Quasonix TIMTER Installation And Operation Manual page 30

TIMTER™ Multi-mode Dual
Telemetry Transmitter
In the Space-Time Coding (STC) mode of operation, the data stream is encoded into two separate signals that each
contain a complete copy of the source data. These two signals are transmitted simultaneously on the same RF
frequency (usually over two separate antennas) to produce a radiated over-the-air signal that eliminates antenna self-
interference and improves message detectability with a similar bandwidth requirement as a conventional SOQPSK
system.
Direct connection to dual antenna platforms via dual outputs, shown in Figure 20, eliminates losses due to
unnecessary RF power splitters or couplers. Connecting to each antenna results in streamlined, robust installation
and improves Effective Isotropic Radiated Power (EIRP).
Using Space-Time Coding, link outages caused by the "two antenna problem" are eliminated with negligible
bandwidth expansion.
Figure 20: Dual Transmitter RF Outputs Connected to Upper and Lower Antenna
The following example (Figure 21) shows the appropriate dual transmitter connections and expected signal locations
Generation RDMS™ Receiver running in STC mode.
rd
when transmitting to a Quasonix 3
With the PA on the bottom and the dual transmitter facing the user, the left connector corresponds to channel 2
output ("code 2" if referring to the STC constellation display on a Quasonix receiver) and the right connector
corresponds to channel 1 output ("code 1" if referring to the STC constellation display on a Quasonix receiver).
22 Quasonix, Inc.