All-Digital Transmitter With a Mixed-Domain Combination Filter

In this brief, we present a new reconfigurable filtering technique for all-digital transmitters using signal interference and cancellation. The proposed method allows the change of some filtering characteristics digitally. This technique is used to reduce the quantization noise from the all-digital transmitter's output, reducing the analog output filter requirements. Without a narrow band filter, a greater degree of flexibility for the transmitter's carrier frequency and bandwidth is attained, improving its suitability for multiband and multistandard operation. The results show the quantization noise reduction without an output analog filter, contributing to an increase of the transmitter's coding efficiency up to more than 95%.