A signal estimator for an OFDM radio receiver is configured to generate a signal power estimate for a reference signal received on a subcarrier from a plurality of OFDM subcarriers. The signal estimator generates a first channel estimate as a first function of a first set of one or more unfiltered reference-signal channel estimates, where the first set includes an unfiltered reference-signal channel estimate. It generates a second channel estimate as a second function of a second set of one or more unfiltered reference-signal channel estimates, where the second set has no unfiltered reference-signal channel estimate in common with the first set. The signal estimator then generates the signal power estimate by multiplying the first channel estimate with the second channel estimate, such that the generated signal power estimate does not increase with the absolute square of any of the unfiltered reference-signal channel estimates in the first and second sets.