A voice/data modem for mobile satellite communications

The authors describe the design and performance of a novel voice and data modem developed for mobile satellite communications, offering high speech quality and good intelligibility even for marginal link budgets, together with a coherent data transmission capability resilient to multipath fading and Doppler shift. The modem is implemented using the latest digital signal processing techniques and generates the necessary I/Q signal formats for interfacing to a direct conversion 70MHz transceiver unit.<
>