A high-resolution link-path delay estimator to estimate a signal-path delay of a signal path between a master device and a remote device, the high-resolution link-path delay estimator comprising: a delay element to delay a transmit signal by one of a plurality of delay values, the transmit signal comprising a waveform of alternating symbols; a sampler to sample a loopback signal on edges of the delayed transmit signal to generate a sampled signal output, the loopback signal being a delayed version of the transmit signal that is returned from the remote device; a noise-reduction element arranged to generate a noise-reduced output from the sampled signal output, the noise-reduction element being arranged to use multiple sampled signal outputs taken at a common one of the delay values from the sampler to produce the noise-reduced output; a correlation element to correlate the noise-reduced output with a step function which models a noiseless transition of the sampled signal output to generate a correlation value for each of the delay values; and a controller to instruct the delay element to delay the transmit signal by a selected one of the delay values and generate a fine-time data output based on the correlation value, the fine-time data output being an indicator of the signal-path delay to within a fraction of a symbol period of the transmit signal; wherein the delay element comprises a phase-shifter to phase-shift the transmit signal by one of a plurality of phase-shift values; and each of the phase-shift values are a fraction of the symbol period of the transmit signal, the plurality of phase-shift values together comprise up to one symbol period of the transmit signal; wherein the controller is configurable to cause the phase-shifter to shift through a plurality of the phase-shift values and select one of the phase-shift values that provides either a maximum correlation value or a correlation value above a threshold to generate the fine-time data output corresponding to the selected phase-shift value. a delay element to delay a transmit signal by one of a plurality of delay values, the transmit signal comprising a waveform of alternating symbols; a sampler to sample a loopback signal on edges of the delayed transmit signal to generate a sampled signal output, the loopback signal being a delayed version of the transmit signal that is returned from the remote device; a noise-reduction element arranged to generate a noise-reduced output from the sampled signal output, the noise-reduction element being arranged to use multiple sampled signal outputs taken at a common one of the delay values from the sampler to produce the noise-reduced output; a correlation element to correlate the noise-reduced output with a step function which models a noiseless transition of the sampled signal output to generate a correlation value for each of the delay values; and a controller to instruct the delay element to delay the transmit signal by a selected one of the delay values and generate a fine-time data output based on the correlation value, the fine-time data output being an indicator of the signal-path delay to within a fraction of a symbol period of the transmit signal; wherein the delay element comprises a phase-shifter to phase-shift the transmit signal by one of a plurality of phase-shift values; and each of the phase-shift values are a fraction of the symbol period of the transmit signal, the plurality of phase-shift values together comprise up to one symbol period of the transmit signal; wherein the controller is configurable to cause the phase-shifter to shift through a plurality of the phase-shift values and select one of the phase-shift values that provides either a maximum correlation value or a correlation value above a threshold to generate the fine-time data output corresponding to the selected phase-shift value.