Diversity Options

The basic space diversity methods are set under Configure-Options-Calculation Options-Transmission calculations-Diversity methods.

Note that the options under SD improvement and Angle diversity method are provided for compatibility with radio equipment manufacturers in house software programs.

The maximum diversity improvement factor applies to all type of diversity (space, frequency and quad)

Select Operations-Diversity Parameters to access the Diversity Parameters dialog box. The settings in this dialog are extensions to the general options under Configure-Options-Calculation Options-Transmission calculations-Diversity methods which are applied to specific links

 

Frequency diversity

Frequency diversity will be enabled under the following conditions:

• the "Use TX channel assignments" option is checked and the transmit channel table contains more than one frequency entry. The effective frequency spacing will be calculated based on the number of channels.
• the "Use TX channel assignments" option is not checked and the and values have been entered for the frequency diversity spacing at site 1 and site 2

Diversity radio type

Select either base band switching or IF combining. The diversity radio type can be specified in the radio data file. Space diversity radios using IF combining can improve the thermal fade margin up to 3 dB. This improvement can also be specified in the radio data file. The default improvement is 2.6 dB. The actual improvement depends on the difference between the main and diversity receive signals signal and the combiner efficiency. It can be argued that this improvement is artificial and is not realized in practice. During deep fades, there will be significant difference between the main and diversity signals; and therefore, the performance will be identical to a baseband switching system.

Angle diversity

Angle diversity can be specified at either or both sites. A space diversity antenna configuration must be selected. Angle diversity cannot be used with a hybrid diversity antenna configuration. At the angle diversity site set both antenna heights to the same value. The display will show a 30 foot (9.1 meter) angle diversity separation between the antennas. The overall improvement for angle diversity is calculated using a 30 foot separation. The improvement will be the same for the dispersive component as in conventional space diversity; however, the improvement to the flat component will be one tenth of conventional space diversity.