1、STD-CEPT ERC REPORT 54-ENGL 1777 2326434 OOL3400 368 m ERC REPORT 54 European Radiocommunications Committee (ERC) - within the European Conference of Postal and Telecommunications Administrations (CEPT) i-.- INTERFERENCE FROM UNWANTED EMISSIONS OF MOBILE EARTH STATIONS GSO MSS SATELLITES OPERATING A
2、BOVE 1626.5 MHz IN S-PCN SYSTEMS OPERATING IN THE BAND 1610 - 1626.5 MHz INTO Sesimbra, January 1997 STD.CEPT ERC REPORT 54-ENGL II777 m 2326424 OOII34OL 2T4 m Copyright 1998 the European Conference of Postal and Telecommunications Administrations (CEPT) STD-CEPT ERC REPORT 54-ENGL 1997 D 2326414 00
3、13402 130 m ERC REPORT 54 Page 1 INTERFERENCE FROM UNWANTED EMISSIONS OF MOBILE EARTH STATIONS GSO MSS SATELLITES OPERATING ABOVE 1626.5 MHz IN S-PCN SYSTEMS OPERATING IN THE BAND 1610 - 1626.5 MHz INTO 1 INTRODUCTION This report studies the potential interference into geostationary (GSO) Mobile-Sat
4、ellite Service (MSS) satellites from unwanted emissions of Satellite Personal Communication Networks (S-PCN) Mobile Earth Stations (MES) operating in the band 1610 - 1626.5 MHz, where the MES conform to the unwanted emission limits given in ETS 300 733. The GSO MSS satellites studied were Inmarsat-2
5、 and Inmarsat-3, Interference was calculated both from the point of view of total noise increase and in terms of return link loading and C- band (4 GHz) feederlink power robbing. It should be noted that this study does not consider the impact of unwanted emissions from S-PCN satellites. 2 MES UNWANT
6、ED EMISSIONS Tables 2 and 3 of ETS 300 733 give limits for the unwanted emissions of MES operating in S-PCN systems in the band 1610 - 1626.5 MHz. An S-PCN system was assumed to be operating in the band 1621.5-1626.5 MHz. The system was assumed to have 120 equally spaced RF channels in the 5 MHz sys
7、tem bandwidth, i.e. the channel spacing is 41.67 kHz. The nominated bandwidth was assumed to be the maximum permitted by the definition, as shown in Table 1. The interfering EIRP in a 5 kHz and a i5 kHz channel just above the band edge 1626.5 MHz was calculated based on the unwanted emission mask of
8、 ETS 300 733. The results are given in Table 1. The interfering EIRP of the MESS was reduced by 4 dB to take account of voice activation and by 2 dB to take account of power control. 3 INTERFERENCE ANALYSIS 3.1 CA analysis To compute the aggregate interference from a population of MES spread across
9、the Earths surface, the field of view of the GSO MSS satellites was divided into a number of concentric rings. The interference power (I) into the Inmarsat-2 global beam and into the Inmarsat-3 (assumed sub-satellite) spot beam was then calculated from the following equation: (EfR?+IO log(ni)-Li+Gi)
10、 i=l where EIRP is the unwanted EIRP from each MES in dBW in the relevant bandwidth; 0 ni is the number of MES in ring i; 0 Li is the free space propagation loss from the inner edge of ring i in dB; 0 Gi is the satellite receiving antenna gain at the corresponding off-axis angle in dBi. The average
11、MES interfering EIRP as given in Table 1 was used. This corresponds to a uniform distribution of MES, both geographically and in frequency. The resulting C/I, values for an Inmarsat-3 spot beam and for an Inmarsat-2 global beam are given in Tables 2 and 3 respectively. * The version approved for pub
12、lic vote at the Edinburgh SES meeting, Nov. 1996. STDmCEPT ERC REPORT 54-ENGL 1997 2326414 0033403 077 W ERC REPORT 54 Page 2 Channel no. 3.2 Power robbing analysis Nominated bandwidth Interfering EIRP in a 5 kHz Interfering EIRP in a 15 kHz channel channel Next, the equivalent C-band EIRP was calcu
13、lated: EIRP, = I - G, - G, where 0 GEX is the satellite receiving antenna gain at edge of coverage; G, is the satellite transponder gain. 1 I 41.67 kHz I -42.78dBW 2 I 125 kHz I -42.78 dBW I The “power robbing” was then calculated, Le. the percentage of the available C-band EIRP that would be used u
14、p by the interference. The power robbing is about 0.01% in all cases, assuming a total available C-band EIRP of 30 dBW in 17 MHz (assumed feederlink bandwidth used). -38.01 dBW -38.01 dBW 4 CONCLUSIONS 7 10 15 The calculations have shown that the likely interference impact of TDMA S-PCN terminals op
15、erating below 1626.5 MHz on GSO MSS satellites in the adjacent band above 1626.5 MHz will be acceptable with the unwanted emission limits of ETS 300 733. Thus, ETS 300 733 should provide sufficient protection for GSO MSS systems operating in the band 1626.5 - 1660.5 MHz, at least in the case where a
16、 TDMA S-PCN system is operating adjacent to the GSO MSS system. 166.67 kHz -44.40 dBW -39.89 dBW 166.67 kHz -47.66 dBW -42.96 dBW 166.67 kHz -50.84 dBW -46.15 dBW 36 46-120 166.67 kHz -61.01 dBW -56.27 dBW 166.67 kHz -63.78 dBW -59.01 dBW I I I I 3-6 I 166.67 kHz I -42.78dBW I -38.01 dBW Average of
17、all channels Average of all channels except 1 Average of all channels except 1,2 Average of all channels except 1,2,3 -52.91 dBW -48.18 dBW -53.26 dBW -48.53 dBW -53.65 dBW -48.93 dBW -54.09 dBW -49.37 dBW I I I 1 19-35 I 166.67kHz I -52.78dBW I -48.01 dBW I I I I I I iNMC DATA 4.6 0.75 23 189.11 3.
18、2 -164.71 62.07 32.3 54.5 7.57 Table 2: C/I, calculation for Inmarsat-3 spot beam STD-CEPT ERC REPORT 54-ENGL L997 m 2326434 0033404 703 m CARRIER INM-B VOICE INM-M(M) VOICE INM-M(L) VOICE ERC REPORT 54 Page 3 Cno THRESHOLD THRESHOLD MARGIN MIN OCCUPIED RECEIVER PROP RANDOM C EIRP BANDWITH ANTENNA MSS LOSS CMo+lo CAO (dBW OCHZ) GAiN(dBi) (dB) (dB) (dBW) (dB) (dBHz) (dB) (dB) 30.7 15 16 189.11 5 -147.41 79.71 46.9 69.1 10.61 25.8 5 16 189.11 5 -152.31 74.51 42 64.2 10.31 25.8 5 16 189.11 5 -152.31 74.51 42 64.2 10.31
