Reception apparatus, reception method, reception program, and reception system

1. A reception apparatus comprising:

spectrum inversion detection means for detecting the occurrence or absence of spectrum inversion in a received signal complying with the Digital Video Broadcasting-Terrestrial 2 standard known as DVB-T2, using a P 1 signal constituting said received signal;

spectrum inversion means for performing a spectrum inversion process on said received signal if the occurrence of said spectrum inversion is detected at least by said spectrum inversion detection means; and

demodulation means for demodulating said received signal having undergone said spectrum inversion process if the occurrence of said spectrum inversion is detected by said spectrum inversion detection means, said demodulation means further demodulating said received signal yet to undergo said spectrum inversion process if the absence of said spectrum inversion is detected by said spectrum inversion detection means,

wherein said spectrum inversion means always performs said spectrum inversion process on said received signal regardless of whether the occurrence or the absence of said spectrum inversion is detected.

2. The reception apparatus according to claim 1 , further comprising:

correlation means for obtaining a correlation value between said received signal and a signal acquired by shifting the frequency of said received signal by a frequency difference between a real information part constituting said P 1 signal and an overlay part overlaid with said real information part, on the assumption that said spectrum inversion has not occurred in said received signal; and

inverse correlation means for obtaining a correlation value between said received signal and a signal acquired by shifting the frequency of said received signal by said frequency difference on the assumption that said spectrum inversion has occurred in said received signal,

wherein, if said received signal is said P 1 signal, then said spectrum inversion detection means detects the occurrence or absence of said spectrum inversion based on a result of comparing a maximum absolute value of said correlation value acquired by said correlation means, with a maximum absolute value of said correlation value obtained by said inverse correlation means.

3. The reception apparatus according to claim 2 , further comprising

P 1 detection means for detecting that said received signal is said P 1 signal if the larger of the two absolute correlation values obtained by said correlation means and said inverse correlation means is a maximum value,

wherein said spectrum inversion detection means detects the occurrence or absence of said spectrum inversion if said P 1 detection means detects that said received signal is said P 1 signal.

4. The reception apparatus according to claim 3 , wherein:

said demodulation means includes FFT computation means for performing FFT computation on said received signal having undergone said spectrum inversion process if said spectrum inversion detection means detects the occurrence of said spectrum inversion at a timing at which said P 1 detection means detects that said received signal is said P 1 signal, said FFT computation means further performing FFT computation on said received signal yet to undergo said spectrum inversion process if said spectrum inversion detection means detects the absence of said spectrum inversion at the same timing; and

said FFT computation means resets said FFT computation every time said P 1 detection means detects that said received signal is said P 1 signal.

5. The reception apparatus according to claim 1 , further comprising:

correlation means for obtaining a correlation value between said received signal and a signal acquired by shifting the frequency of said received signal by a frequency difference between a real information part constituting said P 1 signal and an overlay part overlaid with said real information part, on the assumption that said spectrum inversion has not occurred in said received signal, said correlation means further obtaining a correlation value between said received signal and a signal acquired by shifting the frequency of said received signal by said frequency difference on the assumption that said spectrum inversion has occurred in said received signal; and

P 1 detection means for detecting that said received signal is said P 1 signal if the absolute value of said correlation value obtained by said correlation means is a maximum value,

wherein, if said P 1 detection means detects that said received signal is said P 1 signal and if said correlation value is obtained by said correlation means on the assumption that said spectrum inversion has not occurred in said received signal, then said spectrum inversion detection means detects the absence of said spectrum inversion, said spectrum inversion detection means further detecting the occurrence of said spectrum inversion if said correlation value is obtained by said correlation means on the assumption that said spectrum inversion has occurred in said received signal.

6. The reception apparatus according to claim 5 , wherein:

said demodulation means includes FFT computation means for performing FFT computation on said received signal having undergone said spectrum inversion process if said spectrum inversion detection means detects the occurrence of said spectrum inversion at a timing at which said P 1 detection means detects that said received signal is said P 1 signal, said FFT computation means further performing FFT computation on said received signal yet to undergo said spectrum inversion process if said spectrum inversion detection means detects the absence of said spectrum inversion at the same timing; and

said FFT computation means resets said FFT computation every time said P 1 detection means detects that said received signal is said P 1 signal.

7. A reception method for use with a reception apparatus receiving a received signal complying with the Digital Video Broadcasting-Terrestrial 2 standard known as DVB-T2, said reception method comprising the steps of:

detecting the occurrence or absence of spectrum inversion in said received signal using a P 1 signal constituting said received signal;

performing a spectrum inversion process on said received signal if the occurrence of said spectrum inversion is detected at least in the spectrum inversion detecting step;

demodulating said received signal having undergone said spectrum inversion process if the occurrence of said spectrum inversion is detected in said spectrum inversion detecting step; and

demodulating said received signal yet to undergo said spectrum inversion process if the absence of said spectrum inversion is detected in said spectrum inversion detecting step,

wherein said spectrum inversion process is always performed on said received signal regardless of whether the occurrence or the absence of said spectrum inversion is detected.

8. A non-transitory computer-readable storage medium having computer readable program codes for controlling reception of a received signal complying with the Digital Video Broadcasting-Terrestrial 2 standard known as DVB-T2, embodied in the computer readable storage medium, the computer readable program codes, when executed cause a computer to execute a process comprising the steps of:

detecting the occurrence or absence of spectrum inversion in said received signal using a P 1 signal constituting said received signal;

performing a spectrum inversion process on said received signal if the occurrence of said spectrum inversion is detected at least in the spectrum inversion detecting step;

demodulating said received signal having undergone said spectrum inversion process if the occurrence of said spectrum inversion is detected in said spectrum inversion detecting step; and

demodulating said received signal yet to undergo said spectrum inversion process if the absence of said spectrum inversion is detected in said spectrum inversion detecting step,

wherein said spectrum inversion process is always performed on said received signal regardless of whether the occurrence or the absence of said spectrum inversion is detected.

9. A reception system comprising:

acquisition means for acquiring over a transmission channel a signal complying with the Digital Video Broadcasting-Terrestrial 2 standard known as DVB-T2, as a received signal; and

transmission channel decoding process means for performing a transmission channel decoding process on said received signal acquired by said acquisition means,

wherein said transmission channel decoding process means includes

spectrum inversion detection means for detecting the occurrence or absence of spectrum inversion in said received signal using a P 1 signal constituting said received signal,

spectrum inversion means for performing a spectrum inversion process on said received signal if the occurrence of said spectrum inversion is detected at least by said spectrum inversion detection means, and

demodulation means for demodulating said received signal having undergone said spectrum inversion process if the occurrence of said spectrum inversion is detected by said spectrum inversion detection means, said demodulation means further demodulating said received signal yet to undergo said spectrum inversion process if the absence of said spectrum inversion is detected by said spectrum inversion detection means.

10. A reception system comprising:

transmission channel decoding process means for performing a transmission channel decoding process on a received signal which is acquired over a transmission channel and which complies with the Digital Video Broadcasting-Terrestrial 2 standard known as DVB-T2; and

information source decoding process means for performing an information source decoding process on said received signal having undergone said transmission channel decoding process performed by said transmission channel decoding process means,

wherein said transmission channel decoding process means includes

spectrum inversion detection means for detecting the occurrence or absence of spectrum inversion in said received signal using a P 1 signal constituting said received signal,

spectrum inversion means for performing a spectrum inversion process on said received signal if the occurrence of said spectrum inversion is detected at least by said spectrum inversion detection means, and

demodulation means for demodulating said received signal having undergone said spectrum inversion process if the occurrence of said spectrum inversion is detected by said spectrum inversion detection means, said demodulation means further demodulating said received signal yet to undergo said spectrum inversion process if the absence of said spectrum inversion is detected by said spectrum inversion detection means.

11. A reception system comprising:

transmission channel decoding process means for performing a transmission channel decoding process on a received signal which is acquired over a transmission channel and which complies with the Digital Video Broadcasting-Terrestrial 2 standard known as DVB-T2; and

output means for outputting an image or a sound based on said received signal having undergone said transmission channel decoding process performed by said transmission channel decoding process means,

wherein said transmission channel decoding process means includes

spectrum inversion detection means for detecting the occurrence or absence of spectrum inversion in said received signal using a P 1 signal constituting said received signal,

spectrum inversion means for performing a spectrum inversion process on said received signal if the occurrence of said spectrum inversion is detected at least by said spectrum inversion detection means, and

demodulation means for demodulating said received signal having undergone said spectrum inversion process if the occurrence of said spectrum inversion is detected by said spectrum inversion detection means, said demodulation means further demodulating said received signal yet to undergo said spectrum inversion process if the absence of said spectrum inversion is detected by said spectrum inversion detection means.

12. A reception system comprising:

transmission channel decoding process means for performing a transmission channel decoding process on a received signal which is acquired over a transmission channel and which complies with the Digital Video Broadcasting-Terrestrial 2 standard known as DVB-T2; and

recording control means for controlling the recording of said received signal having undergone said transmission channel decoding process performed by said transmission channel decoding process means,

wherein said transmission channel decoding process means includes

spectrum inversion detection means for detecting the occurrence or absence of spectrum inversion in said received signal using a P 1 signal constituting said received signal,

spectrum inversion means for performing a spectrum inversion process on said received signal if the occurrence of said spectrum inversion is detected at least by said spectrum inversion detection means, and

demodulation means for demodulating said received signal having undergone said spectrum inversion process if the occurrence of said spectrum inversion is detected by said spectrum inversion detection means, said demodulation means further demodulating said received signal yet to undergo said spectrum inversion process if the absence of said spectrum inversion is detected by said spectrum inversion detection means.

13. A reception apparatus comprising:

a spectrum inversion detection section configured to detect the occurrence or absence of spectrum inversion in a received signal complying with the Digital Video Broadcasting-Terrestrial 2 standard known as DVB-T2, using a P 1 signal constituting said received signal;

a spectrum inversion section configured to perform a spectrum inversion process on said received signal if the occurrence of said spectrum inversion is detected at least by said spectrum inversion detection section; and

a demodulation section configured to demodulate said received signal having undergone said spectrum inversion process if the occurrence of said spectrum inversion is detected by said spectrum inversion detection section, said demodulation section further demodulating said received signal yet to undergo said spectrum inversion process if the absence of said spectrum inversion is detected by said spectrum inversion detection section

wherein said spectrum inversion section always performs said spectrum inversion process on said received signal regardless of whether the occurrence or the absence of said spectrum inversion is detected.

14. A reception system comprising:

an acquisition section configured to acquire over a transmission channel a signal complying with the Digital Video Broadcasting-Terrestrial 2 standard known as DVB-T2, as a received signal; and

a transmission channel decoding process section configured to perform a transmission channel decoding process on said received signal acquired by said acquisition section,

wherein said transmission channel decoding process section includes

a spectrum inversion detection section configured to detect the occurrence or absence of spectrum inversion in said received signal using a P 1 signal constituting said received signal,

a spectrum inversion section configured to perform a spectrum inversion process on said received signal if the occurrence of said spectrum inversion is detected at least by said spectrum inversion detection section, and

a demodulation section configured to demodulate said received signal having undergone said spectrum inversion process if the occurrence of said spectrum inversion is detected by said spectrum inversion detection section, said demodulation section further demodulating said received signal yet to undergo said spectrum inversion process if the absence of said spectrum inversion is detected by said spectrum inversion detection section.

15. A reception system comprising:

a transmission channel decoding process section configured to perform a transmission channel decoding process on a received signal which is acquired over a transmission channel and which complies with the Digital Video Broadcasting-Terrestrial 2 standard known as DVB-T2; and

an information source decoding process section configured to perform an information source decoding process on said received signal having undergone said transmission channel decoding process performed by said transmission channel decoding process section,

wherein said transmission channel decoding process section includes

a spectrum inversion detection section configured to detect the occurrence or absence of spectrum inversion in said received signal using a P 1 signal constituting said received signal,

a spectrum inversion section configured to perform a spectrum inversion process on said received signal if the occurrence of said spectrum inversion is detected at least by said spectrum inversion detection section, and

a demodulation section configured to demodulate said received signal having undergone said spectrum inversion process if the occurrence of said spectrum inversion is detected by said spectrum inversion detection section, said demodulation section further demodulating said received signal yet to undergo said spectrum inversion process if the absence of said spectrum inversion is detected by said spectrum inversion detection section.

16. A reception system comprising:

a transmission channel decoding process section configured to perform a transmission channel decoding process on a received signal which is acquired over a transmission channel and which complies with the Digital Video Broadcasting-Terrestrial 2 standard known as DVB-T2; and

an output section configured to output an image or a sound based on said received signal having undergone said transmission channel decoding process performed by said transmission channel decoding process section,

wherein said transmission channel decoding process section includes

a spectrum inversion detection section configured to detect the occurrence or absence of spectrum inversion in said received signal using a P 1 signal constituting said received signal,

a spectrum inversion section configured to perform a spectrum inversion process on said received signal if the occurrence of said spectrum inversion is detected at least by said spectrum inversion detection section, and

a demodulation section configured to demodulate said received signal having undergone said spectrum inversion process if the occurrence of said spectrum inversion is detected by said spectrum inversion detection section, said demodulation section further demodulating said received signal yet to undergo said spectrum inversion process if the absence of said spectrum inversion is detected by said spectrum inversion detection section.

17. A reception system comprising:

a transmission channel decoding process section configured to perform a transmission channel decoding process on a received signal which is acquired over a transmission channel and which complies with the Digital Video Broadcasting-Terrestrial 2 standard known as DVB-T2; and

a recording control section configured to control the recording of said received signal having undergone said transmission channel decoding process performed by said transmission channel decoding process section,

wherein said transmission channel decoding process section includes

a spectrum inversion detection section configured to detect the occurrence or absence of spectrum inversion in said received signal using a P 1 signal constituting said received signal,

a spectrum inversion section configured to perform a spectrum inversion process on said received signal if the occurrence of said spectrum inversion is

detected at least by said spectrum inversion detection section, and a demodulation section configured to demodulate said received signal having undergone said spectrum inversion process if the occurrence of said spectrum inversion is detected by said spectrum inversion detection section, said demodulation section further demodulating said received signal yet to undergo said spectrum inversion process if the absence of said spectrum inversion is detected by said spectrum inversion detection section.

18. A reception apparatus comprising:

spectrum inversion detection means for detecting the occurrence or absence of spectrum inversion in a received signal complying with the Digital Video Broadcasting-Terrestrial 2 standard known as DVB-T2, using a P 1 signal constituting said received signal;

spectrum inversion means for performing a spectrum inversion process on said received signal if the occurrence of said spectrum inversion is detected at least by said spectrum inversion detection means;

demodulation means for demodulating said received signal having undergone said spectrum inversion process if the occurrence of said spectrum inversion is detected by said spectrum inversion detection means, said demodulation means further demodulating said received signal yet to undergo said spectrum inversion process if the absence of said spectrum inversion is detected by said spectrum inversion detection means;

correlation means for obtaining a correlation value between said received signal and a signal acquired by shifting the frequency of said received signal by a frequency difference between a real information part constituting said P 1 signal and an overlay part overlaid with said real information part, on the assumption that said spectrum inversion has not occurred in said received signal; and

inverse correlation means for obtaining a correlation value between said received signal and a signal acquired by shifting the frequency of said received signal by said frequency difference on the assumption that said spectrum inversion has occurred in said received signal,

wherein, if said received signal is said P 1 signal, then said spectrum inversion detection means detects the occurrence or absence of said spectrum inversion based on a result of comparing a maximum absolute value of said correlation value acquired by said correlation means, with a maximum absolute value of said correlation value obtained by said inverse correlation means.