Patent ID: 8634453

Claim:
A method for performing carrier phase and frequency offset correction on samples x 1 (n) of a received signal, wherein n is a time index, wherein the received signal includes a series of frames, wherein each frame includes a preamble and payload data, wherein the preamble of each frame includes multiple repetitions of a base pattern, wherein the multiple repetitions of the base pattern conform to a first constant-amplitude continuous-phase frequency modulation scheme, the method comprising: a computer system applying a first frequency correction to the samples x 1 (n) based on a coarse estimate for a carrier frequency offset in order to determine samples x 2 (n); the computer system computing values θ(p) of a function θ for a number of values of positive integer index p, said number of values being greater than one, wherein θ(p) is a phase difference between a first subsequence of the samples x 2 (n) and a second subsequence of the samples x 2 (n), wherein the first and second subsequences reside within a first of the preambles, wherein the first and second subsequences are separated by a sample distance equal to p repetitions of the base pattern; the computer system computing a fine estimate for residual carrier frequency offset by estimating a linear slope of the function θ relative to the positive integer index p; the computer system applying a second frequency correction to the samples x 2 (n) based on the fine estimate for the residual carrier frequency offset in order to determine samples x 3 (n); the computer system computing a complex inner product between a model sequence g(n) and a subsequence of the samples x 3 (n), wherein the subsequence of the samples x 3 (n) resides within the first preamble, wherein the model sequence g(n) corresponds to a subsequence of a known model of the multiple repetitions of the base pattern; the computer system applying a phase correction to the samples x 3 (n) based on an angle of the inner product in order to obtain samples x 4 (n).