Calibration of a synthesiser in a radio receiver

A radio receiver device arranged to receive a plurality of data symbols transmitted on one or more frequencies from a predetermined set of frequencies, said radio receiver device comprising a synthesiser, wherein the radio receiver device is arranged to:

• receive a first set of data symbols at a first transmission frequency, wherein said first set of data symbols comprises a message indicating a first frequency sub-set comprising one or more frequencies selected from said predetermined set of frequencies;
• calibrate the synthesiser for the one or more frequencies in said first frequency sub-set;
• receive a second set of data symbols transmitted on at least one of said one or more frequencies from the first sub-set;
• determine from the second set of data symbols whether a network quality metric exceeds a threshold;
• and
• calibrate the synthesiser for one or more frequencies in a second frequency sub-set when the network quality metric exceeds the threshold, wherein the second frequency sub-set comprises frequencies of the predetermined set of frequencies that are not in the first frequency sub-set.

A radio communication system comprising a radio transmitter device and a radio receiver device, wherein:

• the radio transmitter device comprises a synthesiser and is arranged to transmit a plurality of data symbols on one or more frequencies from a predetermined set of frequencies;
• wherein the radio receiver device is further arranged to:
• receive a first set of data symbols at a first transmission frequency, wherein said first set of data symbols comprises a message indicating a first frequency sub-set comprising one or more frequencies selected from said predetermined set of frequencies;
• calibrate the synthesiser for the one or more frequencies in said first frequency sub-set;
• receive a second set of data symbols transmitted on at least one of said one or more frequencies from the first sub-set;
• determine from the second set of data symbols whether a network quality metric exceeds a threshold;
• and
• calibrate the synthesiser for one or more frequencies in a second frequency sub-set when the network quality metric exceeds the threshold, wherein the second frequency sub-set comprises frequencies of the predetermined set of frequencies that are not in the first frequency sub-set.