$SigmaDelta$ADC-Based Frequency-Error Measurement in Single-Carrier Digital Modulations

This paper deals with the functional-block architecture implementing the new method to measure the carrier frequency error of the single-carrier digital modulations. The method is able to operate on the modulations M-ary amplitude shift keying, M-ary phase shift keying, and M-ary quadrature amplitude modulation used in the telecommunication systems. The functional-block architecture obtained from the software-radio (SR) architecture is based on the cascade of the analog-to-digital converter (ADC), the digital down converter, and the base-band processing. Looking at the implementation in measurement instrumentation, the performance of this cascaded architecture is investigated by considering three different ADC architectures. They are based on 1) pipeline; 2) single quantizer loop Sigma-Delta (SigmaDelta) modulator; and 3) multistage noise shaper (MASH) SigmaDelta modulator. Numerical tests confirm the important rule of the ADC in this architecture and highlight the interesting performance of the MASH-based SigmaDelta modulator for use in advanced measurement instruments