Method, apparatus and system for random access
A method can be used for facilitating a random access procedure between a first transceiver and a second transceiver within a cell. The first transceiver selects a signature sequence from a set of signature sequences, incorporates the signature sequence into a signal, and transmits the signal to the second transceiver. The set of signature sequences being obtained from a Zadoff-Chu sequence with zero correlation zone.
1. A method of facilitating a random access procedure between a first transceiver and a second transceiver within a cell, the method comprising:
selecting, by the first transceiver, a signature sequence from a set of signature sequences, wherein the set of signature sequences is obtained from a Zadoff-Chu sequence with zero correlation zone, the Zadoff-Chu sequence being:
a
(
k
)
=
{
W
N
k
2
/
2
+
qk
,
N
even
W
N
k
(
k
+
1
)
/
2
+
qk
,
N
odd
,
k
=
0
,
1
,
…
,
N
-
1
,
where W N =exp(−j2π/N), r, q and N are integers, r is relatively prime to N and value of r is indicated by the second transceiver to the first transceiver for generation of the set of signature sequences;
incorporating, by the first transceiver, the signature sequence into a signal; and
transmitting, by the first transceiver, the signal to the second transceiver.
2. The method of claim 1 , wherein the zero correlation zone of the signature sequence selected is associated with a size of the cell.
3. The method of claim 1 , wherein the signature sequence selected is incorporated into a preamble portion of the signal.
4. The method of claim 3 , wherein the preamble portion of the signal comprises a cyclic prefix.
5. The method of claim 1 , wherein the signature sequence selected is randomly selected from the set of signature sequences.
6. The method of claim 1 , wherein the set of signature sequences allows for a low power back-off for the first transceiver.
7. The method of claim 1 , wherein q=0, and N is an odd integer.
8. The method of claim 1 , wherein r=1.
9. The method of claim 1 , wherein the set of signature sequences is specific to the cell.
10. An apparatus operable in a cell of a wireless communications system, the apparatus comprising a processor coupled to a memory, wherein the processor is programmed to operate in the communications system by:
selecting a signature sequence from a set of signature sequences, wherein the set of signature sequences is obtained from a Zadoff-Chu sequence with zero correlation zone, the Zadoff-Chu sequence being:
a
(
k
)
=
{
W
N
k
2
/
2
+
qk
,
N
even
W
N
k
(
k
+
1
)
/
2
+
qk
,
N
odd
,
k
=
0
,
1
,
…
,
N
-
1
,
where W N =exp(−j2πr/N), r, q and N are integers, r is relatively prime to N and value of r is indicated by a second transceiver to the apparatus for generation of the set of signature sequences;
incorporating the signature sequence into a signal; and
transmitting the signal to a transceiver.
11. The apparatus of claim 10 , wherein the zero correlation zone of the signature sequence selected is associated with a size of the cell.
12. The apparatus of claim 10 , wherein the signature sequence selected is incorporated into a preamble portion of the signal.
13. The apparatus of claim 12 , wherein the preamble portion of the signal comprises a cyclic prefix.
14. The apparatus of claim 10 , wherein the signature sequence selected is randomly selected from the set of signature sequences.
15. The apparatus of claim 10 , wherein the set of signature sequences allows for a low power back-off for the apparatus.
16. The apparatus of claim 10 , wherein q=0, and N is an odd integer.
17. The apparatus of claim 10 , wherein r=1.
18. The apparatus of claim 10 , wherein the set of signature sequences is specific to the cell.
19. A wireless communications system, comprising:
a first transceiver; and
a second transceiver;
wherein the first transceiver is configured to:
select a signature sequence from a set of signature sequences, wherein the set of signature sequences being obtained from a Zadoff-Chu sequence with zero correlation zone, the Zadoff-Chu sequence being:
a
(
k
)
=
{
W
N
k
2
/
2
+
qk
,
N
even
W
N
k
(
k
+
1
)
/
2
+
qk
,
N
odd
,
k
=
0
,
1
,
…
,
N
-
1
,
where W N =exp(−j2πr/N), r, q and N are integers, r is relatively prime to N and value of r is indicated by the second transceiver to the first transceiver for generation of the set of signature sequences;
incorporate the signature sequence into a signal; and
transmit the signal to the second transceiver; and
wherein the second transceiver is configured to receive the transmitted signal.