Multi-Channel Modular All-Digital Transmitter

This paper proposes a novel flexible tile-based multichannel digital architecture of modular Delta-Sigma ($\Delta \Sigma$) AllDigital Transmitters (ADTs) aimed at Multi-User Radio Units (RUs). The proposed design utilizes multiple, less complex $\Delta \Sigma$ ADT operating in parallel, offering flexibility and reconfigurability by enabling various configurations of digital tile-based $\Delta \Sigma$ ADTs channels. Combining multiple tiles of $\Delta \Sigma$-ADTs improves the internal filtering and quantization of the $\Delta \Sigma$-Cores, enabling higher carrier frequencies and better system performance. The proposed architecture was implemented in a Field Programmable Gate Array (FPGA). It achieved a maximum Error Vector Magnitude (EVM) of 8.30% for 800 MHz bandwidth signal in “Quad” configuration with up to 9 GHz carrier frequency and $\mathbf{2. 9 6 \%}$ for 200 MHz bandwidth signal in “Single” configuration with up to 2.5 GHz carrier frequency. The results demonstrate the effectiveness of digital tile-based $\Delta \Sigma$-ADTs modular channels while maintaining the possibility of multiple individual channels when required.