DAC Quantization-Noise Cancellation in an Echo-Canceling Transceiver

Data converters, in particular, the transmit digital-to-analog converter (DAC), should not limit performance in a full-duplex digital-communication transceiver. Typically, the number of DAC bits is chosen to be large enough so that the effect of DAC quantization noise on the local receiver is negligibly small. As described in this brief, the DAC quantization noise can be cancelled in an echo-canceling full-duplex transceiver. The proposed quantization-noise cancellation allows use of a simpler, lower resolution DAC. The quantization-noise cancellation concept is described, and simulation results are presented that demonstrate its operation.