| 摘要 |
PROBLEM TO BE SOLVED: To provide with a simple constitution predistorter for OFDM (orthogonal frequency division multiplexing) capable of performing highly accurate nonlinear distortion compensation. SOLUTION: This predistorter 100 for the OFDM is constituted of a digital processing circuit, composed of a distortion generation circuit 17 for inputting transmission data transmitted by respective sub carriers and computing the third distortion of the respective sub carriers and the outside of a band based on the transmission data, a phase amplitude adjustment circuit 18 for adjusting and outputting the phase and amplitude of the computed third distortion of the respective sub carriers and the outside of the band, so as to offset the third distortion component of nonlinear distortion generated in an amplifier in the output of the amplifier, a delay circuit 16 for delaying and adjusting transmission data for the processing time of the distortion generation circuit 17 and the phase amplitude adjustment circuit 18 and a combining circuit 19 for combining the output of the delay circuit 16 and the output of the phase amplitude adjustment circuit 18 for the corresponding sub carriers with each other.
|
