Baseband analysis of Tx leakage in WCDMA Zero-IF-receivers

Frequency division duplex transceivers employing the zero-if principle suffers from Tx leakage. In this contribution a baseband representation of the Tx leakage impact in zero-if receivers is derived and the statistical properties of the involved baseband signals are analysed. Additionally requirements on the digital compensation of Tx leakage are discussed, based on measurement results of the Tx-Rx isolation of the duplexer as well as properties of the receive branch. Thus, a framework for the digital compensation of Tx leakage at the discrete baseband is presented. Simulation results are used to validate the theoretically predicted spectral shape of the Tx leakage impact and to evaluate the influence of Tx leakage on the system performance.

[1]  Vladimir Aparin,et al.  Analysis and reduction of cross-modulation distortion in CDMA receivers , 2003 .

[2]  Andrea Bevilacqua,et al.  Statistical analysis of second-order intermodulation distortion in WCDMA direct conversion receivers , 2005, IEEE Transactions on Circuits and Systems II: Express Briefs.

[3]  V. Aparin,et al.  An integrated LMS adaptive filter of TX leakage for CDMA receiver front ends , 2005, 2005 IEEE Radio Frequency integrated Circuits (RFIC) Symposium - Digest of Papers.

[4]  Gerhard Fettweis,et al.  A Stochastic Gradient LMS Algorithm for Digital Compensation of Tx Leakage in Zero-IF-Receivers , 2008, VTC Spring 2008 - IEEE Vehicular Technology Conference.

[5]  Maria Huhtala,et al.  Random Variables and Stochastic Processes , 2021, Matrix and Tensor Decompositions in Signal Processing.

[6]  F.J. Harris,et al.  Software defined radio , 2008, 2008 International Conference on Signals and Electronic Systems.

[7]  P.M. Asbeck,et al.  Adaptive duplexer implemented using single-path and multipath feedforward techniques with BST phase shifters , 2005, IEEE Transactions on Microwave Theory and Techniques.

[8]  Danilo Manstretta,et al.  Second-order intermodulation mechanisms in CMOS downconverters , 2003, IEEE J. Solid State Circuits.

[9]  Gerhard Fettweis,et al.  Blind Estimation and Compensation of I/Q Imbalance in OFDM Receivers with Enhancements Through Kalman Filtering , 2007, 2007 IEEE/SP 14th Workshop on Statistical Signal Processing.

[10]  V. Aparin,et al.  Analysis of CDMA signal spectral regrowth and waveform quality , 2001, 2001 IEEE MTT-S International Microwave Sympsoium Digest (Cat. No.01CH37157).

[11]  Athanasios Papoulis,et al.  Probability, Random Variables and Stochastic Processes , 1965 .

[12]  Bruno O. Shubert,et al.  Random variables and stochastic processes , 1979 .

[13]  Thomas H. Lee,et al.  The Design of CMOS Radio-Frequency Integrated Circuits: RF CIRCUITS THROUGH THE AGES , 2003 .