CONTROLLABLE FREQUENCY OFFSET FOR INPHASE AND QUADRATURE (IQ) IMBALANCE ESTIMATION

摘要

Embodiments of user equipment and methods for determining IQ imbalance parameters are described. In some embodiments, a method for determining in-phase (I) and Quadrature (Q) imbalance (IQ imbalance) parameters based on a known signal in a dual-carrier receiver using at least one controllable frequency offset includes receiving a known signal modulated onto a first radio frequency (RF) carrier frequency and a second RF carrier frequency different than the first RF carrier frequency. The known signal is downconverted to a baseband signal for the carriers by conversion from the respective RF carrier frequencies to an intermediate frequency (IF) using a common RF local oscillator (LO) and by further conversion from IF to baseband using carrier specific IF LOs, where a controllable frequency offset is used. Any controllable frequency offset is removed from the baseband signal for the first and second carriers to produce representations of the received signals.

主权项

1. A method for determining in-phase (I) and Quadrature (Q) imbalance (IQ imbalance) parameters based on a known signal in a dual-carrier receiver using at least one controllable frequency offset, the method comprising:
receiving the known signal modulated onto a first radio frequency (RF) carrier frequency and a second RF carrier frequency different than the first RF carrier frequency; down converting the known signal to a baseband signal for each of the first and second carrier frequencies by conversion from the respective RF carrier frequencies to an intermediate frequency (IF) using an RF local oscillator (LO) and by further conversion from IF to baseband using carrier specific IF LOs, wherein a controllable frequency offset is used as a part of the conversion from at least one of RF to IF and IF to baseband through the LOs; removing any controllable frequency offset from the baseband signal for each of the first and second carrier frequencies to produce representations of the received signals of the first and second carrier frequencies, wherein the controllable frequency offset is removed using a mixer; and deriving IQ imbalance parameters based upon each representation of the received signals of the first and second carrier frequencies.