TGxA Series Function Generators: PRBS (pseudo-random bit stream) generation up to 50Mbits/s

Pseudo-random bit streams

A PRBS (Pseudo-Random Bit Sequence) is a binary waveform with a sequence that is almost impossible to predict. PRBS waveforms are used within secure communications systems.

A PRBS is generated by a linear-feedback shift register with taps that generate a feedback signal via an exclusive-OR gate. The number of stages determines the sequence length (2N-1) whilst the clock frequency determines the bit rate. The stage length can be set to 7, 9, 11, 15, 20, or 23, resulting in sequence lengths from 127 to 8,388,607 bits at rates between 1µbps to 50Mbps (1µbps to 25Mbps on the TG251xA).

The PRBS waveform can be used as both a carrier and a modulator.