Method of detecting indicator information in wireless communication system
A method of detecting indicator information received by a receiver of a wireless communication system is provided, and the method includes determining a threshold value that reduces costs incurred by a false alarm rate that decides discontinuous transmission (DTX) information transmitted from a transmitter as non-DTX information and a missed detection rate that decides non-DTX information transmitted from the transmitter as DTX information; and detecting the indicator information using the threshold value. The threshold value is determined based on a reception quality level for acknowledgement (ACK) information when the transmitter transmits the ACK information.
1. A method of detecting indicator information received by a receiver of a wireless communication system, the method comprising:
determining a threshold value that reduces costs incurred by a false alarm rate that determines discontinuous transmission (DTX) information transmitted from a transmitter as non-DTX information and a missed detection rate that determines non-DTX information transmitted from the transmitter as DTX information; and
detecting the indicator information using the threshold value,
wherein the threshold value is determined based on a reception quality level for acknowledgement (ACK) information when the transmitter transmits the ACK information, and
wherein the threshold value is determined based on a signal power of the received indicator information, an inverse function of an error function, and the false alarm rate.
2. The method of claim 1 , wherein the threshold value is a threshold value ηfor received indicator information y, and is determined based on
η=√{square root over (2)}σ ·erf −1 (1−2P FA ),
wherein σ denotes a signal power of the received indicator information, erf−1 denotes an inverse function of an error function, and PFA denotes false a alarm rate.
3. The method of claim 1 , wherein the costs include a call setup delay incurred by the false alarm rate and the missed detection rate.
4. The method of claim 1 , wherein the threshold value is a threshold value SNRth for a SNRy which is a signal to noise ratio of the received indicator information y.
5. The method of claim 4 , further comprising:
calculating the signal to noise ratio SNRy,
wherein detecting the indicator information using the threshold value comprises determining the indicator information by comparing the signal to noise ratio SNRy with the threshold value SNRth.
6. The method of claim 5 , wherein the threshold value SNRth is determined based on one of:
SNR
th
_
MinCost
=
2
(
ln
(
T
01
-
T
10
)
P
(
H
0
)
T
10
·
P
(
H
1
)
+
SNR
ACK
2
2
SNR
ACK
2
)
2
and
SNR
th
_
MinCost
=
2
(
ln
(
T
01
-
T
10
)
T
10
+
SNR
ACK
2
2
SNR
ACK
2
)
2
,
wherein T01 denotes a call setup delay incurred when a false alarm occurs, T10 denotes a call setup delay incurred when missed detection occurs, P(H0) denotes a probability that assumes indicator information is DTX information, P(H1) denotes a probability that assumes indicator information is non-DTX information, and SNRACK denotes a reception quality level for ACK information.
7. The method of claim 1 , wherein determining the threshold value that reduces the costs incurred by the false alarm rate and missed detection rate comprises one of:
calculating a threshold value that reduces the costs to be the threshold value; and
selecting at least one threshold value from a table storing threshold values for reducing the costs to be the threshold value.
8. The method of claim 1 , wherein the reception quality level is SNRACK and is calculated using information received from a higher layer or is calculated from a progression of indicator information that is received in advance and is determined to be non-DTX information.
9. The method of claim 4 , wherein the signal to noise ratio SNRy is defined as y2/σ2 or y2.
10. The method of claim 1 , wherein the indicator information is binary information, and the non-DTX information includes ACK information, or wherein the indicator information is non-binary information, and the non-DTX information includes ACK information and Negative-Acknowledge (NACK) information.
11. An apparatus that detects indicator information in a wireless communication system, the apparatus comprising:
a controller configured to determine a threshold value that reduces costs incurred by a false alarm rate that determines discontinuous transmission (DTX) information transmitted from a transmitter as non-DTX information and a missed detection rate that determines non-DTX information transmitted from the transmitter as DTX information; and
a detector configured to detect indicator information using the threshold value,
wherein the threshold value is determined based on a reception quality level for acknowledge (ACK) information when the transmitter transmits the ACK information, and
wherein the threshold value is determined based on a signal power of the received indicator information, an inverse function of an error function, and the false alarm rate.
12. The apparatus of claim 11 , wherein the threshold value is a threshold value η for received indicator information y, and is determined based on
η=√{square root over (2)}σ ·erf −1 (1−2 P FA ),
wherein σ denotes a signal power of the received indicator information, erf−1 denotes an inverse function of an error function, and PFA denotes a false alarm rate.
13. The apparatus of claim 11 , wherein the costs include a call setup delay incurred by the false alarm rate and the missed detection rate.
14. The apparatus of claim 11 , wherein the threshold value is a threshold value SNRth for a SNRy which is a signal to noise ratio of the received indicator information y.
15. The apparatus of claim 14 , further comprising:
a baseband signal processing unit configured to calculate the signal to noise ratio SNRy,
wherein the detector is further configured to determine the indicator information by comparing the signal to noise ratio SNRy with the threshold value SNRth.
16. The apparatus of claim 15 , wherein the controller is further configured to determine the threshold value SNRth that reduces the costs, based on one of:
SNR
th
_
MinCost
=
2
(
ln
(
T
01
-
T
10
)
P
(
H
0
)
T
10
·
P
(
H
1
)
+
SNR
ACK
2
2
SNR
ACK
2
)
2
and
SNR
th
_
MinCost
=
2
(
ln
(
T
01
-
T
10
)
T
10
+
SNR
ACK
2
2
SNR
ACK
2
)
2
,
wherein T01 denotes a call setup delay incurred when a false alarm occurs, T10 denotes a call setup delay incurred when missed detection occurs, P(H0) denotes a probability that assumes indicator information is DTX information, P(H1) denotes a probability that assumes indicator information is non-DTX information, and SNRACK denotes a reception quality level for ACK information.
17. The apparatus of claim 11 , wherein the controller is further configured to determine the threshold value by executing one of calculating a threshold value that reduces the costs to be the threshold value and selecting at least one threshold value from a table storing threshold values for reducing the costs to be the threshold value.
18. The apparatus of claim 11 , wherein the baseband signal processing unit is further configured to calculate a reception quality level SNRACK using information received from a higher layer or from a progression of indicator information that is received in advance and is determined to be non-DTX information.
19. The apparatus of claim 14 , wherein the signal to noise ratio SNRy is defined as y2/σ2 or y2.
20. The apparatus of claim 11 , wherein the indicator information is binary information, and the non-DTX information includes ACK information, or wherein the indicator information is non-binary information, and the non-DTX information includes ACK information and Negative-Acknowledge (NACK) information.