| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a transmission digital filter circuit where the number of necessary multipliers is reduced and to provide a transmission digital filter method. SOLUTION: A first block 1 provided with a first oversampling circuit 11, and a digital filter part 12 by a root Nyquist circuit and a second block 2 provided with a second oversampling circuit 21 and a second digital filter part 22 by a low pass filter circuit are installed. The blocks are divided at least into two sections. The number of chips required for the root Nyquist filter circuit is set to be 16. An input sampling frequency is set to 2.048 MHz and an output sampling frequency to 16.384 MHz. The number of tap coefficient multipliers can be reduced by making the stages of the digital filter parts to be multiple, a gate array executing digital filter processing can be reduced, and the calorific value can be reduced by reducing the multipliers.</p> |
