METHODS AND APPARATUSES FOR ESTIMATION AND COMPENSATION OF NONLINEARITY ERRORS

摘要

An estimator estimates a nonlinearity error of an ADC processing a signalbandlimited between .omega.1(L-1).pi./T and .omega.2L.pi./T, L being aninteger, and T being an ADCsample period. The estimator receives a digital input signal and outputs adigital estimatederror signal, both having a first sample rate. For each of multiple integers P_k, the estimatorcomprises a first filter unit generating a first signal s1(n) as a linearfunction of the inputsignal, an interpolator interpolating the first signal s1(n) to generate asecond signal s2(m)having a second sample rate a factor L.cndot.R_k higher than the first samplerate, whereinL.cndot.R_k=.omega.2.cndot.T.cndot.P_k/.pi., a nonlinearity unitgenerating a third signal s3(m) as (s2(m))P_k, and asecond filter unit generating a component of the estimated error signal basedon the thirdsignal s3(m), said component having the first sample rate. The estimated errorsignal isgenerated by summing said components.