Performance analysis of multilevel delta sigma modulators for 3G/4G communication

Nowadays we are trending towards multi-standard and multiband communication, for that purpose, an efficient modulation method is required to meet the demands of users. In this paper, we analyze the performance enhancement in different types of delta sigma modulator based Transmitters by improving the coding efficiency and signal to noise and distortion ratio (SNDR) using multilevel architecture. Polar delta-sigma modulator is compared to established Cartesian sigma delta modulator. It has been reported that coding efficiency improves from 4.82% to 35.32% for 2 MHz LTE signal and 4.14% to 32.71% for 5 MHz WCDMA signal. Further, multilevel polar delta sigma modulator up to the 5th level is implemented to enhance SNDR while maintaining the good coding efficiency of the polar delta sigma modulation scheme.