RECEIVING METHOD FOR RECEIVING SIGNALS BY A PLURALITY OF ANTENNAS, AND A RECEIVING APPARATUS AND A RADIO APPARATUS USING THE SAME

• US 20080063012A1
• Filed: 09/12/2007
• Published: 03/13/2008
• Est. Priority Date: 09/12/2006
• Status: Active Grant

• Current Assignee: Hera Wireless S.A. (Fineur International S.A.)
• Original Assignee: Hera Wireless S.A. (Fineur International S.A.)
• Inventors: Nakao, Seigo, Otani, Yoshiyuki, Ito, Kiyoshige
• Granted Patent: US 8,213,541 B2
• Time in Patent Office: Days
• US Class Current: 370/500
• CPC Class Codes: H04B 7/084 Equal gain combining, only phase adjustments antenna beam scanning or forming by phase or amplitude control H01Q3/26, e.g. phased arrays
• CPC Class Codes: H04B 7/0845 per branch equalization, e.g. by an FIR-filter or RAKE receiver per antenna branch rake receivers as such H04B1/7115
• CPC Class Codes: H04L 2027/0061 remodulation
• CPC Class Codes: H04L 2027/0067 Phase error detectors
• CPC Class Codes: H04L 27/2613 Structure of the reference signals
• CPC Class Codes: H04L 27/2657 Carrier synchronisation
• CPC Class Codes: H04L 27/2675 Pilot or known symbols

Abstract

A weight vector computing unit derives amounts of phase rotation for a plurality of multicarrier signals, respectively, and rotates the phase of a weight vector. A combining unit weights respectively a plurality of multicarrier signals with the phase-rotated weight vector, combines weighting results, and determines a combined result. A receiving weight vector computing unit remodulates the determined result and derives a first phase difference between the plurality of multicarrier signals and a result of the remodulation. The receiving weight vector computing unit remodulates the values of pilot signals and derives a second phase difference between the plurality of multicarrier signals and a result of the remodulation. Further, the receiving weight vector derives phase rotation amounts based on the first phase difference and the second phase difference.

Claims

1. A receiving apparatus, comprising:

a receiver which receives a plurality of multicarrier signals corresponding respectively to a plurality of antennas wherein a pilot signal is assigned to at least one subcarrier in the multicarrier signals;

a derivation unit which derives amounts of phase rotation for the plurality of multicarrier signals received in said receiver, respectively;

a rotation unit which rotates the phase of weight vectors to be multiplied by the plurality of multicarrier signals received in said receiver, by the amounts of phase rotation derived in said derivation unit; and

a combining unit which weights respectively the plurality of multicarrier signals received in said receiver, with the weight vectors rotated by said rotation unit and which combines results of weighting,

wherein said combining unit determines the combined results,

said derivation unit including;

means for executing remodulation based on the results determined by said combining unit and a channel characteristic and deriving a first phase difference between the plurality of multicarrier signals received in said receiver and a result of the remodulation;

means for executing remodulation based on a value of the pilot signal and the channel characteristic and deriving a second phase difference between the plurality of multicarrier signals received in said receiver and a result of the remodulation; and

means for deriving an amount of phase rotation based on the first phase difference and the second phase difference.

2. A receiving apparatus according to claim 1, wherein the multicarrier signal received by said receiver is formed of a plurality of streams,

wherein said derivation unit derives a common phase rotation amount over the streams,

wherein the weight vectors to be rotated in said rotation unit correspond respectively to the plurality of streams,

wherein said combining unit performs weighting, combining and decision on the plurality of streams, respectively.

3. A receiving apparatus according to claim 1, wherein said derivation unit derives the first phase difference by associating respectively with the plurality of subcarriers, and derives the second phase difference by expanding a phase difference in a subcarrier to which the pilot signal is assigned, to the plurality of subcarriers.

4. A receiving apparatus according to claim 1, wherein said derivation unit derives the phase rotation amount, based on the second phase difference derived in a predetermined symbol and the first phase difference derived in a symbol before the symbol from which the second phase difference has been derived.

5. A radio apparatus, comprising:

a plurality of antennas

a receiver which receives a plurality of multicarrier signals corresponding respectively to a plurality of antennas wherein a pilot signal is assigned to at least one subcarrier in the multicarrier signals;

a derivation unit which derives amounts of phase rotation for the plurality of multicarrier signals received in said receiver, respectively;

a rotation unit which rotates the phase of weight vectors to be multiplied by the plurality of multicarrier signals received in said receiver, by the amounts of phase rotation derived in said derivation unit; and

a combining unit which weights respectively the plurality of multicarrier signals received in said receiver, with the weight vectors rotated by said rotation unit and which combines results of weighting,

wherein said combining unit determines the combined results,

said derivation unit including;

means for executing remodulation based on the results determined by said combining unit and a channel characteristic and deriving a first phase difference between the plurality of multicarrier signals received in said receiver and a result of the remodulation;

means for executing remodulation based on a value of the pilot signal and the channel characteristic and deriving a second phase difference between the plurality of multicarrier signals received in said receiver and a result of the remodulation; and

means for deriving an amount of phase rotation based on the first phase difference and the second phase difference.

6. A receiving method, comprising:

receiving a plurality of multicarrier signals corresponding respectively to a plurality of antennas wherein a pilot signal is assigned to at least one subcarrier in the multicarrier signals;

deriving amounts of phase rotation for the received plurality of multicarrier signals, respectively;

rotating the phase of weight vectors to be multiplied by the received plurality of multicarrier signals, by the amounts of phase rotation derived in said deriving; and

weighting respectively the received plurality of multicarrier signals with the weight vectors rotated by said rotating and combining results of weighting,

wherein said combining determines the combined results,

said deriving including;

executing remodulation based on the determined results and a channel characteristic and deriving a first phase difference between the received plurality of multicarrier and a result of the remodulation;

executing remodulation based on a value of the pilot signal and the channel characteristic and deriving a second phase difference between the received plurality of multicarrier signals and a result of the remodulation; and

deriving an amount of phase rotation based on the first phase difference and the second phase difference.

7. A receiving apparatus, comprising:

a receiver which receives a plurality of multicarrier signals corresponding respectively to a plurality of antennas wherein a pilot signal is contained in a predetermined subcarrier in the multicarrier signals;

a derivation unit which derives, per antenna, amounts of phase rotation for the plurality of multicarrier signals, by using the pilot signal contained in the multicarrier signals received in said receiver;

a rotation unit which rotates the phase of weight vectors per subcarrier according to the phase rotation amounts, by associating the phase rotation amounts derived by said derivation unit per antenna with the weight vectors which are to be multiplied per subcarrier by the multicarrier signals received in said receiver, the weight vectors being formed by components corresponding respectively to the plurality of antennas; and

a combining unit which weights per antenna and per subcarrier the plurality of multicarrier signals received in said receiver, with the weight vectors rotated by said rotation unit per subcarrier and which combines results of weighting per subcarrier,

wherein the pilot signal contained in the multicarrier signals received in said receiver is formed by repeating a predetermined pattern, and

wherein said derivation unit derives per antenna the phase rotation amounts by use of the repeated pattern.

8. A receiving apparatus according to claim 7, wherein the multicarrier signal received in said receiver is formed by a plurality of streams,

wherein the weight vector which is to be phase-rotated in said rotation unit per subcarrier is formed by components corresponding respectively to the plurality of streams,

wherein said combining unit performs the weighting per antenna, per subcarrier and per stream and performs the combining per subcarrier and per stream, and

wherein said derivation unit derives phase rotation amounts for the multicarrier signals per antenna, regardless of the number of streams.

10. A receiving apparatus according to claim 7, said derivation unit including:

means for classifying one of the rotation amounts per antenna as a reference amount and classifying the remaining rotation amounts as amounts to be processed; and

means for outputting error between the amount to be processed and the reference amount as a per-antenna phase rotation amount,

wherein said rotation unit rotates the phase of an antenna which has been classified, as the amount to be processed, by said derivation unit.

9. A receiving apparatus, comprising:

a receiver which receives a plurality of multicarrier signals, formed by a plurality of streams, corresponding respectively to a plurality of antennas wherein a pilot signal is contained in a predetermined subcarrier in the multicarrier signals;

a derivation unit which derives, per antenna, amounts of phase rotation for the plurality of multicarrier signals, by using the pilot signal contained in the multicarrier signals received in said receiver;

a rotation unit which rotates the phase of the multicarrier signals according to the phase rotation amounts, by associating the phase rotation amounts derived by said derivation unit per antenna with the multicarrier signals received in said receiver; and

a combining unit which weights per antenna, per subcarrier and per stream the multicarrier signals which have been phase-rotated by said rotation unit, with a weight vector per subcarrier formed by components corresponding respectively to the plurality of antennas and the plurality of streams and which combines results of weighting per subcarrier and per stream,

wherein the pilot signal contained in the multicarrier signals received in said receiver is formed by repeating a predetermined pattern, and

wherein regardless of the number of streams said derivation unit derives per antenna the phase rotation amounts by use of the repeated patterns.

11. A radio apparatus, comprising:

a plurality of antennas;

a receiver which receives a plurality of multicarrier signals, which contain a pilot signal in a predetermined subcarrier, corresponding respectively to the plurality of antennas;

a derivation unit which derives, per antenna, amounts of phase rotation for the plurality of multicarrier signals, by using the pilot signal contained in the multicarrier signals received in said receiver;

a rotation unit which rotates the phase of a weight vector per subcarrier according to the phase rotation amounts, by associating the phase rotation amounts derived by said derivation unit per antenna with a per-subcarrier weight vector which is to be multiplied by the multicarrier signals received in said receiver and which is formed by components corresponding respectively to the plurality of antennas; and

a combining unit which weights per antenna and per subcarrier the multicarrier signals received in said receiver with the weight vector which has been phase-rotated by said rotation unit per subcarrier and which combines results of weighting per subcarrier,

wherein the pilot signal contained in the multicarrier signals received in said receiver is formed by repeating a predetermined pattern, and

wherein said derivation unit derives per antenna the phase rotation amounts by use of the repeated patterns.

12. A receiving method, comprising:

receiving a plurality of multicarrier signals, which contain a pilot signal in a predetermined subcarrier, corresponding respectively to a plurality of antennas;

deriving, per antenna, amounts of phase rotation for the plurality of multicarrier signals, by using the pilot signal contained in the received multicarrier signals;

rotating the phase of a weight vector per subcarrier according to the phase rotation amounts, by associating the phase rotation amounts derived per antenna with a per-subcarrier weight vector which is to be multiplied by the received multicarrier signals and which is formed by components corresponding respectively to the plurality of antennas; and

weighting per antenna and per subcarrier the received multicarrier signals with the weight vector which has been phase-rotated per subcarrier and combining results of weighting per subcarrier,

wherein the pilot signal contained in the multicarrier signals received in said receiving is formed by repeating a predetermined pattern, and

wherein said deriving derives per antenna the phase rotation amounts by use of the repeated patterns.

13. A receiving method, comprising:

receiving a plurality of multicarrier signals, formed by a plurality of streams, corresponding respectively to a plurality of antennas wherein a pilot signal is contained in a predetermined subcarrier in the multicarrier signals;

deriving, per antenna, amounts of phase rotation for the plurality of multicarrier signals, by using the pilot signal contained in the received multicarrier signals received;

rotating the phase of the multicarrier signals according to the phase rotation amounts, by associating the phase rotation amounts derived per antenna with the multicarrier signals received in said receiver; and

weighting per antenna, per subcarrier and per stream the multicarrier signals which have been phase-rotated in said rotating, with a weight vector per subcarrier formed by components corresponding respectively to the plurality of antennas and the plurality of streams and combining results of weighting per subcarrier and per stream,

wherein the pilot signal contained in the multicarrier signals received in said receiving is formed by repeating a predetermined pattern, and

wherein regardless of the number of streams said deriving derives per antenna the phase rotation amounts by use of the repeated patterns.

14. A receiving apparatus, comprising:

a receiver which receives signals corresponding respectively to a plurality of antennas;

a derivation unit which derives, per antenna, amounts of phase rotation for the signals received in said receiver;

a rotation unit which rotates the phase of a weight vector according to the phase rotation amounts by associating, per antenna, the phase rotation amounts derived by said derivation unit per antenna with a per-subcarrier weight vector which is to be multiplied by the signals received in said receiver and which is formed by components corresponding respectively to the plurality of antennas; and

a combining unit which weights per antenna the signals received in said receiver with the weight vector which has been phase-rotated by said rotation unit and which combines results of weighting,

wherein said combining unit determines a combined result, and

wherein said derivation unit executes remodulation per antenna based on the result determined by said combining unit and a channel characteristic per antenna, and derives per antenna the phase rotation amount by deriving per antenna a phase difference between the signals received in said receiver and a result of the remodulation.

18. A receiving apparatus according to claim 14, said derivation unit including:

means for classifying one of the rotation amounts per antenna as a reference amount and classifying the remaining rotation amounts as amounts to be processed; and

means for outputting error between the amount to be processed and the reference amount as a per-antenna phase rotation amount,

wherein said rotation unit rotates the phase of an antenna which has been classified, as the amount to be processed, by said derivation unit.

15. A receiving apparatus, comprising:

a receiver which receives multicarrier signals corresponding respectively to a plurality of antennas;

a derivation unit which derives, per antenna, amounts of phase rotation for the multicarrier signals received in said receiver;

a rotation unit which rotates the phase of a weight vector per subcarrier according to the phase rotation amounts by associating, per antenna, the phase rotation amounts derived by said derivation unit per antenna with a per-subcarrier weight vector which is to be multiplied by the multicarrier signals received in said receiver and which is formed by components corresponding respectively to the plurality of antennas; and

a combining unit which weights per antenna and per subcarrier the multicarrier signals received in said receiver with the weight vector which has been phase-rotated by said rotation unit per subcarrier and which combines results of weighting per subcarrier,

wherein said combining unit determines a combined result per subcarrier, and

wherein said derivation unit executes remodulation per antenna by associating, per subcarrier, the result determined per subcarrier by said combining unit and a channel characteristic per antenna and per subcarrier, and derives per antenna the phase rotation amount by deriving per antenna a phase difference between the multicarrier signals received in said receiver and a result of the remodulation.

16. A receiving apparatus according to claim 15, wherein the multicarrier signal received in said receiver is formed by a plurality of streams,

wherein the weight vector which is to be phase-rotated in said rotation unit per subcarrier is formed by components corresponding respectively to the plurality of streams,

wherein said combining unit performs the weighting per antenna, per subcarrier and per stream and makes a decision per subcarrier and per stream, and

wherein said derivation unit executes remodulation according to the number of streams, and derives the phase rotation amounts for the multicarrier signals per antenna, regardless of the number of streams.

17. A receiving apparatus, comprising:

a receiver which receives signals corresponding respectively to a plurality of antennas;

a derivation unit which derives, per antenna, amounts of phase rotation for the signals received in said receiver;

a rotation unit which rotates the phase of the signals according to the phase rotation amounts by associating, per antenna, the phase rotation amounts derived by said derivation unit per antenna with the signals received in said receiver; and

a combining unit which weights per antenna the signals which have been phase-rotate by said rotation unit with a weight vector formed by components corresponding respectively to the plurality of antennas and which combines results of weighting,

wherein said combining unit determines a combined result, and

wherein said derivation unit executes remodulation per antenna based on the result determined by said combining unit and a channel characteristic per antenna, and derives per antenna the phase rotation amount by deriving per antenna a phase difference between the signals received in said receiver and a result of the remodulation.

19. A radio apparatus, comprising:

a plurality of antennas;

a receiver which receives signals corresponding respectively to the plurality of antennas;

a derivation unit which derives, per antenna, amounts of phase rotation for the signals received in said receiver;

a rotation unit which rotates the phase of a weight vector per subcarrier according to the phase rotation amounts by associating, per antenna, the phase rotation amounts derived by said derivation unit per antenna with a weight vector which is to be multiplied by the signals received in said receiver and which is formed by components corresponding respectively to the plurality of antennas; and

a combining unit which weights per antenna the signals received in said receiver with the weight vector which has been phase-rotated by said rotation unit and which combines results of weighting,

wherein said combining unit determines a combined result, and

wherein said derivation unit executes remodulation per antenna based on the result determined by said combining unit and a channel characteristic per antenna, and derives per antenna the phase rotation amount by deriving per antenna a phase difference between the signals received in said receiver and a result of the remodulation.

20. A receiving method, comprising:

receiving signals corresponding respectively to a plurality of antennas;

deriving, per antenna, amounts of phase rotation for the received signals;

rotating the phase of a weight vector per subcarrier according to the phase rotation amounts by associating, per antenna, the phase rotation amounts derived per antenna with a weight vector which is to be multiplied by the received signals and which is formed by components corresponding respectively to the plurality of antennas; and

weighting per antenna the received signals with the weight vector which has been phase-rotated in said rotating and combining results of weighting,

wherein said combining determines a combined result, and

wherein said deriving executes remodulation per antenna based on the determined result and a channel characteristic per antenna, and derives per antenna the phase rotation amount by deriving per antenna a phase difference between the received signals received and a result of the remodulation.