Application of Golay codes to biomedical transducers for non-invasive measurement

Golay codes have been combined with an experimental piezoelectric transducer in a water bath. It is shown that signal-to-noise-ratio improvements resulting from this are greatest when the input signal-to-noise ratio is greater than unity and the target is obscured by clutter. Further, it is shown that this system can be used to send multiple codes, with code identification after detection, to extend the range-velocity limit in medical Doppler systems. The simple processing involved gives significant improvement in noise performance for no increase in bandwidth against standard maximal length pseudo-random binary systems