Normalized LMS Adaptive Cancellation of Self-Image in Direct-Conversion Receivers

作者：Gil Gye Tae^*

来源：IEEE Transactions on Vehicular Technology, 2009, 58(2): 535-545.

DOI：10.1109/TVT.2008.925310

• Adaptive filter
• direct conversion
• in-phase/quadrature-phase (I/Q) mismatch
• interference cancellation

This paper presents an adaptive digital signal processing technique that cancels self-image interference due to frequency-independent, in-phase/quadrature-phase (I/Q) mismatch in zero-intermediate frequency (IF) direct-conversion receivers. The proposed technique, which is referred to as the normalized least-mean square adaptive self-image cancellation (NLMS-ASIC) algorithm, is an ASIC technique that controls the filter weight to minimize the power of the filter output signal using an NLMS type of weight-control mechanism. Some closed-form equations are derived for the mean-squared error (MSE), as well as the mean image-rejection ratio (IRR) of the proposed NLMS-ASIC algorithm. In particular, a step-size determination method is explained so that the requirements on the image-rejection performance and convergence time can be satisfied. The advantages of the proposed technique are demonstrated through computer simulations.

• 出版日期2009-2