An integrated LMS adaptive filter of TX leakage for CDMA receiver front ends

Author

Aparin, Vladimir ; Ballantyne, Gary ; Persico, C. ; Cicalini, Alberto

Author_Institution

QUALCOMM Inc., San Diego, CA, USA

fYear

2005

Firstpage

229

Lastpage

232

Abstract

The theory and practical implementation of an adaptive filter of the TX leakage in CDMA receivers are described. The filter uses a continuous-time signa-data LMS algorithm. It was designed as part of a 0.25 μm CMOS cellular-band receiver. It achieved the maximum rejection of the TX leakage of 28-30 dB, which was limited by the reference signal leakage to the LNA output. The LNA NF and gain degraded by 1.3 dB and 1.7 dB respectively after adding the filter.

Keywords

CMOS integrated circuits; adaptive filters; cellular radio; code division multiple access; continuous time filters; integrated circuit design; integrated circuit measurement; integrated circuit noise; least mean squares methods; radio receivers; radio transmitters; 0.25 micron; CDMA receiver front ends; CMOS cellular band receiver; LNA NF; LNA gain degradation; LNA output; TX leakage; analog multipliers; continuous-time signa-data LMS algorithm; cross modulation distortion; integrated LMS adaptive filter; least squares methods; maximum TX leakage rejection; notch filters; reference signal leakage; Adaptive filters; Degradation; Interference; Laplace equations; Least squares approximation; Matched filters; Multiaccess communication; Radio frequency; SAW filters; Transfer functions;

fLanguage

English

Publisher

ieee

Conference_Titel

Radio Frequency integrated Circuits (RFIC) Symposium, 2005. Digest of Papers. 2005 IEEE

ISSN

1529-2517

Print_ISBN

0-7803-8983-2

Type

conf

DOI

10.1109/RFIC.2005.1489640

Filename

1489640