The level of interference due to receiver blocking , i.e. the power captured from the transmissions of the interferer due to selectivity imperfections of the victim’s receiver (Figure 12), is determined using the interferer’s transmit power, the victim link receiver’s blocking performance, the interferer/victim frequency separation, antenna gains and propagation loss. Details on the iRSSblocking calculation are given in ANNEX 5:.
Note that with SEAMCAT 5.0.1, the blocking attenuation is computed at the ILT frequency and that the ILT bandwidth is nowconsidered (see ANNEX 8:). There are 3 ways to calculate the blocking response which are described in more detail in ANNEX 8::
User Defined (dB): AttBlocking = BlockUD (dB) (Eq. 13)
Protection Ratio (dB): AttBlocking = BlockPR (dB) + C/(N+I) (dB) + (N+I)/N (dB) - I/N (dB) (Eq. 14)
Sensitivity Mode (dBm): AttBlocking = BlockSens (dBm) – SensitivityVLR (dBm) + C/(N+I) (dB) – I/N (dB) (Eq. 15)
Figure 12: Illustration of the blocking of the victim link receiver (i.e. total emission power of ILT reduced by the blocking attenuation (selectivity) function of the VLR