Method of signal generation and signal generating device

Patent metadata

Field	Value
Publication number	US-10476720-B2
Application number	US-201916239145-A
Country	US
Kind code	B2
Filing date	Jan 3, 2019
Priority date	Feb 18, 2011
Publication date	Nov 12, 2019
Grant date	Nov 12, 2019

Abstract

A transmission method simultaneously transmitting a first modulated signal and a second modulated signal at a common frequency performs precoding on both signals using a fixed precoding matrix and regularly changes the phase of at least one of the signals, thereby improving received data signal quality for a reception device.

First claim

The invention claimed is:

1. A signal generation method comprising:
phase-changing all of a plurality of baseband signals using each of a plurality of phase changing patterns, each of the plurality of phase changing patterns being different from each other;
inverse-fast-Fourier-transforming each of the plurality of baseband signals to which the phase change is applied, to each of a plurality of orthogonal frequency-division multiplexing (OFDM) transmission signals; and
applying Gard Interval insertion processing to each of the plurality of OFDM transmission signals for transmission on a same frequency band and at a same time, wherein
the phase of each of the plurality of baseband signals is regularly changed according to each of the plurality of phase changing patterns for each subcarrier of the plurality of OFDM transmission signals,
each of the plurality of phase changing patterns having N phase change value candidates,
N being an integer greater than two, and
each candidate of the N phase change value candidates being selected at least once within a determined period.

2. A signal generation apparatus comprising:
phase change circuitry phase-changing all of a plurality of baseband signals using each of a plurality of phase changing patterns, each of the plurality of phase changing patterns being different from each other;
inverse fast Fourier transform circuitry inverse-fast-Fourier-transforming each of the plurality of baseband signals to which the phase change is applied, to each of a plurality of orthogonal frequency-division multiplexing (OFDM) transmission signals; and
Gard Interval insertion circuitry applying Gard Interval insertion processing to each of the plurality of OFDM transmission signals for transmission on a same frequency band and at a same time, wherein
the phase of each of the plurality of baseband signals is regularly changed according to each of the plurality of phase changing patterns for each subcarrier of the plurality of OFDM transmission signals,
each of the plurality of phase changing patterns having N phase change value candidates,
N being an integer greater than two, and
each candidate of the N phase change value candidates being selected at least once within a determined period.

3. A signal demodulation method for demodulating a reception signal obtained by receiving a plurality of orthogonal frequency-division multiplexing (OFDM) transmission signals, the signal demodulation method comprising:
obtaining the plurality of OFDM transmission signals, wherein
the plurality of OFDM transmission signals are generated by phase-changing all of a plurality of baseband signals using each of a plurality of phase changing patterns, inverse-fast-Fourier-transforming each of the plurality of baseband signals to which the phase change is applied, to each of the plurality of OFDM transmission signals;
applying Gard Interval insertion processing to each of the plurality of OFDM transmission signals for transmission on a same frequency band and at a same time, each of the plurality of phase changing patterns being different from each other, wherein
the phase of each of the plurality of baseband signals is regularly changed according to each of the plurality of phase changing patterns for each subcarrier of the plurality of OFDM transmission signals, each of the plurality of phase changing patterns having N phase change value candidates, N being an integer greater than two, and each candidate of the N phase change value candidates being selected at least once within a determined period; and
demodulating the reception signal from the plurality of OFDM transmission signals.

4. A signal demodulation apparatus for demodulating a reception signal obtained by receiving a plurality of orthogonal frequency-division multiplexing (OFDM) transmission signals, the signal demodulation apparatus comprising:
reception circuitry obtaining the plurality of OFDM transmission signals, wherein
the plurality of OFDM transmission signals are generated by phase-changing all of a plurality of baseband signals using each of a plurality of phase changing patterns, inverse-fast-Fourier-transforming each of the plurality of baseband signals to which the phase change is applied, to each of the plurality of OFDM transmission signals, and applying Gard Interval insertion processing to each of the plurality of OFDM transmission signals for transmission on a same frequency band and at a same time, each of the plurality of phase changing patterns being different from each other, and
the phase of each of the plurality of baseband signals is regularly changed according to each of the plurality of phase changing patterns for each subcarrier of the plurality of OFDM transmission signals, each of the plurality of phase changing patterns having N phase change value candidates, N being an integer greater than two, and
each candidate of the N phase change value candidates being selected at least once within a determined period; and
demodulate circuitry demodulating the reception signal from the plurality of OFDM transmission signals.

Assignees

• Sun Patent Trust

Inventors

• Murakami Yutaka
• Kimura Tomohiro
• Ouchi Mikihiro

Classifications

• H04B7/0842

  Weighted combining · CPC title

• H04B7/0697

  using spatial multiplexing · CPC title

• H04L5/0082

  at predetermined intervals · CPC title

• H04L1/0071

  Use of interleaving (interleaving per se H03M13/27) · CPC title

• H04L1/0048

  in conjunction with detection of multiuser or interfering signals, e.g. iteration between CDMA or MIMO detector and FEC decoder (for spatial equalizer H04L25/03286) · CPC title