Wireless communication apparatus
A transmission RF section ( 101 ) up-converts a DA-converted test signal into a high-frequency signal. An amplitude of the high-frequency signal, an envelope of which is detected by a loop-back section, is detected by an amplitude detector ( 400 ). An inverse characteristic calculator ( 402 ) converts the detected amplitude into an amplitude in the transmission RF section ( 101 ) using an inverse conversion table ( 407 ) and then calculates amplitude inverse characteristics. An FIR filter ( 103 ) corrects a signal band of a transmission signal based on a result of an inverse Fourier transform calculated by an IFFT section ( 405 ) based on the amplitude inverse characteristics as a variable factor.
1. A wireless communication apparatus comprising:
a modulator, configured to generate a broadband transmission signal;
a test signal generator, configured to iteratively generate a sequence of test signals, the sequence of test signals each having a respectively different frequency component within a channel of the broadband transmission signal;
a Digital to Analog (DA) converter, configured to perform a DA conversion of the generated sequence of test signals and the broadband transmission signal;
a transmission Radio Frequency (RF) section, configured to up-convert the sequence of DA-converted test signals into a sequence of high-frequency test signals, and up-convert the DA-converted broadband transmission signal into a high-frequency broadband transmission signal;
a transmission antenna, configured to transmit the high-frequency broadband transmission signal;
a reception antenna, configured to receive a second high-frequency broadband transmission signal;
a loop-back section, configured to perform an envelope detection of the sequence of high-frequency test signals;
an Analog to Digital (AD) converter, configured to perform an AD conversion of the envelope detected sequence of test signals inputted from the loop-back section;
an amplitude detector, configured to detect an amplitude component of each of the AD-converted sequence of test signals with respect to the different frequency components of the iteratively generated sequence of test signals;
an inverse characteristic calculator, configured to calculate amplitude inverse characteristics of the AD-converted sequence of test signals based on characteristics of the detected amplitude components;
an IFFT calculator, configured to perform an inverse Fourier transformation of the calculated amplitude inverse characteristics; and
a Finite Impulse Response (FIR) filter, configured to correct an amplitude of each of the frequency components, within the channel, of the broadband transmission signal based on variable factors, the variable factors being the results of the inverse Fourier transformation of the calculated amplitude inverse characteristics.
2. The wireless communication apparatus according to claim 1 , further comprising:
a second loop-back section, configured to input the sequence of high-frequency test signals to a reception RF section;
the reception RF section, configured to down-convert the sequence of high-frequency test signals into a sequence of received baseband-frequency test signals, and down-convert the received second high-frequency broadband transmission signal into a received baseband-frequency broadband transmission signal;
the AD converter further configured to perform AD conversion of the sequence of received baseband-frequency test signals, and perform AD conversion of the received baseband-frequency broadband transmission signal; and
a second FIR filter, configured to correct a signal band of the AD-converted received baseband-frequency broadband transmission signal, the correction of the signal band of the AD-converted received baseband-frequency broadband transmission signal is based on the variable factors or the AD converted sequence of received baseband-frequency test signals.
3. The wireless communication apparatus according to claim 1 , wherein:
the iteratively generated sequence of test signals are tone waves, and
the envelope detected sequence of test signals are DC signals.
4. The wireless communication apparatus according to claim 1 , wherein adjoining frequency components of the iteratively generated sequence of test signals within the channel of the broadband transmission signal have an equal frequency interval with respect to each other.
5. The wireless communication apparatus according to claim 1 , wherein the FIR filter corrects the amplitude of each of the frequency components to obtain constant amplitude characteristics with respect to the broadband transmission signal.