Patent attributes
Techniques for mitigating additional phase noise in local oscillator (LO) signals, which may be due to digital noise coupling, are described. A correction signal having an estimate of additional phase noise in an LO signal is derived. The correction signal is applied to a data signal either after downconversion or before upconversion with the LO signal to mitigate the additional phase noise. To derive the correction signal, an input signal having the additional phase noise may be obtained by downconverting a replica LO signal or based on the replica LO signal without downconversion. The input signal may be digitized and filtered to pass a single tone and suppress remaining tones. A replica signal may be derived based on the filtered signal and frequency translated to obtain a phase noise estimate signal at DC. The complex conjugate of the phase noise estimate signal may be provided as the correction signal.
