In the above list, you need to specify the '''No. Levels (M)''' for the Mary modulation schemes, from which the '''No. Bits per Symbol''' is determined. You can also define a bandwidth for the signal, which has a default value of 100MHz. Once the SNR of the signal is found, given the specified modulation scheme, the E<sub>b</sub>/N<sub>0</sub> parameter is determined, from which the bit error rate (BER) is calculated.
The quantity E<sub>b</sub>/N<sub>0</sub> is the ratio of energy per bit to noise power spectral density. It is a measure of SNR per bit and is calculated from the following equation:
<math> \frac{E_b}{N_0} = \frac{ 2^\eta - 1}{\eta} </math>
where η is the spectral efficiency.
The '''Minimum Required SNR''' parameter is used to determine link connectivity between each transmitter and receiver pair. If you check the box labeled '''Generate Connectivity Map''' in the receiver set property dialog, a binary map of the propagation scene is generated by EM.Terrano, in which one color represents a closed link and another represent no connection depending on the selected color map type of the graph. EM.Terrano also calculates the '''Max Permissible BER''' corresponding to the specified minimum required SNR and displays it in the receiver set property dialog.