Method and apparatus for transmitting or detecting a primary synchronization signal
A method and apparatus for transmitting or detecting primary synchronization signal. The receiver receives primary synchronization signal from a transmitter, and detects the sequence used in the received primary synchronization signal by using three root indexes. Here, the primary synchronization signal is generated by using a Zadoff-Chu sequence having one of the three root indexes. The three root indexes comprise a first index and a second index, and a sum of the first index and the second index corresponds to the length of the Zadoff-Chu sequence.
1. A method of detecting a sequence used in a primary synchronization signal by a receiver in a mobile communication system, the method comprising:
receiving the primary synchronization signal from a transmitter; and
detecting the sequence used in the received primary synchronization signal,
wherein the sequence used in the primary synchronization signal corresponds to a sequence having an even number length, the sequence being mapped on a frequency domain such that one half of the sequence is mapped before a DC frequency and the other half of the sequence is mapped after the DC frequency, and
wherein the sequence mapped on the frequency domain is generated by using Zadoff-Chu sequence having an odd number length.
2. The method of claim 1 ,
wherein the sequence mapped on the frequency domain from the Zadoff-Chu sequence is generated based on a following equation:
exp
(
-
ⅈ
M
π
n
(
n
+
1
)
N
)
,
and
wherein the odd number length of the Zadoff-Chu sequence is “N”, “M” is a root index of the Zadoff-Chu sequence, and “n” is an index of each of a plurality of constituent components of the generated sequence.
3. The method of claim 2 , wherein N is 63, and the even number length is 62.
4. The method of claim 3 ,
wherein a first 31 constituent components of the sequence that are mapped on the frequency domain are continuously mapped to a plurality of frequency resource elements corresponding to frequency resource element indices within a range of “−31” to “4,” and
wherein a last 31 constituent components of the sequence mapped on the frequency domain are continuously mapped to a plurality of frequency resource elements corresponding to frequency resource element indices within a range of “1” to “31”.
5. The method of claim 1 , wherein the sequence is detected by using 3 root indexes.
6. A receiver configured to detect a sequence used in a received (Rx) signal in a mobile communication system using orthogonal frequency division multiplexing (OFDM), the receiver comprising:
a radio frequency module configured to receive the Rx signal from a transmitter; and
a detector configured to detect the sequence used in the Rx signal,
wherein the sequence used in the Rx signal is generated in a frequency domain by using a Zadoff-Chu sequence having an index from a predetermined index set,
wherein the predetermined index set comprises a first index and a second index, and
wherein a sum of the first index and the second index corresponds to a length of the Zadoff-Chu sequence.
7. The receiver according to claim 6 ,
wherein the Zadoff-Chu sequence has an odd number length, and
wherein an equation for generating the sequence from the Zadoff-Chu sequence is based on the following equation:
exp
(
-
ⅈ
M
π
n
(
n
+
1
)
N
)
,
and
wherein the length of the Zadoff-Chu sequence is “N”, “M” is a root index of the Zadoff-Chu sequence, and “n” is index of each of constituent components of the generated sequence.
8. The receiver according to claim 7 , wherein “N” is 63, the first index is 34, and the second index is 29, respectively.
9. The receiver according to claim 6 , wherein the Rx signal is a P-SCH (Primary-SCH) signal.
10. The receiver according to claim 6 , wherein the receiver is configured to perform synchronization with a transmitter based on the sequence detection performed on the Rx signal.