Most standards or specifications define for the measurement procedure of the blocking parameter a frequency offset between VL and IL large enough to not mix blocking with adjacent channel. For this, the standards define the interferer as single continuous wave signal representing the total power of the interfering transmitter. This procedure supposes a constant blocking attenuation of the receiver over the complete bandwidth of the interfering transmitter.

The currently in SEAMCAT implemented algorithm for the calculation of the impact due to blocking reflects exactly this measurement procedure, implicitly supposing the required offset, of course.

In case the bandwidth of the ILT covers areas of the blocking mask where the attenuation is not constant, it might lead to some inaccuracy if taking only one value of the mask at the centre frequency of the ILT, ignoring the shape of the mask.

In order to minimize this inaccuracy one has to take account of the shape of the blocking mask accordingly.

The attached contribution proposes an algorithm for the calculation of the resulting blocking response taking account of the bandwidth of the ILT as well as the shape of the blocking mask.

Any comment on this proposal is welcome.

Regards,
Karl