Transmitter and transmission method

摘要

A transmitter is capable of suppressing a PAPR to be low and efficiently amplifying transmit power. The transmitter generates a transmission signal by oversampling a modulated signal, and includes a modulation unit that performs a modulation process on an information sequence and that generates a constant envelope signal and a phase interpolation unit that inserts a predetermined number of signals identical in amplitude to signal points of the constant envelope signal between the signal points so that signal points including original signal points are located equidistantly.

主权项

1. A transmitter that generates a transmission signal by oversampling a modulated signal, the transmitter comprising:
a modulator that performs a modulation process on an information sequence and that generates a constant envelope signal; an interpolator that inserts a predetermined number of signals identical in amplitude to signal points of the constant envelope signal between the signal points so that signal points including original signal points are located equidistantly; a Fourier transformer that transforms a signal obtained after the interpolator has performed a signal insertion process into a frequency-domain signal; a band-limiting filter that performs band limitation on a frequency-domain signal output from the Fourier transformer; an adder that adds an out-of-band signal that is a signal cut by the band-limiting filter to an in-band signal that is a signal not cut by the band-limiting filter; and an inverse Fourier transformer that transforms a signal obtained after the adder has performed an addition process into a time domain signal, wherein the adder performs addition to the in-band signal by individually frequency-shifting components of the out-of-band signal based on respective distances to the in-band signal on a frequency axis and by adding the frequency-shifted components to the in-band signal.