Patent ID: 8842033

Claim:
A predistortion generator for reducing distortion in a digital-to-analog converter, the predistortion generator comprising: a sample input to receive digital samples, the digital samples comprising a sequence of current samples, each of the current samples preceded by a respective preceding sample; a summing circuit to output predistorted samples to the digital-to-analog converter, the summing circuit comprising summing circuit inputs, one of the summing circuit inputs connected to the sample input; and distortion term processors, each comprising a product generator and a finite impulse response filter coupled in tandem between the sample input and a respective one of the summing circuit inputs, the product generator to generate a product of samples corresponding to each current sample as a respective distortion term, in which each of the samples corresponding to the current sample is the current sample or a preceding sample corresponding to the current sample, the distortion term processors comprising at least one of: a second-order distortion term processor in which the product generator thereof is to generate a product of only two samples corresponding to the current sample as a respective second-order distortion term, and the FIR filter thereof is to filter each second-order distortion term using a respective FIR filter characteristic, and a third-order distortion term processor in which the product generator thereof is to generate a product of only three samples corresponding to the current sample as a respective third-order distortion term, and the FIR filter thereof is to filter each third-order distortion term using a respective FIR filter characteristic; in which the FIR filter characteristics are configured to reduce distortion in a designated Nyquist zone.