Apparatus and method for full-diversity, full-rate space-time block coding for two transmit antennas
View Patent ↗An apparatus and method for full-diversity, full-rate space-time block coding in a transmitter using two Tx antennas are provided. An input symbol sequence is STBC-encoded in a predetermined method and transmitted through the two Tx antennas.
1. A transmitter comprising:
a space-time block coder for space-time encoding input information symbols by:
C
=
[
a
×
s
1
+
j
×
b
×
s
4
b
×
s
2
+
a
×
s
3
a
×
s
2
-
b
×
s
3
j
×
b
×
s
1
+
a
×
s
4
]
where C is a coding matrix, s 1 , s 2 , s 3 , s 4 are the input information symbols, and a and b are constants in the relationship a 2 +b 2 =½, and for outputting space-time coded symbols; and
two antennas for transmitting the space-time coded symbols.
2. The transmitter of claim 1 , wherein a and b are defined by:
a
=
Re
(
1
2
ⅇ
jθ
)
b
=
Im
(
1
2
ⅇ
jθ
)
where θ is a phase angle.
3. The transmitter of claim 2 , wherein the phase angle θ is calculated by:
arg
max
θ
mean
(
C
.
A
.
)
(where C.A. represents coding advantage (i.e. coding gain).
4. The transmitter of claim 2 , wherein the phase angle θ satisfies:
12°≦θ≦13° or 77°≦θ≦78° in the range of 0°≦θ≦90°.
5. A transmitter comprising:
a space-time block coder for space-time encoding input information symbols by:
C
=
[
a
×
s
1
+
j
×
b
×
s
4
b
×
s
2
+
a
×
s
3
a
×
s
2
-
b
×
s
3
j
×
b
×
s
1
+
a
×
s
4
]
where C is a coding matrix, s 1 , s 2 , s 3 , s 4 are the input information symbols, and a and b are defined as
a
=
Re
(
1
2
ⅇ
jθ
)
b
=
Im
(
1
2
ⅇ
jθ
)
where θ represents a phase angle satisfying the range: 12°+90n≦θ≦13°+90n or 77°+90n≦θ≦78°+90n (n is a positive integer) in the range of 90°<θ, and for outputting space-time coded symbols; and
two antennas for transmitting the space-time coded symbols.
6. A space-time block coder transmitting method in a transmitter including and having two transmit antennas, the method comprising: space-time encoding input information symbols by:
C
=
[
a
×
s
1
+
j
×
b
×
s
4
b
×
s
2
+
a
×
s
3
a
×
s
2
-
b
×
s
3
j
×
b
×
s
1
+
a
×
s
4
]
where C is a coding matrix, s 1 , s 2 , s 3 , s 4 are the input information symbols, and a and b are constants in the relationship a 2 +b 2 =½, and transmitting space-time coded symbols through the two transmit antennas.
7. The method of claim 6 , wherein a and b are defined by:
a
=
Re
(
1
2
ⅇ
jθ
)
b
=
Im
(
1
2
ⅇ
jθ
)
where θ is a phase.
8. The space-time block coder of claim 7 , wherein the phase angle θ is calculated by:
arg
max
θ
mean
(
C
.
A
.
)
where C.A. represents coding advantage (i.e. coding gain).
9. The space-time block coder of claim 7 , wherein the phase θ satisfies: 12°≦θ≦13° or 77°≦θ≦78° in the range of 0°≦θ≦90°, and 12°+90n≦θ≦13°+90n or 77°+90n≦θ≦78°+90n (n is a positive integer) in the range of 90°<θ.
10. A transmitting method in a transmitter having two transmit antennas, comprising the steps of:
space-time block coding input information symbols by:
C
=
[
a
×
s
1
+
j
×
b
×
s
4
b
×
s
2
+
a
×
s
3
a
×
s
2
-
b
×
s
3
j
×
b
×
s
1
+
a
×
s
4
]
where C is a coding matrix, s 1 , s 2 , s 3 , s 4 are the input information symbols, and a and b are constants in the relationship a 2 +b 2 =½, and outputting space-time coded symbols; and
transmitting the space-time coded symbols through the two transmit antennas.
11. The transmitting method of claim 10 , wherein a and b are defined by:
a
=
Re
(
1
2
ⅇ
jθ
)
b
=
Im
(
1
2
ⅇ
jθ
)
where θ is a phase angle.
12. The transmitting method of claim 11 , wherein the phase angle θ satisfies: 12°≦θ≦13° or 77°≦θ≦78° in the range of 0°≦θ≦90°.
13. A transmitting method in a space-time block coding transmitter having two transmit antennas, comprising the steps of:
space-time encoding input information symbols by:
C
=
[
a
×
s
1
+
j
×
b
×
s
4
b
×
s
2
+
a
×
s
3
a
×
s
2
-
b
×
s
3
j
×
b
×
s
1
+
a
×
s
4
]
where C is a coding matrix, s 1 , s 2 , s 3 , s 4 are the input information symbols, and a and b are defined as:
C
=
[
a
×
s
1
+
j
×
b
×
s
4
b
×
s
2
+
a
×
s
3
a
×
s
2
-
b
×
s
3
j
×
b
×
s
1
+
a
×
s
4
]
where θ representing a phase angle satisfies: 12°+90n≦θ≦13°+90n or 77°+90n≦θ≦78°+90n (n is a positive integer) in the range of 90°<θ); and
transmitting space-time coded symbols through the two transmit antennas.
14. A space-time block coding method in a transmitter having two transmit antennas, comprising the steps of:
space-time encoding input information symbols by:
C
=
[
a
×
s
1
+
j
×
b
×
s
4
b
×
s
2
+
a
×
s
3
a
×
s
2
-
b
×
s
3
j
×
b
×
s
1
+
a
×
s
4
]
where C is a coding matrix, s 1 , s 2 , s 3 , s 4 are the input information symbols, and a and b are constants in the relationship a 2 +b 2 =½; and
outputting space-time coded symbols.
15. The space-time block coding method of claim 14 , wherein a and b are defined by:
a
=
Re
(
1
2
ⅇ
jθ
)
b
=
Im
(
1
2
ⅇ
jθ
)
where θ is a phase angle.
16. The space-time block coding method of claim 15 , wherein the phase angle θ is calculated by:
arg
max
θ
mean
(
C
.
A
.
)
where C.A. represents coding advantage (i.e. coding gain).
17. The space-time block coding method of claim 15 , wherein the phase angle θ satisfies: 12°≦θ≦13° or 77°≦θ≦78° in the range of 0°≦θ≦90°, and 12°+90n≦θ≦13°+90n or 77°+90n≦θ≦78°+90n (n is a positive integer) in the range of 90°<θ.