Integrated circuit for controlling selection of random access preamble sequence
View Patent ↗A sequence allocating method and apparatus wherein in a system where a plurality of different Zadoff-Chu sequences or GCL sequences are allocated to a single cell, the arithmetic amount and circuit scale of a correlating circuit at a receiving end can be reduced. In ST 201, a counter (a) and a number (p) of current sequence allocations are initialized, and in ST 202, it is determined whether the number (p) of current sequence allocations is coincident with a number (K) of allocations to one cell. In ST 203, it is determined whether the number (K) of allocations to the one cell is odd or even. If K is even, in ST 204 -ST 206, sequence numbers (r=a and r=N−a), which are not currently allocated, are combined and then allocated. If K is odd, in ST 207 -ST 212, for sequences that cannot be paired, one of sequence numbers (r=a and r=N−a), which are not currently allocated, is allocated.
1. A terminal apparatus comprising:
a receiver, which, in operation, receives an index that is associated with a sequence number a and a sequence number N−a, wherein a is an integer, and N is a sequence length; and
circuitry, which, in operation, generates a random access preamble from a sequence with the sequence number a or a sequence with the sequence number N−a based on the received index; and
a transmitter, which, in operation, transmits the random access preamble.
2. The terminal apparatus according to claim 1 , wherein the circuitry, in operation, selects one of sequences generated based on at least one of the sequence number a and the sequence number N−a, and generates the random access preamble from the selected sequence.
3. The terminal apparatus according to claim 1 , wherein the receiver, in operation, receives the index, which is broadcasted from a base station.
4. The terminal apparatus according to claim 1 , wherein the sequence c r (k) is defined by
c
r
(
k
)
=
exp
{
-
j
2
π
r
N
(
k
(
k
+
1
)
2
+
qk
)
}
where q is an integer, r is a sequence number, and k is 0 to N−1.
5. The terminal apparatus according to claim 1 , wherein the sequence with the sequence number a and the sequence with the sequence number N−a are conjugate to each other.
6. A communication method comprising:
receiving an index that is associated with a sequence number a and a sequence number N−a, wherein a is an integer, and N is a sequence length; and
generating a random access preamble from a sequence with the sequence number a or a sequence with the sequence number N−a based on the received index; and
transmitting the random access preamble.
7. The communication method according to claim 6 , wherein the generating includes: selecting one of sequences generated based on at least one of the sequence number a and the sequence number N−a; and generating the random access preamble from the selected sequence.
8. The communication method according to claim 6 , wherein the receiving includes receiving the index, which is broadcasted from a base station.
9. The communication method according to claim 6 , wherein the sequence c r (k) is defined by
c
r
(
k
)
=
exp
{
-
j
2
π
r
N
(
k
(
k
+
1
)
2
+
qk
)
}
where q is an integer, r is a sequence number, and k is 0 to N−1.
10. The communication method according to claim 6 , wherein the sequence with the sequence number a and the sequence with the sequence number N−a are conjugate to each other.