Patent ID: 7969939

Claim:
A method of determining a signal quality parameter for a signal received by a device operating in a wireless communications network, wherein the device receives a signal comprising a plurality of physical channels, said method including: determining two signal parameters, on the basis of measurements made on at least one of said plurality of physical channels; determining a calibration parameter indicative of variations common to the signal parameters; and determining the signal quality parameter on the basis of said two signal parameters and said calibration parameter, wherein said two parameters are an interference signal code power (ISCP) and a received signal code power (RSCP), wherein said calibration parameter is the RSCP determined from a different channel of said plurality of physical channels to said two signal parameters, and in said step of determining the signal quality parameter, dividing both the RSCP and the ISCP by the calibration parameter to remove most of the common variation, smoothing the ISCP, and calculating the signal quality parameter by using the following expression: S ⁢ ⁢ I ⁢ ⁢ R = R ⁢ ⁢ S ⁢ ⁢ C ⁢ ⁢ P t C t Smoothed_ISCP t where SIR is the signal quality parameter, Smoothed ISCP t is the smoothed ISCP, and C t is the calibration parameter.