A wide-band time-interleaved A/D converter for cognitive radio application with adaptive offset correction

Analog-to-Digital Converters (ADCs) are critical components of electronic circuits and represent a main bottleneck for realizing high-speed telecommunication systems. Cognitive Radio is one of the paradigms for wireless communication requiring wide-band ADCs. Time-Interleaved ADC (TI-ADC) is an effective candidate for implementation of wide-band receivers. The performance of TI-ADC is practically limited by errors due to mismatches occurring between channels, leading to a considerable degradation in overall resolution. In this paper, a blind adaptive method is proposed to correct offset errors in TI-ADC. The proposed method is verified through applying to a two-channel TI-ADC. Here, Least-Mean-Squares (LMS) algorithm has been exploited to adaptively estimate and correct offset error. Proposed method is structurally very simple and hence suitable for implementation on integrated circuits. This algorithm not only is computationally efficient but also shows an improvement of 28dB in the performance of a two-channel TI-ADC.