INTERFERING SIGNAL CHARACTERIZING QUANTITY STORING METHOD AND DEVICE, INTERFERING SIGNAL CHARACTERIZING QUANTITY ACQUIRING METHOD AND DEVICE, AND INTERFERING SIGNAL SUPPRESSING METHOD AND DEVICE

• US 20090135972A1
• Filed: 10/23/2006
• Published: 05/28/2009
• Est. Priority Date: 10/24/2005
• Status: Active Grant

• Current Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: Hosokawa, Shuya, Miyanaga, Kenji, Urabe, Yoshio, Shirakata, Naganori, Mukai, Tsutomu, Tanaka, Koichiro, Imamura, Koji
• Granted Patent: US 8,023,599 B2
• Time in Patent Office: Days
• US Class Current: 375/346
• CPC Class Codes: H04B 1/1027 assessing signal quality or detecting noise/interference for the received signal
• CPC Class Codes: H04B 1/7107 Subtractive interference cancellation
• CPC Class Codes: H04B 17/336 Signal-to-interference ratio [SIR] or carrier-to-interference ratio [CIR]
• CPC Class Codes: H04L 2025/03414 Multicarrier
• CPC Class Codes: H04L 2025/03426 transmission using multiple-input and multiple-output channels

Abstract

An object is to identify interfering signals coming at random timings from different radio stations. In order to attain this object, a method for storing the characterizing quantity of an interfering signal included in a received signal comprises a characterizing quantity calculation step of calculating the characterizing quantity of the received signal; a received signal determination step of determining a probability that a desired signal is included in the received signal, and determining that the received signal is an interfering signal when determining that there is no probability that the desired signal is included in the received signal; and an interfering signal characterizing quantity storage step of storing the characterizing quantity of the received signal as an interfering signal characterizing quantity when it is determined at the received signal determination step that there is no probability that the desired signal is included in the received signal.

Claims

1. An interfering signal characterizing quantity storing method for storing a characterizing quantity of an interfering signal included in a received signal, said method comprising:

a characterizing quantity calculation step of calculating a characterizing quantity of the received signal;

a received signal determination step of determining a probability that a desired signal is included in the received signal, and determining that the received signal is an interfering signal when determining that there is no probability that the desired signal is included in the received signal; and

an interfering signal characterizing quantity storage step of storing the characterizing quantity of the received signal as an interfering signal characterizing quantity when it is determined at the received signal determination step that there is no probability that the desired signal is included in the received signal.

2. The interfering signal characterizing quantity storing method according to claim 1, further comprising:

a criterion value setting step of setting a criterion value which is a criterion for determining whether or not the interfering signal becomes a deterioration factor for a reception characteristic of the desired signal;

a comparison object value calculation step of calculating a comparison object value concerning the interfering signal, which is a comparison object for the criterion value, when it is detected that the interfering signal comes; and

a significant interfering signal determination step of determining whether or not the interfering signal is an interfering signal which becomes the deterioration factor for the reception characteristic of the desired signal based on the criterion value and the comparison object value when it is detected that the interfering signal comes,

wherein at the interfering signal characterizing quantity storage step, the characterizing quantity of the interfering signal is stored when it is determined at the significant interfering signal determination step that the interfering signal is the interfering signal which becomes the deterioration factor for the reception characteristic of the desired signal.

17. The interfering signal characterizing quantity storing method according to claim 2, wherein

an initial value of the criterion value is a received power value of a thermal noise which is a type of the interfering signal, and

the criterion value is updatable.

18. The interfering signal characterizing quantity storing method according to claim 2, wherein

the criterion value is a received power of the interfering signal which is previously received,

the comparison object value is a received power of the interfering signal which is currently received, and

at the significant interfering signal determination step, it is determined that the interfering signal which is currently received becomes the deterioration factor for the reception characteristic of the desired signal when the comparison object value is larger than the criterion value.

19. The interfering signal characterizing quantity storing method according to claim 2, wherein

the criterion value is a ratio (SIR) of a received power of the desired signal which is previously received to a received power of the interfering signal which is previously received, or a ratio (SIR) of a received power of the desired signal which is currently received to the received power of the interfering signal which is previously received,

the comparison object value is a ratio (SIR) of the received power of the desired signal which is previously received to a received power of the interfering signal which is currently received, or a ratio (SIR) of the received power of the desired signal which is currently received to the received power of the interfering signal which is currently received, and

at the significant interfering signal determination step, it is determined that the interfering signal which is currently received becomes the deterioration factor for the reception characteristic of the desired signal when the comparison object value is larger than the criterion value.

20. The interfering signal characterizing quantity storing method according to claim 2, wherein at the significant interfering signal determination step, the determination is performed based on a number of times of reception of the interfering signal within a certain period of time or based on a time period of reception of the interfering signal within a certain period of time.

3. An interfering signal characterizing quantity acquiring method for acquiring a characterizing quantity of an interfering signal included in a received signal, said method comprising:

a characterizing quantity calculation step of calculating a characterizing quantity of the received signal;

a received signal determination step of determining a probability that a desired signal is included in the received signal, and determining that the received signal is an interfering signal when determining that there is no probability that the desired signal is included in the received signal;

an interfering signal characterizing quantity storage step of storing the characterizing quantity of the received signal as an interfering signal characterizing quantity when it is determined at the received signal determination step that there is no probability that the desired signal is included in the received signal;

a similarity calculation step of calculating a similarity between the characterizing quantity of the received signal and the interfering signal characterizing quantity stored at the characterizing quantity storage step when it is determined at the received signal determination step that there is the probability that the desired signal is included in the received signal; and

an interfering signal characterizing quantity selection step of selecting an interfering signal characterizing quantity having the highest similarity from a plurality of the stored interfering signal characterizing quantities when there are interfering signal characterizing quantities having similarities, which are equal to or higher than a predetermined value, among the stored interfering signal characterizing quantities.

4. The interfering signal characterizing quantity acquiring method according to claim 3, wherein the characterizing quantity is a correlation value between signals which are concurrently received by a plurality of antennas.

5. The interfering signal characterizing quantity acquiring method according to claim 3, further comprising a step of dividing the received signal into a plurality of sub-bands,

wherein at the characterizing quantity calculation step, the characterizing quantity of the received signal is calculated for each sub-band.

6. The interfering signal characterizing quantity acquiring method according to claim 3, further comprising:

a first time interval measurement step of measuring a time interval from an end of the interfering signal to a time when another interfering signal comes;

a characterizing quantity association storage step of storing the characterizing quantity of the interfering signal and a characterizing quantity of said another interfering signal so as to be associated with each other for each first interfering station, which transmits the interfering signal, when the time interval is a predetermined interval;

a second time interval measurement step of measuring a time interval from the end of the interfering signal to the time when said another interfering signal comes when the desired signal comes during a time period when the characterizing quantity of the interfering signal is measured and the interfering signal ends during a time period when the desired signal comes;

a time interval determination step of determining whether or not the time interval measured at the second time interval measurement step corresponds to the predetermined period; and

a characterizing quantity selection step of collating a characterizing quantity of the interfering signal, which has been coming at a time when the desired signal comes, which characterizing quantity is measured before the desired signal comes, with information stored at the characterizing quantity storage step when determination of a correspondence is made at the time interval determination step, and selecting a characterizing quantity of said another interfering signal, which corresponds to the characterizing quantity of the interfering signal, from a plurality of the stored characterizing quantities of said another interfering signal.

7. The interfering signal characterizing quantity acquiring method according to claim 3, further comprising:

a first combined signal characterizing quantity measurement step of measuring a characterizing quantity of a combined signal of the interfering signal and the desired signal when it is detected that the desired signal comes during a time period when the characterizing quantity of the interfering signal is measured;

a characterizing quantity association storage step of storing the interfering signal characterizing quantity and the combined signal characterizing quantity so as to be associated with each other for each interfering station;

a second combined signal characterizing quantity measurement step of measuring a characterizing quantity of the combined signal of the desired signal and the interfering signal when it is detected that the interfering signal comes during a time period when the desired signal comes; and

an interfering signal characterizing quantity selection step of collating a value measured at the second combined signal characterizing quantity measurement step with information stored at the characterizing quantity association storage step, and selecting a characterizing quantity of an interfering signal of a corresponding interfering station from the stored interfering signal characterizing quantities of a plurality of interfering stations.

12. The interfering signal characterizing quantity acquiring method according to claim 5, wherein the similarity is a similarity which is calculated for a sub-band, among the plurality of sub-bands, which is outside of a frequency band of the desired signal.

13. The interfering signal characterizing quantity acquiring method according to claim 4, further comprising a phase component extraction step of extracting a phase component from the correlation value,

wherein at the similarity calculation step, a similarity concerning the phase component is calculated.

14. The interfering signal characterizing quantity acquiring method according to claim 4, further comprising a complex region determination step of determining in which region on a complex plane, which is divided into N regions (N is an integer number which is equal to or greater than 2), the correlation value, which is a complex number, exists,

wherein at the similarity calculation step, a similarity concerning a result of the region determination is calculated.

16. The interfering signal characterizing quantity acquiring method according to claim 6, wherein

the characterizing quantity association storage step includes a characterizing quantity comparison step of comparing the characterizing quantity of the interfering signal with the characterizing quantity of said another interfering signal,

the characterizing quantity comparison step includes a storage pattern in which when determining, based on a result of the comparison, that the characterizing quantity of the interfering signal and the characterizing quantity of said another interfering signal do not satisfy a predetermined condition concerning sameness, the first interfering station which transmits the interfering signal is considered to be different from a second interfering station which transmits said another interfering signal, and the characterizing quantity of the interfering signal and the characterizing quantity of said another interfering signal are stored so as to be associated with each other for each first interfering station, and

the characterizing quantity comparison step includes a storage pattern in which when determining, based on a result of the comparison, that the characterizing quantity of the interfering signal and the characterizing quantity of said another interfering signal satisfy the predetermined condition concerning sameness, the first interfering station which transmits the interfering signal is considered to be the same as the second interfering station which transmits said another interfering signal, the characterizing quantity of the interfering signal and the characterizing quantity of said another interfering signal are stored so as to be associated with each other for each first interfering station.

8. An interfering signal suppressing method for suppressing an interfering signal included in a received signal, said method comprising:

a characterizing quantity calculation step of calculating a characterizing quantity of the received signal;

a received signal determination step of determining a probability that a desired signal is included in the received signal, and determining that the received signal is an interfering signal when determining that there is no probability that the desired signal is included in the received signal;

an interfering signal characterizing quantity storage step of storing the characterizing quantity of the received signal as an interfering signal characterizing quantity when it is determined at the received signal determination step that there is no probability that the desired signal is included in the received signal;

a similarity calculation step of calculating a similarity between the characterizing quantity of the received signal and the interfering signal characterizing quantity stored at the characterizing quantity storage step when it is determined at the received signal determination step that there is the probability that the desired signal is included in the received signal;

an interfering signal characterizing quantity selection step of selecting an interfering signal characterizing quantity having the highest similarity from a plurality of the stored interfering signal characterizing quantities when there are interfering signal characterizing quantities having similarities, which are equal to or higher than a predetermined value, among the stored interfering signal characterizing quantities; and

an interfering signal suppression step of suppressing the interfering signal by using the selected interfering signal characterizing quantity.

15. The interfering signal suppressing method according to claim 8, further comprising:

a transmission path estimation step of performing transmission path estimation of the desired signal for each of the sub-bands; and

a weighting coefficients calculation step of calculating weighting coefficients from the selected interfering signal characterizing quantity and a transmission path estimation value of the desired signal,

wherein at the interfering signal suppression step, the interfering signal is suppressed by weighted combining a plurality of the received signals with the weighting coefficients.

9. An interfering signal characterizing quantity storing device for storing a characterizing quantity of an interfering signal included in a received signal, said device comprising:

a characterizing quantity calculation section for calculating a characterizing quantity of the received signal;

a received signal determination section for determining a probability that a desired signal is included in the received signal, and determining that the received signal is an interfering signal when determining that there is no probability that the desired signal is included in the received signal; and

an interfering signal characterizing quantity storage section for storing the characterizing quantity of the received signal as an interfering signal characterizing quantity when the received signal determination section determines that there is no probability that the desired signal is included in the received signal.

10. An interfering signal characterizing quantity acquiring device for acquiring a characterizing quantity of an interfering signal included in a received signal, said device comprising:

a characterizing quantity calculation section for calculating a characterizing quantity of the received signal;

a received signal determination section for determining a probability that a desired signal is included in the received signal, and determining that the received signal is an interfering signal when determining that there is no probability that the desired signal is included in the received signal;

an interfering signal characterizing quantity storage section for storing the characterizing quantity of the received signal as an interfering signal characterizing quantity when the received signal determination section determines that there is no probability that the desired signal is included in the received signal;

a similarity calculation section for calculating a similarity between the characterizing quantity of the received signal and the interfering signal characterizing quantity stored by the characterizing quantity storage section when the received signal determination section determines that there is the probability that the desired signal is included in the received signal; and

an interfering signal characterizing quantity selection section for selecting an interfering signal characterizing quantity having the highest similarity from a plurality of the stored interfering signal characterizing quantities when there are interfering signal characterizing quantities having similarities, which are equal to or higher than a predetermined value, among the stored interfering signal characterizing quantities.

11. An interfering signal suppressing device for suppressing an interfering signal included in the received signal, said device comprising:

a characterizing quantity calculation section for calculating a characterizing quantity of the received signal;

a received signal determination section for determining a probability that a desired signal is included in the received signal, and determining that the received signal is an interfering signal when determining that there is no probability that the desired signal is included in the received signal;

an interfering signal characterizing quantity storage section for storing the characterizing quantity of the received signal as an interfering signal characterizing quantity when the received signal determination section determines that there is no probability that the desired signal is included in the received signal;

a similarity calculation section for calculating a similarity between the characterizing quantity of the received signal and the interfering signal characterizing quantity stored by the characterizing quantity storage section when the received signal determination section determines that there is the probability that the desired signal is included in the received signal;

an interfering signal characterizing quantity selection section for selecting an interfering signal characterizing quantity having the highest similarity from a plurality of the stored interfering signal characterizing quantities when there are interfering signal characterizing quantities having similarities, which are equal to or higher than a predetermined value, among the stored interfering signal characterizing quantities; and

an interfering signal suppression section for suppressing the interfering signal by using the selected interfering signal characterizing quantity.