Front Panel; Baseband Processing; Tx Baseband Processing - Radyne DMD20 Installation And Operation Manual

Theory of Operation DMD20/DMD20 LBST Universal Satellite Modem
Figure 3-4. DMD20 Universal Satellite Modem Functional Block Diagram

3.1.1 Front Panel

The Front Panel includes a 2 x 16 backlit LCD Display, Indicator LEDs, and a Numeric Keypad
(refer to Section 4.1).

3.1.2 Baseband Processing

The Baseband Processor performs all of the functions required for an IBS/IDR Framing Unit, a
Reed-Solomon Codec, and an E1/T1 Drop and Insert System. In addition, the Baseband
Processing Section provides for transmit clock selection and rate adaptation as well as a rate
adapter and Plesiochronous/Doppler (PD) Buffer in the receive direction. A multiplexer is also
provided for the SCT Clock Source for Loop Timing Applications. The transmit and receive paths
may be configured independently under processor control.

3.1.3 Tx Baseband Processing

The Tx Data and Clock enters the Baseband Processor, passes through a Rate Adapting FIFO
and enters the Framer/Drop Processor. In Closed-Net Mode, the data passes through the framer
3-4 TM103 - Rev. 2.5