Blind mechanism for the joint estimation of frequency offset and phase offset for QAM modulated signals
2010 (English)Patent (Other (popular science, discussion, etc.))
A mechanism for jointly correcting carrier phase and carrier frequency errors in a demodulated signal. A computer system may receive samples of a baseband input signal (resulting from QAM demodulation). The computer system may compute values of a cost function J over a grid in a 2D angle-frequency space. A cost function value J(theta,omega) is computed for each point (theta,omega) in the grid by (a) applying a phase adjustment of angle theta and a frequency adjustment of frequency omega to the input signal; (b) performing one or more iterations of the K-means algorithm on the samples of the adjusted signal; (c) generated a sum on each K-means cluster; and (d) adding the sums. The point (thetae,omegae) in the 2D angle-frequency space that minimizes the cost function J serves an estimate for the carrier phase error and carrier frequency error.; The estimated errors may be used to correct the input signal.
Place, publisher, year, edition, pages
Electrical Engineering, Electronic Engineering, Information Engineering Signal Processing
IdentifiersURN: urn:nbn:se:kth:diva-120151OAI: oai:DiVA.org:kth-120151DiVA: diva2:613713
US 8446974-B2 (2013-05-21)
US8755470-B2 (2014-06-17)2013-04-012013-04-012014-11-10Bibliographically approved