| 摘要 |
A digital signal transmitting apparatus (1), a digital signal transmitting method, and a digital signal transmitter-receiver, for transmitting a digital signal within a specified frequency band by using an infrared transmission method. An infrared signal within a specified frequency band can be obtained by using a QPSK modulation circuit 13 having roll-off filters 132 and 133 and applying roll-off filtering and QPSK modulation to an inputted digital audio signal, and thereby generating a digital modulated signal S2 whose bandwidth is narrowed and driving an infrared emitter (4) based on the modulated digital audio signal S2. <MATH> |
