OFDM modulated wave transmitter apparatus, OFDM modulated wave transmission method, and program
View Patent ↗In an orthogonal frequency division multiplex (OFDM) modulated wave transmitter apparatus, a symbol mapping circuit and a serial/parallel (S/P) converter generate an OFDM symbol signal from transmission data. An inverse fast Fourier transform (IFFT) circuit, a parallel/serial (P/S) converting and guard interval (GI) adding circuit, a timing adjusting circuit, a digital/analog (D/A) converter, a frequency converter, a local oscillator and an analog filter generate an OFDM modulated wave signal from the OFDM symbol signal. A power amplifier (PA) control circuit limits a band of the OFDM symbol signal and generates a PS control signal and a PA control signal. A PA designates a voltage supplied from a DC/DC converter as a PS voltage and amplifies and outputs the OFDM modulated wave signal based on the PA control signal.
1. An orthogonal frequency division multiplex (OFDM) modulated wave transmitter apparatus comprising:
an OFDM symbol signal generating circuit which generates an OFDM symbol signal from transmission data;
an OFDM signal generating circuit which generates an OFDM modulated wave signal from the OFDM symbol signal;
a control circuit which generates a power supply (PS) control signal and a power amplifier (PA) control signal from the OFDM symbol signal;
a converter which controls an output voltage of a PS based on the PS control signal generated by the control circuit; and
an amplifier which amplifies and outputs the OFDM modulated wave signal generated by the OFDM signal generating circuit based on at least one of the output voltage controlled by the converter and the PA control signal generated by the control circuit.
2. The OFDM modulated wave transmitter apparatus according to claim 1 , wherein the control circuit further includes a filter for limiting bands of the PS control signal and the PA control signal.
3. The OFDM modulated wave transmitter apparatus according to claim 1 , wherein the OFDM symbol signal generating circuit generates an OFDM symbol signal having a subcarrier arrangement to prevent non-linear distortion from being generated.
4. The OFDM modulated wave transmitter apparatus according to claim 1 , wherein the control circuit generates the PS control signal and the PA control signal from part of the OFDM symbol signal.
5. The OFDM modulated wave transmitter apparatus according to claim 4 , wherein the control circuit includes an inverse fast Fourier transform (IFFT) circuit for bypassing a calculation path in which multiplication of 0 occurs when symbol information of some subcarriers is subjected to an IFFT.
6. The OFDM modulated wave transmitter apparatus according to claim 1 , wherein:
the OFDM signal generating circuit generates an OFDM baseband signal from the OFDM symbol signal, and generates the OFDM modulated wave signal from the OFDM baseband signal, and
the control circuit generates the PS control signal and the PA control signal from the OFDM baseband signal.
7. The OFDM modulated wave transmitter apparatus according to claim 6 , wherein the control circuit further includes a filter for limiting bands of the PS control signal and the PA control signal.
8. The OFDM modulated wave transmitter apparatus according to claim 1 , wherein:
the control circuit generates the PS control signal and the PA control signal from the OFDM symbol signal based on whether or not the OFDM modulated wave signal is within a band capable of being followed, and
the control circuit invalidates a control of the PS output voltage according to the converter if the OFDM symbol signal exists outside the band capable of being followed, and generates a power control signal so that a preset output voltage is output from the converter.
9. An orthogonal frequency division multiplex (OFDM) modulated wave transmission method comprising:
generating an OFDM symbol signal from transmission data;
generating an OFDM modulated wave signal from the OFDM symbol signal;
generating a power supply control signal and a power amplifier control signal from the OFDM symbol signal;
controlling an output voltage of a power supply based on the power supply control signal; and
amplifying and outputting the OFDM modulated wave signal based on at least one of the controlled output voltage and the power amplifier control signal.
10. A non-transitory computer readable recording medium storing a program for causing a computer for controlling an orthogonal frequency division multiplex (OFDM) modulated wave transmitter apparatus to execute:
an OFDM symbol signal generating function of generating an OFDM symbol signal from transmission data;
an OFDM signal generating function of generating an OFDM modulated wave signal from the OFDM symbol signal;
a control function of generating a power supply control signal and a power amplifier control signal from the OFDM symbol signal;
a converting function of controlling an output voltage of a power supply based on the power supply control signal; and
an amplifying function of amplifying and outputting the OFDM modulated wave signal based on at least one of the controlled output voltage and the power amplifier control signal.
11. The OFDM modulated wave transmitter apparatus according to claim 2 , wherein the OFDM symbol signal generating circuit generates an OFDM symbol signal having a subcarrier arrangement to prevent non-linear distortion from being generated.