Which of the following is characteristic of QPSK31?
It is sideband sensitive
Its encoding provides error correction
Its bandwidth is approximately the same as BPSK31
All these choices are correct✓پاسخ درست
توضیح
QPSK31 keeps the 31.25 baud Varicode signaling of BPSK31, so its occupied bandwidth is about the same; the extra phase states carry convolutional coding that the receiver uses for error correction; and because decoding depends on the direction of phase rotation, it is sideband sensitive. All three statements hold.