Abstract: A scheme for estimating the carrier-to-noise-plus-interference ratio (CNIR) for Orthogonal Frequency-Division Multiplexing (OFDM) waveforms makes use of a physical waveform frame structure including a diversity selection portion. The diversity selection portion may be located at the end of a burst as a postamble and includes one or more OFDM symbols each having a frequency bin structure including both non-zero and zero OFDM frequency bin content. A first set of measurements are taken from an antenna branch on the non-zero OFDM frequency bins, and a second set of measurements are taken from the antenna branch on the zero OFDM frequency bins. An estimate for CNIR for at least one of the non-zero OFDM frequency bins and at least one of the zero OFDM frequency bins of the antenna branch is then computed using the first and second set of measurements.