Method of determining an acquisition indicator bit in a communication system
View Patent ↗A method of determining an acquisition indicator bit AI s at a receiver in a communication system which includes receiving multiplexed acquisition indicator bits y=B×AI+n, where B is the signature matrix known at both base station and UE, AI is all the acquisition indicator bits and n represents noise. Next, an estimated value of the acquisition indicator bit AÎ MMSE (s) as a function of ∑ j B T ( s , j ) × y ( j ) is calculated, where B T (s,.) is the s-th row vector of the transposed matrix B T for acquisition indicator bit AI s . Finally, the acquisition indicator bit AI s is set as follows: AI s =−1, if AÎ MMSE ( s )< R AI s =0, if R≦AÎ MMSE ( s )< U AI s =1, if AÎ MMSE ( s )≧ U, where R and U are decision thresholds.
1. A method of determining an acquisition indicator bit AI s at a receiver in a communication system, the method comprising:
receiving multiplexed acquisition bits y=B×AI+n, where B is the signature matrix known at both base station and the receiver, AI is all the acquisition indicator bits and n represents noise;
calculating an estimated value of the AI bit of interest AÎ MMSE (s) as a function of
∑
j
B
T
(
s
,
j
)
×
y
(
j
)
,
where B T (s,.) is the s-th row vector of the transposed matrix B T for acquisition indicator bit AI s ; and
setting the acquisition indicator bit AI s as follows:
AI s =−1, if AÎ MMSE ( s )< R
AI s =0, if R≦AÎ MMSE ( s )< U
AI s =1, if AÎ MMSE ( s )≧ U
where R and U are decision thresholds,
wherein the estimated value AÎ MMSE (S) is calculated by
A
I
^
MMSE
(
s
)
=
1
(
J
+
σ
^
2
)
∑
0
J
-
1
B
T
(
s
,
j
)
×
y
(
j
)
,
wherein {circumflex over (σ)} 2 represents estimated noise variance at the receiver, and
J is an integer greater than or equal to 0.
2. The method according to claim 1 , wherein R and U are equal absolute values.
3. The method according to claim 1 , wherein R and U are −0.5 and 0.5, respectively.
4. The method according to claim 1 , wherein the estimated value AÎ MMSE (s) is calculated for J=32, thereby resulting in the equation:
A
I
^
MMSE
(
s
)
=
1
(
32
+
σ
^
2
)
∑
0
31
B
T
(
s
,
j
)
×
y
(
j
)
.
5. The method of any of claim 1 , wherein the method pre-stores a matrix B or B T .
6. The method of any of claim 1 , wherein the method is performed in software.