A device implementing signal validation for secure ranging includes at least one processor configured to obtain a channel estimate based at least in part on a signal received from an other device over a channel. The at least one processor may be further configured to determine an average noise level of a beginning portion of the channel estimate and establish a direct path signal acceptance level for the channel estimate based at least in part on the average noise level. The at least one processor may further configured to identify a candidate direct path signal for the channel in a remaining portion of the channel estimate and validate the candidate direct path signal as a direct path signal for the channel when a signal level corresponding to the candidate direct path signal satisfies the direct path signal acceptance level, otherwise reject the candidate direct path signal as the direct path signal for the channel.