1、STDOCEFT CEPT/ERC/REC L4-O2 E-ENGL 2776 H 23264I4 001453b 392 CEPT/ERC/REC 1442 E page 1 Distribution: B CEPT/J%RC/RECOMMENDATON 14-02 E (Bonn 1995) RADIO-FREQUENCY CHANNEL ARRANGEMENTS FOR MEDIUM AND HIGH CAPACITY ANALOGUE OR HIGH CAPACITY DIGITAL RADIOeRELAY SYSTEMS OPERATING IN THE BAND 6425 MHz
2、- 7125 MHz Recommendation proposed by the Workhg Group “Spectnun Engineering“ (WGSE) Text of the Recommendation adopted by the “European Radiocommunications Committee “ (ERC): “The European Conference of Postal and Telecommunications Administrations, considering 1) that radio-relay systems with a ca
3、pacity of 2700 telephone channels should prove to be. feasible in the 6 GHz band, if due care is exercised in the planning of radio paths to reduce mdtipath effects, 2) that it is sometimes desirable to be able to interconnect, at radio frequencies, radio-relay systems on international circuits in t
4、he 6 GHz band. 3) that it may be desirable to interconnect up to eight go and eight rem channels in a frequency band 680 MHz wide, 4) that economy may be achieved if at least four go and four return channels can be interconnected between radio-relay systems, each of which uses common transmit-receiv
5、e antennas, 5) that a common radio-frequency channel arrangement for both up to 1260 and 2700 telephone channel radio-relay systems offers considerable advantages, 6) that the use of certain types of digital modulation (see Recommendation ITU-R P.1101) permits the use of the radio-frequency channel
6、arrangement defined for 2700 telephone channel systems for the transmission of digital channels with a bit rate of the order of 140 MbitJs or synchronous digital hierarchy bit rates, 7) that for these digital 140 MbitJs radio systems, further economies are possible by accommodating up to eight go an
7、d return channels on a single antenna with suitable performance characteristics, 8) that many interfering effects can be reduced substantially by a carefully planned arrangement of the radio frequencies in radio-relay systems employing several radio-fiequency channels, 9) that the radio-frequency ch
8、annels should be so arranged that an intermediate fiequency of 70 MHz may be used for up to 1260 channel systems, 10) that the radio-fiequency channels should be so arranged that an intermediate frequency of 140 MHz may be employed for 2700 channel systems, 11) that single- and multi-carrier digital
9、 radio-relay systems are both useful concepts to achieve the best technical and economic trade-off in system design, 12) there are technical and economical advantages in adopting hannonised channel plans, Edition of August 26,1996 STD-CEPT CEPT/ERC/REC 14-02 E-ENGL 177b m 2326414 0014537 228 CEPT/ER
10、C/REC 14-02 E Page 2 noting a) that this recommendation is based on the IW-R Recommendation F.384, recommends that the preferred radio-frequency channel arrangement for up to eight go and eight return channels, each accommodating 2700 telephone channels, or a bit rate of the order of 140 Mbis, or sy
11、nchronous digital hierarchy bit rates (Note i), and operating at frequencies in the upper 6 GHz band, should be as shown in Annex I (Note 2), that, in the section over which the international connection is arranged, all the go channels should be in one half on the band, and all the return channels s
12、hould be in the other half of the band, that different polarisations should be used alternately for adjacent radio-frequency channels in the same half of the band, that, when common transmit-receive antennas are used, and not more than four channels are accommodated on a single antenna, it is prefer
13、red that the channel frequencies be selected by making either: n = 1,3,5 and 7 inbothhalves of theband or n = 2,4,6 and 8 in both halves of the band (Annex I, Section 3), that the preferred arrangement of radio-frequency polarisation should be one of those shown in Figure 1 (Annex 11, that a Co-chan
14、nel arrangement may also be used for digital radio-relay systems which can be derived from the arrangements given in Figure 1 (Annex I), that the preferred radio-frequency channel arrangement for up to 16 go and 16 return channels, each accommodating up to 1260 telephone channels, or the equivalent,
15、 or digital plesiochronous or synchronous medium capacity Tates, should be obtained by interleaving as shown at Annex II (Note 3), that, in the section over which international connection is arranged, all the go channels should be in one half of the band. hat different polarisations should be used a
16、lternately for adjacent radio-frequency channels in the same half of the band, Note 1: Actual gross bit rates including overhead may be as much as 5% or more higher than net transmission rates. Note 2: This radiefrequency channel arrangement permits ai local oscillator frequencies to be derived from
17、 a common oscillator, if &sired. Note 3: The radio-frequency channel arrangements for systems of up to 1260 channel capacity and of 2700 channel capacity may be used on intersecting routes, as long as adequate antenna discrimination is provided. Edition of August 26, i996 STD-CEPT CEPT/ERC/REC 14-02
18、 E-ENGL 3776 W 232bYI14 0034538 1b4 CEPTIERCIREC 14-02 E Page 3 10) that when common transmit-receive antenna are used, and not more than four radio-frequency channels are accommodated on a single antenna, it is preferred that the channel frequencies by selected by making either: N= 1, 5, 9, 13 or N
19、 = 2, 6, 10, 14 or N = 3,7, 11, 15 or N = 4, 8, 12, 16, in both halves of the ,mds and the preferred arrangement of radio-frequency polarisation is as shown in Figure 1 (Annex I). 11) that if muiti-carrier transmission (Note 4) is employed, the overall number of n carriers wiii be regarded as a sing
20、le channel. The centre hequency of that channel should be derived from recommends 1 or recommends 7, disregarding the actual centre frequencies of the individual carriers, which may vary, for technical reasons, according to practical implementations. Operation of multi-carrier systems is addressed i
21、n greater detail in Annex Il, 12) that the preferred centre frequency cfo) is 6770 MHZ, other centre frequencies may be used by agreement between the administrations concerned.“ Note4: A multi-&er system is a system with n (where rl) digitally modulated carrier signals simultaneously transmitted (or
22、 received) by the same radiefrequency equipment. The centre frequency should be regarded as the arithmetic average of the n individual carrier frequencies of the muiti-canier system. Edition of August 26,1996 STD-CEPT CEPT/ERC/REC 14-02 E-ENGL 1996 = 232641Y 0034539 OTO CEFT/ERC/REC 14-02 E Annex i,
23、 Page 1 xs MHZ 40 20 Annex I n fl h fl fn Z1S Z2S YS DS 1.8 6460 6740 6800 7080 35 45 60 340 1.16 6440 6740 6780 7080 15 45 40 340 MHZ MHz MHZ MHZ MHZMHzMHzhmz 1. DERIVATION OF RADIO FREQUENCY CHANNELS The radio frequency channel arrangement for carrier spacings of 40 MHZ and 20 MHz shall be derived
24、 as follows: Let fo be the fiequency (MHz) of the centre of the band of frequencies occupied, fn be the centre frequency (Mi-iz) of one radio-frequency channel in the lower half of the band, fn be the centre frequency (Mi-iz) of one radio-frequency channel in the upper half of the band, then the fre
25、quencies (MHz) of individual channels are expressed by the following relationships: a) for systems with a carrier spacing of 40 IWk lower half of the band: upper half of the band: fn = fo - 350 +40n fni=fo-10+40n where n = 1, 2, 3,4, 5, 6, 7 or 8 b) for systems with a carrier spacing of 20 MHz: lowe
26、r half of the band: upper half of the band h = fo - 350 + 20n fn = fo - 10 + 20 n wheren= 1, 2, 3, . 16 2. CALCULATED PARAMETERS ACCORDING TO ITU-R REC. 746 Z1S: lower guard band Z2S: upper guard band Edition of August 26,1996 STD-CEPT CEPTIERCIREC 34-02 E-ENGL 1996 232b4L4 0014540 812 9 CEFTERCIREC
27、 14-02 E Annex I, Pqe 2 3. OCCUPIED SPECTRUM: 6425 - 7125 MHz Figure 1 5 * 20 * 35 * 6425 MHz 7125 MHz a) Channel arrangement for antennas with double polarisation b) Channel arrangement for antennas with Sirigle polarisation - all fiequencies are in m, - the use of a single antenna working allows f
28、or seven go and retarn channels of 40 MHz with the channel arrangement of Fig. 1 (b). The channel arrangement of Fig. 1 (a) and suitable antenna performance gives higher isolation between transmit and receive channels, allowing the use of the eight go and return channels of 40 MHz. Edition of August
29、 26,1996 STD-CEPT CEPT/ERC/REC /Y-O2 E-ENGL 1996 = 2326434 001454L 759 CEPTERCIREC 14-02 E Annex II, Page 1 Annex II DESCRIITION OF A MULTI-CARRIER SYSTEM A multi-carrier system is a system with n (where nl) digitally modulated carrier signals shultaneously transmitted (or received) by the same radi
30、o-frequency equipment. For high capacity multi-carrier transmission, the centre frequency of the channel should coincide with one of the corresponding frequencies of the basic channel arrangements given in recommends 1 or recommends 7. The channel spacing may be an integer multiple of the basic valu
31、es defined by recommends 1 or recommends 7. Compatibility with existing configurations has to be taken into account when choosing the appropriate alternative. Examples of Co-polar channel arrangements using a two-carrier system with 64 QAM are shown below. Each carrier is modulated with 155.52 Mbit/
32、s (STM-1 radio relay system). In a mixed anaioguddigital environment the arrangement shown in Fig. 2 (a) is preferred because it places the carrier frequencies of the existing analogue system in the middle of the digital carrier pairs. The centre frequencies of this channel arrangement are derived f
33、rom recommends 1 by setting n = 2.4, 6, 8. Channel spacing is 80 MHz. Each RF-channel contains 2 x 2 carriers allocated at +17.5 MHz around the centre frequency using both polarisations. Fig. 2 (b) shows an interleaved channel arrangement where centre frequencies are derived from recommends 7 by set
34、ting N = 3,7,11,15. This channel arrangement is adequate in a purely digital environment and is preferred because it provides more symmetrical guardbands at the band edges. Edition of August 26,1996 STD.CEPT CEPT/ERC/REC 14-02 E-ENGL 1996 m 2326414 00145Q2 by5 m CEPTERCIREC 1402 E Annex II, Page 2 6
35、500 6580 6660 6740 I I I Figure2 6840 6920 7000 7080 I I I Example of radio-frequency channel arrangements for a 2 x 2 x 155.52 Mbis (STM-1 radio-relay system) operating with 80 MHz channel spacing in the upper 6 GHz band 6480 6560 6640 6720 I I I 6820 6900 6980 7060 I I I I I I (a) Channel arrangem
36、ent preferred if compatibility with analogae radio-relay systems is required. I I I I (b) Channel arrangement preferred if compatibility with analogue radio-relay systems is not required. - all frequencies are in MHz. Edition of August 26,1996 2326434 OOL4LOO 502 LVA Under study NOR Yes POR Yes I CE
37、PTERCREC 14-02 Radio-frequency channel arrangements for medium and high capacity analogue or high capacity digital radio-relay systems operating in the band 6425 MHz - 7125 MHz FVN I Yes I 2.9.1997. Regulation on radio licenses, arf 14 (Off.Gaz. of SVN, No. -7) AUT DNK FIN HNG HOL Yes Yes Yes Yes Planned Under Intent of this Recommendation is met through the national footnote H11 O of NTFA
