Transmitter
AssigneeMatsushita Electric Industrial Co., Ltd.
InventorsAkihiko Matsuoka, Masayuki Orihashi, Morikazu Sagawa, Kenichi Takahashi, Kouei Misaizu
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Abstract
Nonlinear distortion compensating data is calculated by approximation equations at a compensating coefficient calculation section using an amplitude value of transmission quadrature base band signals obtained by a power calculating section, wherein by carrying out nonlinear distortion compensation at a nonlinear distortion compensating section using the data, it is possible to compensate nonlinear distortion generated in an amplifier of the transmission system without use of any memory table, and a nonlinear distortion compensating section can be obtained, which has a great effect of decrease distortion.
Claims28
A transmission apparatus comprising:
- a first amplitude calculating means for calculating a first amplitude value of a transmission quadrature base band signals;
- an amplitude limiting table for storing amplitude limiting information corresponding to said first amplitude value;
- a first amplitude limiting means for limiting the amplitude of said transmission quadrature base band signals using said amplitude limiting information;
- a quadrature modulating means for modulating the amplitude limited transmission quadrature base band signals to output a radio frequency (RF) signals;
- and
- amplifying means for amplifying said RF signals.
A transmission apparatus comprising:
- first amplitude calculating means for calculating a first amplitude value from transmission quadrature base band signals;
- limiting coefficient calculating means for calculating an amplitude limiting coefficient with respect to said first amplitude value;
- first amplitude limiting means for limiting the amplitude of said transmission quadrature base band signals using said amplitude limiting coefficient;
- quadrature modulating means for quadrature modulating the amplitude-limited transmission quadrature base band signals to output RF signals;
- and
- amplifying means for amplifying said RF signals.
A transmission apparatus comprising:
- a first amplitude calculator that calculates a first amplitude value of transmission quadrature base band signals;
- an amplitude limiting table that stores amplitude limiting information corresponding to said first amplitude value;
- a first amplitude limiter that limits the amplitude of said transmission quadrature base band signals using said amplitude limiting information;
- a quadrature modulator that modulates the amplitude limited transmission quadrature base band signals to output radio frequency signals;
- and
- an amplifier that amplifies said radio frequency signals.
A transmission apparatus comprising:
- a first amplitude calculator that calculates a first amplitude value from transmission quadrature base band signals;
- a limiting coefficient calculator that calculates an amplitude limiting coefficient with respect to said first amplitude value;
- first amplitude limiter that limits the amplitude of said transmission quadrature base band signals using said amplitude limiting coefficient;
- a quadrature modulator that modulates the amplitude-limited transmission quadrature base band signals to output radio frequency signals;
- and
- an amplifier that amplifies said radio frequency signals.
Dependencies are inferred from the claim text.