RRH technology with support for simultaneous operation of multiple air-interface protocols is an emerging end-product requirement. The diverse modulation formats and sampling rates between standards such as MC-GSM, WCDMA, and LTE make designing common building blocks, including DUCs and DDCs, challenging. This white paper explores potential filter-chain architectures to simplify simultaneous multimode digital IF processing design, and highlights the productivity and resource utilization tradeoffs between a modular DUC approach and a duplicated DUC approach for a multimode MC-GSM/WCDMA/LTE design.