METHOD FOR CORRECTING NONLINEARITY OF AMPLIFIER AND RADIO TRANSMITTER USING THE METHOD

摘要

PROBLEM TO BE SOLVED: To use a pre-emphasis table optimum for a signal always communicated by updating the pre-emphasis table based on an average value calculated from the block of the samples of an inputted complex signal and a demodulated complex signal stored in an adaptive period. SOLUTION: The digital signal source 10 outputs a pre-emphasis digital signal from a pre-emphasis device 12, to be D/A-converted and a radio signal d' is outputted from a modulator 16 to be transmitted from a coupler 24 through an antenna 22. Then the coupler 24 samples the fraction r' of a radio signal amplified by the output terminal of an amplifier 20. The signal r' is quadrature demodulated to generate a demodulated complex signal r. The signal r compared with the inputted complex signal in the adaptive period is obtained like this. Then the pre-emphasis table is updated based on the average value calculated from the block of the samples of the inputted signal and the demodulated complex signal stored in the adaptive period.