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Calculation of total emissions (including unwanted emissions) of IT falling in VR bandwidth

The emissions of Interfering transmitter (IT) are defined by means of emissions mask function dialog of _Δf, which establishes relative emission power levels as referred to carrier power (dBc), measured in reference bandwidth b_s specified by the user. The interfering transmitter power P_it (dBm) at f_it has therefore to be added for evaluating the link budget with the wanted receiver (i.e. power control).

The user should especially note that there is no separate parameter for the IT emissions bandwidth (e.g. channel bandwidth) and therefore the value of the emission bandwidth should be inherently contained in the shape of the IT emissions mask itself.

Note: See the discussion on the reference bandwidth settings in the emissions mask function dialog.

IT emissions mask

P^dBc_rel denotes the normalised emissions mask values in dBc/MHz. The normalised mask P^dBc_rel is derived from the initial (non-normalised) emissions mask entered by the user in form of triplets (Δf, unw(Δf), ref bw(Δf)) by adding the constant

-10log(ref_bw(Δf)/1MHz)

to each value unw, so that:

• P^dBc_rel = unw + 10 log (1/ref bw(MHz)) = unw + 10 log (1000/ref bw(KHz)).

The total interfering power of IT falling in the VR bandwidth, relative to IT carrier spur_rel , can be then calculated by integration of the IT emissions mask over the VR bandwidth between and , as follows:

The IT emissions mask is expressed as an array of N+1 points (Δfi, Pi) and assumed linear between these points:

This leads to:

where:

Eventually:

The total absolute power of IT emissions falling into VR bandwidth can be then derived by adding the previous result of relative emissions to the nominal output power P_it of the IT:

Unwanted emission floor

The aforementioned formulas are also applicable to derive the unwanted emissions floor value unwanted_floor(dBm) from the unwanted emissions floor function that might be defined in the scenario (often just the constant value is defined by the users), except that in the end no power is added since the unwanted emissions floor function is expressed in absolute dBm values.

If the unwanted emission floor option is selected in the scenario settings, then the programme will compare the value of total/unwanted emissions derived from the IT emissions mask as described in previous section with the value derived using unwanted emissions floor function and the larger value will be passed on into further calculations of iRSS_unwanted.

Note: The comparison involves the power control gain when the IT power control option is selected. The equation reads then:

P_it(dBm) + unwanted_rel(dBc) + G_PC > unwanted_floor (dBm)'