Pilot signals for synchronization and/or channel estimation
View Patent ↗The frame words of the preferred embodiment are especially suitable for frame synchronization and/or channel estimation. By adding the autocorrelation and cross-correlation functions of frame words, double maximum values equal in magnitude and opposite polarity at zero and middle shifts are obtained. This property can be used to slot-by-slot, double-check frame synchronization timing, single frame synchronization and/or channel estimation and allows reduction of the synchronization search time. Further, the present invention allows a simpler construction of a correlator circuit for a receiver. A frame synchronization apparatus and method using an optimal pilot pattern is used in a wide band code division multiple Access (W-CDMA) next generation mobile communication system. This method includes the steps of storing column sequences demodulated and inputted by slots, in a frame unit, in detecting frame synchronization for upward and downward link channels; converting the stored column sequences according to a pattern characteristic related to each sequence by using the pattern characteristic obtained from the relation between the column sequences; adding the converted column sequences by slots; and performing a correlation process of the added result to a previously designated code column.
1. A method for an apparatus receiving a pilot pattern, comprising:
storing pilot pattern sequences demodulated and/or inputted by slots of a frame for at least one of channel estimation or frame synchronization for at least one of uplink channel or downlink channel, wherein the pilot pattern sequences have a relation based on one or both of the following;
∑
i
=
1
α
R
i
(
τ
)
=
{
α
·
15
,
τ
=
0
-
α
,
τ
≠
0
,
α
=
1
,
2
,
3
,
…
,
8
(
1
)
where ∝=1, 2, 3, . . . , 8 and R i (τ) is representative of a first correlation function of the each pilot pattern sequence;
∑
i
=
1
α
/
2
(
R
2
i
-
1
,
2
i
(
τ
)
+
R
2
i
,
2
i
-
1
(
τ
+
1
)
)
=
{
-
α
·
15
,
τ
=
7
α
,
τ
≠
7
,
α
=
2
,
4
,
6
,
8
(
2
)
where ∝=2, 4, 6, 8 and R 2i−1, 2i (τ) and R 2i, 2i−1 are representative of a second correlation function between a pair of pilot pattern sequences, and i≧1.
2. An apparatus receiving a pilot pattern comprising:
a memory mapping and/or addressing block for storing pilot pattern sequences inputted and/or demodulated by slots, wherein the pilot pattern sequences have a relation based on one or both of the following:
∑
i
=
1
α
R
i
(
τ
)
=
{
α
·
15
,
τ
=
0
-
α
,
τ
≠
0
,
α
=
1
,
2
,
3
,
…
,
8
(
1
)
where ∝=1, 2, 3, . . . , 8 and R i (τ) is representative of a first correlation function of the each pilot pattern sequence and i≧1
∑
i
=
1
α
/
2
(
R
2
i
-
1
,
2
i
(
τ
)
+
R
2
i
,
2
i
-
1
(
τ
+
1
)
)
=
{
-
α
·
15
,
τ
=
7
α
,
τ
≠
7
,
α
=
2
,
4
,
6
,
8
(
2
)
where ∝=2, 4, 6, 8 and R 2i−1, 2i (τ) and R 2i, 2i−1 are representative of a second correlation function between a pair of pilot pattern sequences and i≧1.
3. The method of claim 1 , wherein 2≦i≦8.
4. The apparatus of claim 2 , wherein 2≦i≦8.
5. The method of claim 1 , further comprising converting the stored column sequences according to a pattern characteristic related to each sequence by using the pattern characteristic obtained from the relation between the column sequences;
adding the converted column sequences by slots; and
performing a correlation process of the added result to a previously designed code column.
6. The apparatus of claim 2 , wherein the implementing means comprises:
an adder for adding the converted outputs from the memory mapping/addressing block; and
a correlator for performing a correlation process of the added result to a previously designated code column.
7. The method of claim 1 , wherein the first correlation function is an auto-correlation function and the second correlation function is a cross-correlation function.
8. The apparatus of claim 2 , wherein the first correlation function is an auto-correlation function and the second correlation function is a cross-correlation function.
9. A method for an apparatus receiving a pilot pattern, comprising:
storing pilot pattern sequences demodulated and/or inputted by slots of a frame for at least one of channel estimation or frame synchronization for at least one of uplink or downlink channels, wherein the pilot pattern sequences have a relation based on one or both of the following;
R
i
(
τ
)
=
{
15
,
τ
=
0
-
1
,
τ
≠
0
,
i
=
1
,
2
,
…
,
8
(
1
)
where R i (τ) is the auto-correlation function of the pilot pattern sequence,
R
i
,
j
(
τ
)
=
{
-
15
,
τ
=
7
1
,
τ
≠
7
R
j
,
i
(
τ
+
1
)
=
{
-
15
,
τ
=
7
1
,
τ
≠
7
(
2
)
where R i,j (τ) is a cross-correlation function between a pair of pilot pattern sequences and i, j=1, 2, 3, . . . , 8.
10. An apparatus receiving a pilot pattern comprising:
a memory mapping and/or addressing block for storing pilot pattern sequences inputted and/or demodulated by slots, wherein the pilot pattern sequences have a relation based on one or both of the following:
R
i
(
τ
)
=
{
15
,
τ
=
0
-
1
,
τ
≠
0
,
i
=
1
,
2
,
…
,
8
(
1
)
where R i (τ) is the auto-correlation function of the pilot pattern sequence,
R
i
,
j
(
τ
)
=
{
-
15
,
τ
=
7
1
,
τ
≠
7
R
j
,
i
(
τ
+
1
)
=
{
-
15
,
τ
=
7
1
,
τ
≠
7
(
2
)
where R i,j (τ) is a cross-correlation function between a pair of pilot pattern sequences and i, j=1, 2, 3, . . . , 8.