Ofdm modulated wave transmitter apparatus, ofdm modulated wave transmission method, and program

Abstract

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 control signal from the OFDM symbol signal; and   an amplifier which amplifies and outputs the OFDM modulated wave signal generated by the OFDM signal generating circuit based on the control signal generated by the control circuit.   
     
     
         2 . The OFDM modulated wave transmitter apparatus according to  claim 1 , wherein the control signal is a power amplifier (PA) control signal. 
     
     
         3 . The OFDM modulated wave transmitter apparatus according to  claim 1 , wherein the power amplifier further includes a converter and a power supply, where
 the control signal s a power supply (PS) control signal,   the converter controls an output voltage of the power supply based on the control signal generated by the control circuit, and   the power amplifier amplifies and outputs the OFDM modulated wave signal based on the output voltage controlled by the converter.   
     
     
         4 . The OFDM modulated wave transmitter apparatus according to  claim 1 , wherein the control circuit further includes a filter for limiting bands of the control signal. 
     
     
         5 . 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. 
     
     
         6 . The OFDM modulated wave transmitter apparatus according to  claim 1 , wherein the control circuit generates the control signal from part of the OFDM symbol signal. 
     
     
         7 . The OFDM modulated wave transmitter apparatus according to  claim 6 , 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. 
     
     
         8 . 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 control signal from the OFDM baseband signal.   
     
     
         9 . The OFDM modulated wave transmitter apparatus according to  claim 3 , wherein:
 the control circuit generates the PS 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 the PS control signal so that a preset output voltage is output from the converter.   
     
     
         10 . An 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 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 the control signal.   
     
     
         11 . A non-transitory computer readable recording medium storing a program for causing a computer for controlling an orthogonal frequency division multiples (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 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 the control signal.