Patent ID: 8755471

Claim:
A method in a radio apparatus of autonomously detecting whether a reference signal within an OFDM signal transmitted by a remote transmitter is muted for a given transmission time, the method comprising: receiving the OFDM signal; calculating a first comparison metric from signal samples of the OFDM signal corresponding to a first set of resource elements of the OFDM signal; calculating a second comparison metric from signal samples of the OFDM signal corresponding to a second set of resource elements of the OFDM signal; determining whether the reference signal is muted by the remote transmitter over the given transmission time by comparing the first and second comparison metrics; and performing reference signal measurements responsive to determining that the reference signal is not muted, or forgoing reference signal measurements at least for any resource elements of the reference signal that are determined to be muted; wherein calculating the first comparison metric comprises determining first correlation results by correlating the OFDM signal as received on the first set of resource elements with a known reference signal pattern; wherein calculating the second comparison metric comprises determining second correlation results by correlating the OFDM signal as received on the second set of resource elements with the known reference signal pattern; and wherein determining whether the reference signal is muted over the given transmission time further comprises: determining a difference between the first and second correlation results; comparing that difference to a defined threshold; and determining that the reference signal is not muted if the difference exceeds the defined threshold, otherwise determining that the reference signals is muted.