Radio communication device and radio communication method
When an Ack/Nack signal is transmitted from a user terminal to a base station in an upstream control channel by using an Ack/Nack resource, the signal is code-multiplexed by using a code sequence containing an orthogonal sequence and a cyclic-shifted sequence and transmitted from a plurality of user terminals to the base station. If an aggregation size indicating the number of control signals of the downstream control channel is greater than one, it is determined that no resource located at the right of the axis of the cyclic-shifted amount of the cyclic-shifted sequence in the same orthogonal code of the orthogonal sequence is used, and the Ack/Nack signal to which CDD is applied from a plurality of antennas is transmitted by using a resource ACK #0 allocated to the own device and an unused resource ACK #1, which have the same orthogonal code, but have different cyclic-shifted amounts.
1. A transmitting apparatus comprising:
a cyclically shifted sequence multiplying section configured to multiply a response signal with a cyclically shifted sequence defined by a cyclic shift value among a plurality of cyclic shift values;
a spreading section configured to spread the multiplied response signal with an orthogonal sequence among a plurality of orthogonal sequences, wherein the orthogonal sequence and the cyclic shift value are determined from a resource index, and the resource index is associated with a control channel element (CCE) number which indicates a number of a first CCE of one or more CCEs used to transmit a control signal in a downlink control channel; and
a transmitter that transmits the spread response signal using one or more antenna ports, wherein when a first antenna port and a second antenna port are used, said transmitter uses a first orthogonal sequence and a first cyclic shift value that are determined by a first resource index for the spread response signal transmitted using the first antenna port, and uses a second orthogonal sequence and a second cyclic shift value that are determined by a second resource index for the spread response signal transmitted using the second antenna port, the second resource index being a number which equals the first resource index plus one.
2. The transmitting apparatus according to claim 1 , wherein the cyclic shift value determined from the first resource index and the cyclic shift value determined from the second resource index are next to each other at a set interval.
3. The transmitting apparatus according to claim 1 , wherein the orthogonal sequence determined from the first resource index is same as the orthogonal sequence determined from the second resource index.
4. The transmitting apparatus according to claim 1 , wherein:
six cyclic shift values with #0, #2, #4, #6, #8 and #10 among twelve cyclic shift values, which are represented by consecutive numbers #0 to #11 in a direction in which a cyclic shift value is incremented by a set value, are associated with one of the plurality of orthogonal sequences; and
two cyclic shift values, numbers of which are different by two, among the six cyclic shift values are determined from the first resource index and the second resource index, respectively.
5. The transmitting apparatus according to claim 4 , wherein six cyclic shift values with #1, #3, #5, #7, #9 and #11 among the twelve cyclic shift values, are associated with another of the plurality of orthogonal sequences.
6. The transmitting apparatus according to claim 1 , further comprising:
a scrambling section configured to scramble the spread response signal according to the first or second resource index.
7. The transmitting apparatus according to claim 1 , further comprising:
a scrambling section configured to scramble the spread response signal depending on the cyclic shift value determined from the first or second resource index.
8. The transmitting apparatus according to claim 7 , further comprising:
a scrambling section configured to scramble the spread response signal such that a phase of a response signal, for which one of two cyclic shift values that are associated with one of the plurality of orthogonal sequences and that are next to each other at a set interval is used, is rotated by 90 degree with respect to a phase of the other spread response signal, for which the other of two cyclic shift values is used.
9. The transmitting apparatus according to claim 1 , further comprising:
a scrambling section configured to scramble the spread response signal such that a phase of a response signal, for which the first resource index is used, is same as a phase of another response signal, for which the second resource index is used.
10. A response signal transmitting method comprising:
multiplying a response signal with a cyclically shifted sequence defined by a cyclic shift value among a plurality of cyclic shift values;
spreading the multiplied response signal with an orthogonal sequence among a plurality of orthogonal sequences, wherein the orthogonal sequence and the cyclic shift value is determined from a resource index, and the resource index is associated with a control channel element (CCE) number which indicates a number of a first CCE of one or more CCEs used to transmit a control signal in a downlink control channel; and
transmitting the spread response signal using one or more antenna ports, wherein when a first antenna port and a second antenna port are used, a first orthogonal sequence and a first cyclic shift value that are determined by a first resource index are used for the spread response signal transmitted using the first antenna port, and a second orthogonal sequence and a second cyclic shift value that are determined by a second resource index are used for the spread response signal transmitted using the second antenna port, the second resource index being a number which equals the first resource index plus one.
11. The response signal transmitting method according to claim 10 , wherein the cyclic shift value determined from the first resource index and the cyclic shift value determined from the second resource index are next to each other at a set interval.
12. The response signal transmitting method according to claim 10 , wherein the orthogonal sequence determined from the first resource index is same as the orthogonal sequence determined from the second resource index.
13. The response signal transmitting method according to claim 10 , wherein:
six cyclic shift values with #0, #2, #4, #6, #8 and #10 among twelve cyclic shift values, which are represented by consecutive numbers #0 to #11 in a direction in which a cyclic shift value is incremented by a set value, are associated with one of the plurality of orthogonal sequences; and
two cyclic shift values, numbers of which are different by two, among the six cyclic shift values are determined from the first resource index and the second resource index, respectively.
14. The response signal transmitting method according to claim 13 , wherein six cyclic shift values with #1, #3, #5, #7, #9 and #11 among the twelve cyclic shift values, are associated with another of the plurality of orthogonal sequences.
15. The response signal transmitting method according to claim 10 , further comprising:
scrambling the spread response signal according to the first or second resource index.
16. The response signal transmitting method according to claim 10 , further comprising:
scrambling the spread response signal depending on the cyclic shift value determined from the first or second resource index.
17. The response signal transmitting method according to claim 16 , further comprising:
scrambling the spread response signal such that a phase of a response signal, for which one of two cyclic shift values that are associated with one of the plurality of orthogonal sequences and that are next to each other at a set interval is used, is rotated by 90 degree with respect to a phase of the other spread response signal, for which the other of two cyclic shift values is used.
18. The response signal transmitting method according to claim 10 , further comprising:
scrambling the spread response signal such that a phase of a response signal, for which the first resource index is used, is same as a phase of another response signal, for which the second resource index is used.