Title :
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
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;
Conference_Titel :
Radio Frequency integrated Circuits (RFIC) Symposium, 2005. Digest of Papers. 2005 IEEE
Print_ISBN :
0-7803-8983-2
DOI :
10.1109/RFIC.2005.1489640
