3
rd
Generation Rack-
Mount RDMS™
31
Quasonix, Inc.
Figure 31: Example Keypad Combination for Setting Bit Rate
If an out-of-range bit rate is entered, the maximum or minimum possible rate will be set by default. For instance, if
the user attempts to set the bit rate to 50 Mbps in SOQPSK-TG mode, the receiver will default back to 46 Mbps, the
highest possible rate in that particular mode.
4.4.2.5
Power Ratio (UQPSK Mode Only)
To properly distinguish the in-phase (I) component from the quadrature-phase (Q) component in a modulated
UQPSK signal, the demodulator requires knowledge of the ratio of power between the two components. This degree
of unbalance is specified in dB.
For example, if the I component has four (4) times the power of the Q component, the power ratio will be
10*log10(4/1) = 6 dB. If the I component has lower power than the Q component, this setting will be negative. For
example, if the I component has 1/5 the power of the Q component, the power ratio will be 10*log10(1/5) = -7 dB.
Note that small power ratios, between -3 dB and +3 dB, may be difficult for the demodulator to reliably distinguish.
Figure 32: Main Menu, Power Ratio Setting
Figure 33: Power Ratio Entry Screen
4.4.2.6
Combiner (Optional)
A pre-detection diversity combiner is available as an option for dual-channel receivers. If diversity combining is
installed on the RDMS™, it can be enabled through the Main Menu > Comb
iner option.
