Patent ID: 7974351

Claim:
A method for detecting a signal, comprising: generating angle information based on a complex signal having a periodic portion; generating an autocorrelation signal based on the angle information and not based on magnitude information associated with the complex signal, where generating the autocorrelation signal includes: generating a first multiplication signal by subtracting from the angle information a delayed-by-N version of the angle information, wherein N is an integer indicative of a period of the periodic portion; generating a second multiplication signal by subtracting from the delayed-by-N version of the angle information a delayed-by-2N version of the angle information; converting the first multiplication signal to a first complex multiplication signal having two components; converting the second multiplication signal to a second complex multiplication signal having two components; subtracting the second complex multiplication signal from the first complex multiplication signal and accumulating the subtraction of the second complex multiplication signal from the first complex multiplication signal; and wherein the method further comprises detecting the periodic portion based on the autocorrelation signal.