Evaluation of a frequency agile direct RF ADC based on mixed-signal OFDM simulation

Rapid developments and emergence of diverse wireless systems call for radio frontends with agile and multistandard properties. Within this publication the performance of a direct RF digitizing ΣΔ-modulator based analog-to-digital converter (ADC) is evaluated based on orthogonal frequency division multiplex (OFDM) system simulation on the bitstream layer. The necessary transmit and receive building blocks are introduced as well as the previously developed reconfigurable ADC under test. The proposed approach allows flexible testing of different ADCs by analyzing the influence of the ADC´s noise shaping on performance indicators like error vector magnitude (EVM) and symbol error rate (SER). The necessary steps for the combination of the OFDM signal generation and the system level simulation of the ΣΔ-modulator-ADC into a multi-domain simulation are introduced and discussed.