is available for any user who has an appropri
29、ate navigation receiver and if certain GLONASS satellites are in its field of view. The precision accuracy signal (PAS) with a chipping rate of 5.11 MHz is modulated with a specific code and is not intended for use without approval of the Russian Federation Ministry of Defence Military Space Force.
30、The GLONASS ground segment controls satellites, performs management functions and calculates navigation data (ephemerides). The segment consists of the Master Control Station and control and up-loading stations. Data of navigation measurements at each control station are processed at the Master Cont
31、rol Station and are used for computation of ephemerides to be transmitted to the satellites from the up-loading stations. To ensure proper operation of the entire system high precision satellite clock synchronisation is required. It is effected by transmitting clock correction data from the Master C
32、ontrol Station. The GLONASS-M (GLONASS modernised version post 2005) frequency plan has three stages of transition. Prior to 1998.25 MHz separate frequency carriers were used in the L1 and L2 bands: the L1 band used carrier frequencies 1602.00 MHz (lowest) to 1615.50 MHz (highest) and the L2 band us
33、ed carrier frequencies 1246.00 MHz (lowest) to 1256.50 MHz (highest). However, carrier frequencies in the 1610.6 - 1613.8 MHz band were not used. During the second stage, 1998 - 2005.21 MHz carrier frequencies will be used in the LI and L2 bands. The L1 band will use carrier frequencies 1598.0625 MH
34、z (lowest) to 1609.3125 MHz (highest) and the L2 band will use carrier frequencies 1242.9375 MHz (lowest) to 1251.6875 MHz (highest). The highest carrier frequencies, 1609.3125 MHz and 125 1.6875 MHz will be used only under exceptional circumstances. STD-CEPT ERC REPORT 72-ENGL 1777 232b414 002b284
35、LBb ERC REPORT 71 Page 4 After 2005, GLONASS-M will use 14 carrier frequencies. The highest two carriers of both L1 and L2 frequency bands will only be used as technical channels (for launch and test). Therefore, the GLONASS-M system in the LI band will use carrier frequencies 1598.0625 MHz (lowest)
36、 to 1605.3750 MHz (highest) and the L2 band will use carrier frequencies from 1242.9375 MHz (lowest) to 1248.6250 MHz (highest). However, carrier frequencies 1604.8125 MHz and 1605.375 MHz in the LI band and 1248.1875 MHz and 1248.6250 MHz in the L2 band will be used as technical channels when the s
37、atellite is over the Russian Federation. According to the Russian Federation, the total frequency band to be used by the GLONASS system, covering both SAS and PAS, is in the first stage: 1596.89 - 1620.61 MHz in the band L1 and 1240.89 - 1261.61 MHz in the band L2; in the second stage 1592.9525 - 16
38、13.86 MHz and 1237.8275 - 1256.36 MHz; in the third stage 1592.9525 - 1609.36 MHz and 1237.8275 - 1252.86 MHz. The RF part of the receiver is typically comprised of a bandpass filter, a preamplifier and a multistage down-converter. The bandpass filter is to provide rejection of out-of-band signals.
39、The preamplifier has a diode limiter to protect the receiver from damage when a high-powered interference signal is present. The digital part of the receiver and the processor provides the signal equalisation, PN code tracking, carrier phase tracking, digital data demodulating and time marking. The
40、receiver input bandwidth is +20 MHz (-3 dB level) and tr45 MHz (-30 dB level); the noise temperature is 300 K (typical). The characteristics of the system to be used in sharing studies are described in ITU-R Recommendation: M.1317 (See Annex2). 2.2.2 GPS Introduction The Global Positioning System (G
41、PS) consists of 24 satellites with four satellites in each of the six 55“ inclined, equally spaced, orbital planes. Each satellite transmits the same two frequencies for navigational signals. These navigational signals are modulated with a predetermined pseudo-random bit stream, modulated with navig
42、ation data containing ephemeris data, clock correction, etc. and having a sufficient bandwidth to produce the necessary navigation ranging precision without recourse to two-way transmission or Doppler integration. The system will provide accurate position determination in three dimensions anywhere o
43、n or near the surface of the Earth. Frequency requirements The frequency requirements for the GPS system are based upon an assessment of user accuracy requirements, space-to- Earth propagation delay resolution, multipath suppression, and equipment cost and configurations. Two channels were selected
44、for GPS operations: 1575.42 MHz (Ll) and 1227.6 MHz (L2). The L1 channel is used to enable quick acquisition and in addition can resolve a users location to better than 150 m. A second signal transmitted on both LI and L2 channels, provides the necessary frequency diversity necessary for ionospheric
45、 delay correction and wider bandwidth for increased ranging accuracy and for multipath suppression to increase the total accuracy by over an order of magnitude. Telemetry and maintenance signals from United States based control facilities to the satellite and return are accommodated in the allocated
46、 telemetry band in the United States of America. GPS will provide a worldwide navigation service. The requirement for navigation safety (refer to Radio Regulation No. S4.10) demanded by such a service underscores the critical importance that other radio services should not cause harmful interference
47、 to GPS receivers. Space Segment The Space Segment comprises the GPS satellites, which function as “celestial“ reference points, emitting precisely time- encoded navigation signals from space. The operational constellation of 24 satellites operates in 12 h circular orbits with a semi-major axis of a
48、bout 26 600 km. The satellites will be placed in six orbital planes inclined 55“ relative to the Equator. The satellites are optimally phased to provide visibility to the users of at least five satellites at elevations greater than 5“ above the horizon. I ERC REPORT 71 Page 5 User Segment The User S
49、egment is the collection of all user sets and their support equipment. The user set typically consists of an antenna, GPS receiver/processor, computer and input/output devices. It acquires and tracks the navigation signal from four or more satellites in view, measures their RF transit times and Doppler frequency shifts, converts them to pseudo-ranges and pseudo-range rates, and solves for three-dimensional position, velocity, and system time. User equipment ranges from relatively simple, lightweight hand-held receivers to sophisticated receivers that are integrated with other naviga
