Terminal apparatus and sequence assigning method
Provided is a sequence allocation method capable of reducing inter-cell interference of a reference signal when a ZC sequence is used as the reference signal in a mobile communication system. In the sequence allocation method, R×M sequences specified by a ZC sequence number r (r=1 to R) and a cyclic shift sequence number m (m=1 to M) are divided into a plurality of sequence groups X (X=1 to R) in accordance with the transmission band width of the reference signal, so that the ZC sequence is allocated to each cell in each sequence group unit. When it is assumed that R=9 and M=6, the number of sequences is 54. Each of the sequence groups is formed by two sequences. Accordingly, the number of sequence groups is 27. The 27 types of sequence groups are allocated to each cell.
1. An integrated circuit comprising:
receiving circuitry, which, in operation, controls reception of control information related to a sequence in one of multiple groups, into which sequences for each of multiple sequence lengths having at least two different lengths are divided; and
transmitting circuitry, which, in operation, controls transmission of a reference signal, which is generated using the sequence in one of the multiple groups based on the control information,
wherein a first respective predefined number of sequence(s) contained in a first group of the multiple groups into which sequences having a first sequence length are divided is less than a second respective predefined number of sequences contained in a second group of the multiple groups into which sequences having a second sequence length are divided where the first sequence length is less than a threshold value and the second sequence length is greater than or equal to the threshold value.
2. The integrated circuit according to claim 1 , comprising:
at least one input coupled to the receiving circuitry, wherein the at least one input, in operation, inputs data; and
at least one output coupled to the transmitting circuitry, wherein the at least one output, in operation, outputs data.
3. The integrated circuit according to claim 1 , wherein each of the multiple groups contains a respective predefined number of sequence(s), and each respective predefined number depends on the sequence lengths.
4. The integrated circuit according to claim 1 , wherein each of the multiple groups contains a respective predefined number of sequence(s), and each respective predefined number varies depending on the sequence lengths.
5. The integrated circuit according to claim 1 , wherein the control information identifies the sequence in one of the multiple groups.
6. The integrated circuit according to claim 1 , wherein the control information identifies one of the multiple groups.
7. The integrated circuit according to claim 1 , wherein the reference signal has one of at least two different lengths.
8. The integrated circuit according to claim 1 , wherein the sequences for one sequence length of the reference signal are divided into the multiple groups.
9. The integrated circuit according to claim 1 , wherein each of the multiple groups for one sequence length contains the same number of the sequence(s).
10. The integrated circuit according to claim 1 , wherein one of the multiple groups is assigned to a terminal depending on a cell.
11. The integrated circuit according to claim 1 , wherein the sequence is a Zadoff-Chu sequence.
12. The integrated circuit according to claim 1 , wherein the sequences include multiple cyclically shifted sequences derived from a sequence through different cyclic shift values.
13. The integrated circuit according to claim 1 , wherein the sequences for each sequence length are divided into a number of the multiple groups, and the number is constant regardless of the sequence length.
14. The integrated circuit according to claim 2 , wherein the at least one output and the at least one input, in operation, are coupled to an antenna.
15. An integrated circuit comprising:
circuitry, which, in operation:
controls reception of control information related to a sequence in one of multiple groups, into which sequences for each of multiple sequence lengths having at least two different lengths are divided; and
controls transmission of a reference signal, which is generated using the sequence in one of the multiple groups based on the control information; and
at least one input coupled to the circuitry, wherein the at least one input, in operation, inputs data,
wherein a first respective predefined number of sequence(s) contained in a first group of the multiple groups into which sequences having a first sequence length are divided is less than a second respective predefined number of sequences contained in a second group of the multiple groups into which sequences having a second sequence length are divided where the first sequence length is less than a threshold value and the second sequence length is greater than or equal to the threshold value.
16. The integrated circuit according to claim 15 , comprising:
at least one output coupled to the circuitry, wherein the at least one output, in operation, outputs data.
17. The integrated circuit according to claim 15 , wherein each of the multiple groups contains a respective predefined number of sequence(s), and each respective predefined number depends on the sequence lengths.
18. The integrated circuit according to claim 15 , wherein each of the multiple groups contains a respective predefined number of sequence(s), and each respective predefined number varies depending on the sequence lengths.
19. The integrated circuit according to claim 15 , wherein the control information identifies the sequence in one of the multiple groups.
20. The integrated circuit according to claim 15 , wherein the control information identifies one of the multiple groups.
21. The integrated circuit according to claim 15 , wherein the reference signal has one of at least two different lengths.
22. The integrated circuit according to claim 15 , wherein the sequences for one sequence length of the reference signal are divided into the multiple groups.
23. The integrated circuit according to claim 15 , wherein each of the multiple groups for one sequence length contains the same number of the sequence(s).
24. The integrated circuit according to claim 15 , wherein one of the multiple groups is assigned to a terminal depending on a cell.
25. The integrated circuit according to claim 15 , wherein the sequence is a Zadoff-Chu sequence.
26. The integrated circuit according to claim 15 , wherein the sequences include multiple cyclically shifted sequences derived from a sequence through different cyclic shift values.
27. The integrated circuit according to claim 15 , wherein the sequences for each sequence length are divided into a number of the multiple groups, and the number is constant regardless of the sequence length.
28. The integrated circuit according to claim 16 , wherein the at least one output and the at least one input, in operation, are coupled to an antenna.