Frequency offset estimation

A receiver system comprising:

• a matched filter bank;
• decision logic;
• and
• a frequency offset estimator,
• wherein:
• the matched filter bank comprises an input for receiving data representative of a frequency- or phase-modulated signal;
• the decision logic is configured to generate a sequence of demodulated symbol values from outputs of the matched filter bank;
• the frequency offset estimator is configured to:
• determine a first phase value from a first output of the matched filter bank;
• determine a second phase value from a second output of the matched filter bank, wherein the second output is offset from the first output by an offset number, L, of symbol periods;
• determine a phase adjustment value from an L-symbol subsequence within the sequence of demodulated symbol values, wherein each of the L symbol values is determined at least in part from a respective one or more values output by the matched filter bank during a time interval from the first output to the second output;
• and
• generate a frequency offset estimate by estimating a frequency offset in dependence on the difference between i) the first phase value plus the phase adjustment value and ii) the second phase value.