SDR Demonstrator for FDMA Digital Radio

The DE9944 is a compact demonstration/evaluation platform for FDMA Analogue / Digital Radio designs based on the CMX7141 FDMA PMR Processor and incorporating the CMX618 RALCWI Vocoder, the CMX7262 TWELP Professional Radio Vocoder, and the CMX994 Direct Conversion Receiver. Featuring a built in keyboard, display, microphone and speaker, the platform can also be used to demonstrate peer-to-peer operation in a stand-alone configuration.

The board has an ARM processor which handles initial board power up and loading of the Function Images for the CMX7141 and CMX7262. Once the system is powered up, the processor implements a basic radio. The DE9944 provides a Fractional-N PLL and VCO plus associated circuits to provide local oscillator signals for the CMX994.

The design also includes a 1W power amplifier, harmonic filter and Tx/Rx switch. The RF performance is designed to be compliant with EN 301 166 for dPMR application and TIA‑603‑D / EN 300 086 for analogue applications. All the circuits are provided with power-down capability to allow powersave / standby operation.