US 7,889,814 B2 · Transmitting and receiving apparatus for supporting transmit antenna diversity using space-time block code

Abstract

A transmitter and a receiver are disclosed herein that support transmit antenna diversity using space-time block coding in a wireless communication system. The transmitter produces symbol combinations containing, as their elements, input symbols, the inversions and conjugates of the symbols, and symbols obtained by rotating the phases of the symbols once, forms a matrix having symbols in at least two columns orthogonal to each other with the symbol combinations, and transmits the matrix. The receiver detects symbols that minimize maximum likelihood (ML) decoding metrics over all possible symbols using channel gains from transmit antennas to a receive antenna. Also, the receiver selects candidate symbols among all possible symbols according to the characteristics of transmitted modulation symbols and detects symbols that minimize the ML decoding metrics.

Claims12

Dependent claims

A receiver for receiving modulation symbols whose phases are rotated once from a transmitter in a wireless communication system, comprising:

first and second decoders for detecting symbol pairs that minimize maximum likelihood (ML) decoding metrics over all possible symbol pairs using signals received by a receive antenna from three transmit antennas for four time periods and channel gains from the transmit antennas to the receive antenna,
wherein if the modulation symbols are BPSK (Binary Phase Shift Keying) symbols, the first decoder computes parameters
R
1
=
⁢
α
*
⁢
r
1
+
β
⁢
1
2
⁢
r
2
*
+
γ
⁢
⁢
r
3
*
+
j
⁢
⁢
β
*
⁢
1
2
⁢
r
4
R
3
=
⁢
γ
⁢
⁢
r
2
*
-
j
⁢
⁢
β
*
⁢
1
2
⁢
r
1
+
α
*
⁢
r
4
-
β
*
⁢
1
2
⁢
r
3
*
R
13
=
⁢
j
⁡
(
C
1
+
C
3
)
2
C
1
=
⁢
-
α
*
⁢
β
⁢
2
-
αβ
*
⁢
2
C
3
=
⁢
j
⁢
⁢
γ
*
⁢
β
⁢
2
-
j
⁢
⁢
γβ
*
⁢
2
and the second decoder computes parameters
R
2
=
⁢
β
*
⁢
1
2
⁢
r
1
-
α
⁢
⁢
r
2
*
+
j
⁢
⁢
β
⁢
1
2
⁢
r
3
*
+
γ
*
⁢
r
4
R
4
=
⁢
γ
*
⁢
r
1
-
j
⁢
⁢
β
⁢
1
2
⁢
r
2
*
-
α
⁢
⁢
r
3
*
-
β
*
⁢
1
2
⁢
r
4
R
24
=
⁢
j
⁡
(
C
2
+
C
4
)
2
C
2
=
⁢
αβ
*
⁢
2
+
α
*
⁢
β
⁢
2
C
4
=
⁢
j
⁢
⁢
γβ
*
⁢
2
-
j
⁢
⁢
γ
*
⁢
β
⁢
2
where α, β and γ are the channel gains and r1, r2, r3 and r4 are the received signals, and R and C are variables,
and the first decoder finds a symbol pair (x1, x3) that minimizes |R1−x1|2+|R3−x3|2+|R13−x1*x3|2, and the second decoder finds a symbol (x2, x4) that minimizes |R2−x2|2+|R4−x4|2+|R24−x2*x4|2.

252 more elements

A receiver for receiving PSK (Phase Shift Keying) modulation symbols whose phases are rotated once from a transmitter in a wireless communication system, comprising:

first and second decoders for selecting candidate symbol pairs among all possible symbol pairs using signals received by a receive antenna from three transmit antennas for four time periods and channel gains from the transmit antennas to the receive antenna, and detecting symbol pairs that minimize maximum likelihood (ML) decoding metrics over the candidate symbol pairs,
wherein the first decoder computes
R
1
=
α
*
⁢
r
1
+
β
⁢
1
2
⁢
r
2
*
+
γ
⁢
⁢
r
3
*
-
ν
*
⁢
β
*
⁢
1
2
⁢
r
4
R
3
=
νγ
⁢
⁢
r
2
*
+
β
*
⁢
1
2
⁢
r
1
+
α
*
⁢
r
4
-
β
⁢
1
2
⁢
r
3
*
R
13
=
-
(
C
1
+
C
3
)
2
C
1
⁢
=
-
α
*
⁢
βν
⁢
2
+
αβ
*
⁢
2
C
3
=
γβ
*
⁢
ν
⁢
2
-
γ
*
⁢
β
⁢
2
where α, β and γ are the channel gains, r1, r2, r3 and r4 are the received signals, and v is a predetermined phase value by which the transmitter rotates the phases of the symbols, and R and C are variables,
outputs a symbol pair (x1, x3) if x1*x3=x13, x1 being the closest symbol to R13, x3 being the closest symbol to R3, and x13 being the closest symbol to R13, and if x1*x3≠x13, computes an angle Φd by dividing the angle between x13 and x1*x3 by 2 and selects symbols whose angles are within Φd from x1 and x3, respectively, as the candidate symbols,
and the second decoder computes
R
2
=
β
*
⁢
1
2
⁢
r
1
-
α
⁢
⁢
r
2
*
+
β
⁢
1
2
⁢
r
3
*
+
ν
*
⁢
γ
*
⁢
r
4
R
4
=
γ
*
⁢
r
1
-
νβ
⁢
1
2
⁢
r
2
*
-
α
⁢
⁢
r
3
*
-
β
⁢
1
2
⁢
r
4
R
24
=
-
(
C
2
+
C
4
)
2
C
2
=
-
αβ
*
⁢
2
+
να
*
⁢
β
⁢
2
C
4
=
-
νγβ
*
⁢
2
+
γ
*
⁢
β
⁢
2
where α, β and γ are the channel gains, r1, r2, r3 and r4 are the received signals, and v is the predetermined phase value by which the transmitter rotates the phases of the symbols, and R and C are variables,
outputs a symbol pair (x2, x4) if x2*x4=x24, x2 being the closest symbol to R2, x4 being the closest symbol to R4, and x24 being the closest symbol to R24, and if x2*x4≠x13, computes an angle Φd′ by dividing the angle between x24 and x2*x4 by 2 and selects symbols whose angles are within Φd′ from x2 and x4, respectively, as the candidate symbols.

227 more elements

A receiver for receiving PSK (Phase Shift Keying) modulation symbols whose phases are rotated once from a transmitter in a wireless communication system, comprising:

first and second decoders for selecting candidate symbol pairs among all possible symbol pairs using signals received by a receive antenna from four transmit antennas for four time periods and channel gains from the transmit antennas to the receive antenna, and detecting symbol pairs that minimize maximum likelihood (ML) decoding metrics over the candidate symbol pairs,
wherein the first decoder computes
R
1
=
α
*
⁢
r
1
+
β
⁢
⁢
r
2
*
+
ζ
⁢
⁢
r
3
*
-
ν
*
⁢
γ
*
⁢
r
4
R
3
=
νζ
⁢
⁢
r
2
*
+
γ
*
⁢
r
1
+
α
*
⁢
r
4
-
β
⁢
⁢
r
3
*
R
13
=
-
(
C
1
+
C
3
)
C
1
=
α
*
⁢
γν
+
αγ
*
C
3
=
ζβ
*
⁢
ν
-
ζ
*
⁢
β
where α, β, γ and ξ are the channel gains, r1, r2, r3 and r4 are the received signals, and v is a predetermined phase value by which the transmitter rotates the phases of the symbols, and R and C are variables,
outputs a symbol pair (x1, x3) if x1*x3=x13, x1 being the closest symbol to R1, x3 being the closest symbol to R3, and x13 being the closest symbol to R13, and if x1*x3≠x13, computes an angle Φd by dividing the angle between x13 and x1*x3 by 2 and selects symbols whose angles are within Φd from x1 and x3, respectively, as the candidate symbols,
and the second decoder computes
R
2
=
β
*
⁢
r
1
-
α
⁢
⁢
r
2
*
+
γ
⁢
⁢
r
3
*
+
ν
*
⁢
ζ
*
⁢
r
4
R
4
=
ζ
*
⁢
r
1
-
νγ
⁢
⁢
r
2
*
-
α
⁢
⁢
r
3
*
-
β
*
⁢
r
4
R
24
=
-
(
C
2
+
C
4
)
C
2
=
-
αγ
*
+
να
*
⁢
γ
C
4
=
-
νζβ
*
+
ζ
*
⁢
β
where α, β, γ and ξ are the channel gains, r1, r2, r3 and r4 are the received signals, and v is the predetermined phase value by which the transmitter rotates the phases of the symbols, and R and C are variables,
outputs a symbol pair (x2, x4) if x2*x4=x24, x2 being the closest symbol to R2, x4 being the closest symbol to R4, and x24 being the closest symbol to R24, and if x2*x4≠x13, computes an angle Φd′ by dividing the angle between x24 and x2*x4 by 2 and selects symbols whose angles are within Φd′ from x2 and x4, respectively as the candidate symbols.

188 more elements

Dependencies are inferred from the claim text.

Transmitting and receiving apparatus for supporting transmit antenna diversity using space-time block code

Life of this patent

Transmitting and receiving apparatus for supporting transmit antenna diversity using space-time block code

Life of this patent

Abstract

Claims12