The integrator technique of time delay measurement has already been found to be very useful, in view of its simplicity, attractive analytical properties and the picosecond sensitivities that are attainable. This paper evaluates the integrator technique within the general context of time delay estimation. The noise performance of the integrator technique is evaluated and a comparison is made with the Cramer-Rao bound. It is shown that the Cramer-Rao bound is approached within a factor of 2.

Improved efficiency multilevel partial response systems have recently been discovered. They are superior to conventional partial response systems when operated above the Nyquist signaling rate. This behavior has not as yet been explained and this correspondence gives a concise analysis, which shows the reason for the superior performance.

A new formula for the group delay of a network is derived. The formula is not restricted to narrow-band signals and is valid up to quite large bandwidths. A simple and very sensitive technique for group delay measurement, based on this new relation, is described.

New time-domain formulas for the attenuation dispersiond\alpha/ d\omegaand group delay dispersiond^{2}\phi/d\omega^{2}of a transmission path are derived. It is shown how they can be used to measured\alpha/d\omegaandd^{2}\phi/d\omega^{2}accurately. The formulas involve only output quantities and thus can be used for measurements on very long transmission paths, where the input and output are not simaltaneously accessible.