A High Efficiency DDC Algorithm for Narrow Band Signal

With the improvement of the performance of ADC, it is available to sample and process real signal in intermediate frequency in radio communication system design. The large source usage and long latency of image-reject filter and decimation in IF DDC are the difficult problems in design. But In many occasions the signal can be processed as narrow band signal. In this paper, we designed an M-points average decimate algorithm to solve these problems in occasion of narrow band signal DDC. The algorithm is implemented in FPGA and its source usage is compared with a common FIR filter design. In the end, an excellent image-reject performance of the algorithm shows the validity of the design.