A8.2 SCHEMATIC DESCRIPTION OF THE IRSS_BLOCKING ALGORITHM
A8.2.1 Â Case 1: No overlap
Figure 386: Â iRSS_blocking case 1: no overlap
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where:
lower: offset - BWILT/2 – emission mask asymmetry[1]
upper: lower + BWILT
dF:Â step size, e.g. min{0.1;( BWILT)/20}
A8.2.2 Â Â Case 2: Partial overlap with fILT > fVLR
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Figure 387: iRSS_blocking case 2: partial overlap with fILT > fVLR
Note: the blue coloured range is covered by the iRSS_unwanted calculation and therefore not taken into account in the iRSS_blocking calculation.
where:
lower: BWVLR/2
upper: offset + BWILT/2 – emission mask asymmetry
dF: step size, e.g. min{0.1;( BWILT)/20}
A8.2.3Â Â Â Case 3: Partial overlap with fILT < fVLR
Figure 388: iRSS_blocking case 3: partial overlap with fILT < fVLR
Note: the blue coloured range is covered by the iRSS_unwanted calculation and therefore not taken into account in the iRSS_blocking calculation.
where:
upper: - BWVLR/2
lower: – offset - BWILT/2 – emission mask asymmetry
dF: step size, e.g. min{0.1;( BWILT)/20}
A8.2.4Â Â Case 4: Total overlap with BWVLR < BWILT
Figure 389: iRSS_blocking case 4: Total overlap with BWVLR < BWILT
Note: the blue coloured range is covered by the iRSS_unwanted calculation and therefore not taken into account in the iRSS_blocking calculation.
where:
lower: offset - BWILT/2 – emission mask asymmetry
upper: lower + BWILT
dF: step size, e.g. min{0.1;BWVLR/5} 1) excluding the range fVLR ± BWVLR/2
Note that at least 3 samples are required for the range fVLR ± BWVLR.
A8.2.5Â Â Case 5: total overlap with BWVLR > BWILT
Figure 390: iRSS_blocking case 5: total overlap with BWVLR > BWILT
In this case, there is no blocking as the interference is completely covered by the unwanted calculation. The blocking attenuation is therefore set to 1000 dB.
A8.2.6Â Â Implementation of the integral for iRSS_blocking
The integral requires positive values of the blocking mask, i.e. the blocking mode has to be considered first.
where: n = range/dFÂ Â and range = upper-lower
The parameter maskValue(f) corresponds to the following equations (see section ‎1.4.6).
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- For generic systems in user-defined mode, it corresponds to the mask specified in the receiver settings;
maskValue(f) = BlockUD (dB).
- For generic systems defined with blocking modes different to user-defined (i.e. sensitivity and protection ratio);
- Protection Ratio (dB):
maskValue(f) = BlockPR (dB) + C/(N+I) (dB) + (N+I)/N (dB) - I/N (dB)Â
- Sensitivity Mode (dBm):
maskValue(f)  = BlockSens (dBm) – SensitivityVLR (dBm) + C/(N+I) (dB) – I/N (dB)  Â
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- For cellular systems:
- If the mask is defined in positive values (ACS), then maskValue(f) corresponds to the mask specified in the receiver settings;Â Â Â Â Â
- If the mask is defined in negative values, then maskValue(f) corresponds to the calculated positive mask using the input parameters Standard Desensitisation  and I/N_target (see section ‎A8.2.8).
A8.2.7Â Â Considerations on the bandwidths used in the integral
Calculation of BW for GENERIC systems
The algorithm is based on the mask entries and takes the values as relative to the carrier (dBc) at the zero offset.
It consists of two loops, one for the upper part of the mask, the second for the lower part.
The loops stop if the relative power of the actual offset is less than the limit .
The lower and upper bound are saved as they are required by the calculation algorithm so that the blocking average takes account of symmetrical emission masks.
Calculation of BW for OFDMA
For a Base Station: the total number of resource blocks (max. RBs per BS) multiplied by the bandwidth of one resource block.
For a User Equipment: the bandwidth is: the number of RBs per MS (UE) multiplied by the bandwidth or one resource block.
Calculation of BW for CDMA
The algorithm uses the reference bandwidth of the system, which is the same for either BS or UE (user defined in CDMA general settings). .
A8.2.8Â Â Conversion of negative blocking mask values in cellular receivers (OFDMA and CDMA)
In case of receivers of cellular systems (OFDMA and CDMA), if the mask has negative values, it needs to be converted using the following input parameters in the receiver settings:
- Standard desensitisation (for which the blocking mask values where derived);
- Target I/NÂ (which depends on the scenario considered and can be extracted from the CEPT/ECC or ITU-R deliverables ).
If the mask is entered as positive values then these parameters are not used.
Figure 391: Input parameters for cellular receivers blocking masks
Default values of standard desensitisation and Target I/N are specified in the table below.
Table 68: Default values of standard desensitisation and Target I/N
 | Standard Desensitsation (dB) | Target I/N (dB) |
OFDMA UL | +6 | -6 |
OFDMA DL | +6 | -6 |
CDMA UL | +6 | -6 |
CDMA DL | +3 | -6 |
The algorithm to convert negative blocking mask values is as follows:
Blocking Response = IOOB_target – Noise floor – I/Ntarget
where:
- I/Ntarget is always understood as ‘target I/N of the victim’, which is calculated for D_target (target desensitisation)
- Noise floor = 10*log(kTB) + F.
- K= Boltzmann Constant
- T = Noise temperature (Kelvin)
- B = Receiver bandwidth in MHz
- F = Noise Figure (dB)
- IOOB_target is calculated as follows :
IOOB-TARGET = IOOB-STANDARD – DSTANDARD + DTARGET
where:
- IOOB-STANDARD = is the original blocking mask;
- DSTANDARD = is the standard desensitisation for which the blocking mask values (IOOB-STANDARD) were derived. It is an input of cellular receiver settings (see Figure 389).
- DTARGET = 10*log10(10^(I/N_target/10)+1) ; where I/N_target is an input of cellular receiver settings.
Finally, we obtain:
Blocking Response = IOOB-TARGET – Noise floor– I/Ntarget, which means:
 Blocking Response = IOOB-STANDARD – DSTANDARD + DTARGET – kTBF – I/Ntarget     Â