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1497, Annex 1 1497, Annex 2

56; 28; 14; 7; 3.5 100; 50

frequency block bandwidth.

bBasic frequency slot for aggregating wider frequency block bandwidth.

frequency block bandwidth.

bBasic frequency slot for aggregating wider frequency block bandwidth.

Note:1 A given frequency channel arrangement can be regarded as either alternated or interleaved as a consequence of the symbol rate transmitted by the radio systems. Alternated frequency channel arrangements may be, in principle, further implemented with co-channel band reuse. Note 2: The definition and application of XPD is different from that of cross-polarization isolation (XPI) as defined in Recommendation ITU-R P.310. Note 3: In the definition of NFD the following assumptions are made:

• Adjacent channels XPD, if any, has not been taken into account.

• A single side interfering channel only is considered; for double side like-modulated interferences a NFD value 3 dB lower should be taken into account.

Note 4: This argument is covered by the outage and propagation behavior prediction methods covered by Recs. ITU-R F.1093 and ITU-R P.530.

Note 5: A multicarrier system is a system with n (where n > 1) digitally modulated carrier signals simultaneously transmitted (or received) by the same radio-frequency equipment. The center frequency should be regarded as the arithmetic average of the n individual carrier frequencies of the multicarrier system. When applying a multicarrier system in an already existing radio-frequency channel arrangement, it may be convenient to shift the center frequency of the multicarrier system to the middle of two adjacent channels of the basic arrangement. Source: Tables 1 and 2, pp. 5-8, ITU-R Rec. F.746-8, 2006 F Series (Ref. 26).

Frequency range

L.ower band

□ . m m „ n >

,°n . n m „ ,

1 A t 1 " \ Center 1 // 1-T. |*9aPr|

Figure 2.32. A generalized ITU frequency arrangement.

Figure 2.32. A generalized ITU frequency arrangement.

Figure 2.33. Channel arrangements for three possible schemes considered in ITU radio-frequency channel arrangement. (From Figure 1, ITU-R F.746-8, 2006 F Series Ref. 26.)

Where two or more RF channels are to be provided over a route, frequencies should first be assigned from the odd-numbered group of channels or from the even-numbered group of channels, but not from both, since this would require the use of two antennas at each end of each section. As an example, when all the channels from the odd-numbered group have been assigned, further expansion from the even-numbered group would be provided by means of a second antenna with polarization orthogonal to that of the first antenna.

The main parameters affecting the choice of radio-frequency channel arrangements are as follows (see Figure 2.33):

XS Defined as the radio-frequency separation between the center frequencies of adjacent radio-frequency channels on the same polarization and in the same direction of transmission.

YS Defined as the radio-frequency separation between the center frequencies of the go and return radio-frequency channels that are nearest to each other. In the case where go and return frequency subbands are not contiguous, such that there is a (are) band(s) allocated for (an)other service(s) in the gap between, YS shall be considered to include the band separation (BS) equal to the total width of the allocated band(s) used by this (these) service(s).

ZS Defined as the radio-frequency separation between the center frequencies of the outermost radio-frequency channels and the edge of the frequency band. In the case where the lower and upper separations differ in value, Z1S refers to the lower separation and Z2S refers to the upper separation. In the case where go and return frequency subbands are not contiguous, such that there is a (are) band(s) allocated for (an)other service(s) in the gap between, ZSi will be defined for the innermost edges of both subbands and will be included in YS.

DS Tx/Rx duplex spacing, defined as the radio-frequency separation between corresponding go and return channels, constant for each couple of ith and i'th frequencies, within a given channel arrangement.

The choice of radio-frequency channel arrangement depends on the values of cross-polar discrimination (XPD) and on the net filter discrimination (NFD) where these parameters are defined as follows:

power received on polarization H(V)

transmitted on polarization H(V )

v ; power received on opposite polarization V( H )

transmitted on polarization H(V)

adjacent channel received power

adjacent channel power received by the main receiver after RF, IF, and BB filters

The XPD and NFD parameters (dB) contribute to the value of carrier-to-interference ratio.

If XPDmin is the minimum value reached for the percentage of time required, from this value and from the adjacent channel NFD, the total amount of interfering power can be evaluated, and this result must be compared with the minimum value of carrier-to-interference (C/I)min acceptable to the modulation adopted.

Alternated channel arrangements can be used (neglecting the co-polar adjacent channel interference contribution) if:

Co-channel arrangements can be used if:

XPD +XIF + NFDa - 3 10 10 10 10 Interleaved channel arrangements can be used if:

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