Data transmission and reception method and apparatus robust against phase noise for high efficiency satellite transmission
View Patent ↗A data transmission and reception apparatus is used for a high efficiency satellite transmission. The apparatus includes an initial phase calculation unit to calculate initial phase information using a preamble and a postamble of a data packet applied thereto, a symbol transition calculation unit to perform forward and backward metric operations using the initial phase information calculated by the initial phase calculation unit and a pilot symbol in the data packet to calculate a symbol transition of the data packet, and a phase error estimation unit to calculating a phase error using the pilot symbol in a spot where the pilot symbol is positioned, the calculated phase error being provided to the symbol transition calculation unit.
1. A data transmission and reception apparatus for a high efficiency satellite transmission, the apparatus comprising:
an initial phase calculation unit configured to calculate initial phase information using a preamble and a postamble of a data packet applied thereto;
a symbol transition calculation unit configured to perform forward and backward metric operations using the initial phase information calculated by the initial phase calculation unit and a pilot symbol in the data packet to calculate a symbol transition of the data packet; and
a phase error estimation unit configured to calculate a phase error using the pilot symbol existing in the data packet, the calculated phase error being provided to the symbol transition calculation unit.
2. The apparatus of claim 1 , wherein the initial phase information is phase information of a start point and an end point of the initial phase of the data packet.
3. The apparatus of claim 2 , wherein the initial phase calculation unit calculates phase information a f,0 of the start point of the initial phase is calculated using the equation below:
a
f
,
0
=
(
∑
k
=
0
L
pre
-
1
r
k
p
k
*
)
σ
AWGN
2
where r k r k is data information of the data packet, P k is pilot information, and σ 2 AWGN denotes noise information of a channel.
4. The apparatus of claim 2 , wherein the initial phase calculation unit calculates phase information a b,s of the end point of the initial phase by the equation below:
a
b
,
S
=
(
∑
k
=
0
L
pre
-
1
r
i
(
L
-
k
)
p
L
-
k
*
)
σ
AWGN
2
where r L−k is data information of the reception data packet, and P L−k is pilot information, and σ 2 AWGN denotes noise information of a channel.
5. The apparatus of claim 1 , wherein the symbol transition calculation unit calculates the symbol transition of the data packet by calculating new phase information of the data packet in forward and backward directions through forward and backward metric operations.
6. The apparatus of claim 5 , wherein the symbol transition calculation unit calculates new phase information a ′ k of the reception data packet in the forward direction by using the equation below:
α
k
′
=
α
k
-
1
+
2
r
k
-
1
c
_
k
-
1
*
2
σ
AWGN
2
,
α
k
=
α
k
′
1
+
σ
Δ
2
α
k
′
where k=1, . . . , P
where α k−1 is an initial phase, r k−1 is data information of the reception data packet, and c k−1 is codeword data.
7. The apparatus of claim 5 , wherein the symbol transition calculation unit calculates the new phase information β′ k of the reception data packet in the backward direction by using the equation below:
β
k
′
=
β
k
+
1
+
2
r
k
+
1
c
_
k
+
1
*
2
σ
AWGN
2
,
β
k
=
β
k
′
1
+
σ
Δ
2
β
k
′
where k=1, . . . , P
where β k+1 is an initial phase, r k+l is data information of the reception data packet, and c k+1 is codeword data.
8. A data transmission/reception method for a high efficiency satellite transmission, the method comprising:
calculating initial phase information using a preamble and a postamble of a data packet;
performing forward and backward metric operations using the initial phase information and a pilot symbol of the data packet; and
calculating a symbol transition of the data packet through the forward and backward metric operations.
9. The method of claim 8 , wherein said performing forward and backward metric operations comprises calculating a phase error using the pilot symbol existing in the data packet.
10. The method of claim 8 , wherein the initial phase information is phase information of a start point and an end point of the initial phase of the data packet.
11. The method of claim 10 , wherein the phase information a f,0 of the start point of the initial phase is calculated as follows:
a
f
,
0
=
(
∑
k
=
0
L
pre
-
1
r
k
p
k
*
)
σ
AWGN
2
where r k is data information of the reception data packet, p k is pilot information, and σ 2 AWGN denotes noise information of a channel.
12. The method of claim 10 , wherein the phase information a b,s of the end point of the initial phase is calculated as follows:
a
b
,
S
=
(
∑
k
=
0
L
pre
-
1
r
i
(
L
-
k
)
p
L
-
k
*
)
σ
AWGN
2
where r L−k is data information of the reception data packet, p L−k is pilot information, and σ 2 AWGN denotes noise information of a channel,
13. The method of claim 8 , wherein said calculating a symbol transition comprises calculating the symbol transition of the reception data packet by calculating new phase information of the reception data packet in forward and backward directions through forward and backward metric operations.
14. The method of claim 13 , wherein the new phase information α′ k of the reception data packet in the forward direction is calculated as follows:
α
k
′
=
α
k
-
1
+
2
r
k
-
1
c
_
k
-
1
*
2
σ
AWGN
2
,
α
k
=
α
k
′
1
+
σ
Δ
2
α
k
′
where k =1, . . . , P
where α k−1 is an initial phase, r k−1 is data information of the reception data packet, and c k−1 is codeword data.
15. The method of claim 13 , wherein the new phase information β′ k of the reception data packet in the backward direction is calculated by using the equation below:
β
k
′
=
β
k
+
1
+
2
r
k
+
1
c
_
k
+
1
*
2
σ
AWGN
2
,
β
k
=
β
k
′
1
+
σ
Δ
2
β
k
′
where k=1, . . . , p
where β k+1 is an initial phase, r k+1 is data information of the reception data packet, and c k+1 is codeword data.