Signal processing device, signal processing method, and non-transitory computer readable medium
A signal processing device according to an example embodiment includes: a distortion compensation circuit configured to execute distortion compensation processing of compensating for nonlinear distortion on an input signal, and output a signal subjected to the distortion compensation processing; an amplifier configured to amplify the signal output from the distortion compensation circuit and output the amplified signal as a communication signal; and a signal output circuit configured to output an adjustment signal for adjusting the distortion compensation processing to the distortion compensation circuit as the input signal at a timing at which the communication signal is not output, the adjustment signal having a frequency band that covers a frequency band of the communication signal.
1. A signal processing device comprising:
a distortion compensation circuit configured to execute distortion compensation processing of compensating for nonlinear distortion on an input signal, and output a signal subjected to the distortion compensation processing;
an amplifier configured to amplify the signal output from the distortion compensation circuit and output the amplified signal as a communication signal for communication; and
a signal output circuit configured to output an adjustment signal for adjusting the distortion compensation processing to the distortion compensation circuit as the input signal at a timing at which the communication signal is not output, the adjustment signal having a frequency band that covers a frequency band of the communication signal.
2. The signal processing device according to claim 1 , wherein the signal output circuit outputs, as the adjustment signal, a signal modulated by orthogonal frequency division multiplexing (OFDM) or spread spectrum.
3. The signal processing device according to claim 1 , wherein the signal output circuit outputs the adjustment signal at a timing that does not overlap with that of a calibration signal output during a calibration operation of the signal processing device.
4. The signal processing device according to claim 3 , wherein
the frequency band of the adjustment signal covers a frequency band of the calibration signal, and
the adjustment signal is output at a timing before the calibration signal.
5. The signal processing device according to claim 1 , further comprising a transmitter between the distortion compensation circuit and the amplifier,
wherein the signal output circuit outputs the adjustment signal in at least one of a period in which the transmitter transitions from off to on before a data slot of the communication signal or a period in which the transmitter transitions from on to off after the data slot of the communication signal.
6. The signal processing device according to claim 1 , wherein the signal output circuit outputs, as the adjustment signal, a signal having a signal peak at a beginning of a signal period.
7. The signal processing device according to claim 1 , wherein the signal processing device is a wireless communication device further comprising wireless transmission circuit for wirelessly transmitting an output signal from the amplifier.
8. The signal processing device according to claim 7 , wherein
the signal processing device comprises a plurality of the amplifiers,
the wireless transmission circuit includes a plurality of antennas corresponding to the plurality of amplifiers, and
the plurality of antennas wirelessly transmit the adjustment signals in such a way that a phase is different between adjacent antennas.
9. A signal processing method comprising:
executing, by a distortion compensation circuit, distortion compensation processing of compensating for nonlinear distortion on an input signal, and outputting a signal subjected to the distortion compensation processing;
amplifying the signal output from the distortion compensation circuit and outputting the amplified signal as a communication signal for communication; and
outputting an adjustment signal for adjusting the distortion compensation processing to the distortion compensation circuit as the input signal at a timing at which the communication signal is not output, the adjustment signal having a frequency band that covers a frequency band of the communication signal.
10. A non-transitory computer readable medium storing a program for causing a computer to perform:
executing, by a distortion compensation circuit, distortion compensation processing of compensating for nonlinear distortion on an input signal, and outputting a signal subjected to the distortion compensation processing;
amplifying the signal output from the distortion compensation circuit and outputting the amplified signal as a communication signal for communication; and
outputting an adjustment signal for adjusting the distortion compensation processing to the distortion compensation circuit as the input signal at a timing at which the communication signal is not output, the adjustment signal having a frequency band that covers a frequency band of the communication signal.