A Blind Interference Canceling Technique for Two-Stage Harmonic Rejection in Down-mixers
نویسندگان
چکیده
This paper presents practical experiments on a harmonic rejection down-mixer, which offers up to 75 dB of harmonic rejection, without an RF filter. The down-mixer uses a two-stage approach; the first stage is an analog multi-path/multiphase harmonic rejection mixer followed by a second stage providing additional harmonic rejection based on blind adaptive interference canceling in the discrete-time domain. The aim is to show its functional operation. The canceler cannot cope with DC offsets. The DC offsets are removed by highpass filters. The signal paths used to obtain an estimate of the interference must be designed to provide as much attenuation of the desired signal as possible. Front-end nonlinearities and DC offsets are discussed.
منابع مشابه
Frequency Translation Loops for RF Filtering Theory and Design
Modern wireless transceivers are required to operate over a wide range of frequencies in order to support the multitude of currently available wireless standards. Wideband operation also enables future systems that aim for better utilization of the available spectrum through dynamic allocation. As such, co-existence problems like harmonic mixing and phase noise become a main concern. In particu...
متن کاملEstimation of harmonic interference parameters of surface-NMR signal using an adaptive method and residual signal power
Surface nuclear magnetic resonance (surface-NMR) method is a well-known tool for determining the water-bearing layers and subsurface resistivity structure. Harmonic interference is an inevitable interference in surface-NMR measurements. Accurate estimation of harmonic interference parameters (i.e., fundamental frequency, phase and amplitude) leads to better retrieval of power-line harmonics and...
متن کاملA New Analog-based LO Harmonic Rejection Technique with Tunable Notch Frequency
An effective technique for mixer LO harmonic rejection in a SAW-less wideband receiver front-end is proposed. The proposed technique provides a tunable notch that can be placed at any frequency like mixer LO harmonics, to avoid the aliasing in baseband after mixing. An analog LC notch is used in a cascode transconductor, and it can reject one of the 3rd or 5th harmonics. T...
متن کاملINTELLIGENT TECHNIQUE OF CANCELING MATERNAL ECG IN FECG EXTRACTION
In this paper, we propose a technique of artificial intelligence called adaptive neuro fuzzy inference system (ANFIS) for canceling maternal electrocardiogram (MECG) in fetal electrocardiogram extraction (FECG).This technique is used to estimate the MECG present in the abdominal signal of a pregnant woman. The FECG is then extracted by subtracting the estimated MECG from the abdominal signal. P...
متن کاملHigh quality signal reception in the presence of stationary interference-a blind signal separation approach
This paper considers the problem of interference rejection using sensor array with application to enhance signal reception. In contrast to conventional adaptive beamforming which requires knowledge of the array geometry and array response, we propose a two stage blind signal separation approach to achieve interference rejection. The proposed method is based on the practically viable assumptions...
متن کامل