Bit-slice microprocessors in h.f. digital communications

A 2.4 kbit/s baseband modem is being designed for use at h.f., incorporating modulation/demodulation techniques that are matched to those frequencies and the problems associated with them. Fed by a continuous serial datastream, the modulator functions are implemented wholly by a bit-slice microprocessor, and controlled by another more conventional microprocessor. Analogue output waveforms are generated in a d/a converter, which is driven by the bit-slice machine. Demodulation is performed in a similar device, using an a/d input and giving a serial output.