On the concept of a Multi-Standard Wireless Receiver enhanced with a Digital-Front-End

This paper describes a possible solution to receive different radio access technologies (RAT) like UMTS and IS95 with one reconfigurable Radio Frequency (RF) front-end. To achieve this, the well known direct conversion receiver (DCR) architecture is enhanced with a Digital-Front-End (DFE). This decreases the requirements for the analog part because channelization and fine frequency tuning are shifted from the analog into the digital domain. The DFE includes highly reconfigurable filter structures, which enable channel selection for different signal bandwidths according to the configured RAT. The analog to digital conversion is carried out with a high dynamic-range/low-power -analog-to-digital-converter (ADC). To satisfy the requirements of different digital base band integrated circuits (BB-IC) and to expand the flexibility the DFE also carries out a fractional sample rate conversion (FSRC). The DFE concept allows shifting some of the analog functions to the digital domain within the radio frequency integrated circuit (RF-IC).