1. An offset detector for automatic frequency control in a 3GPP wireless communications network, the offset detector comprising: a filter whose amplitude responses are DC-offsetted, odd functions, the filter having an input for receiving a complex gain signal and an output; a delay block comprising an input for receiving the complex gain signal and an output; a first adder electrically connected to the output of the filter and the output of the delay block, the first adder outputting the sum of the output of the filter and the output of the delay block; a second adder electrically connected to the output of the filter and the output of the delay block, the second adder outputting the difference between the output of the filter and the output of the delay block; and a third adder electrically connected to the output of the first adder and to the output of the second adder, the third adder outputting the difference between the output of the first adder and the output of the second adder.