54 Description TM9100 Service Manual© Tait Electronics Limited August 20052.6 Operation in Transmit ModeOverview This section describes the functioning of the transceiver in transmit mode.The operation of the transceiver is illustrated in Figure 2.12 on page 48(analog mode) and Figure 2.13 on page 49 (digital mode).These block diagrams show the hardware modules integrated with thesoftware modules:■ hardware (transmitter, receiver, CODEC and audio)■ RISC processor (on FPGA of digital board)■ custom logic (on FPGA of digital board)■ DSP block (on digital board)Note The block diagrams for the analog and digital modes only differ inthe operation of the DSP.The transmit path consists of three major functional parts:■ audio processing and signaling■ frequency synthesizer■ RF transmitterNote The information flow on a digital radio can be categorized in twoforms, signaling (including user data) and voice. Whilst setting upa call, signaling may be the only information transferred across theair interface. Once a call has been established however, both sig-naling and voice information are transported. The signaling infor-mation continues throughout the call for the purpose of maintain-ing the call and possibly sending data information.
