US 8,571,121 B2Granted

Method for SER approximation for OSTBC in distributed wire communication systems

AssigneeSamsung Electronics Co., Ltd.

InventorsShuangfeng Han, Seong-Taek Hwang, Han-Lim Lee

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Abstract

A method for Symbol Error Rate (SER) approximation of an SER-based transmission power allocation operation for an Orthogonal Space Time Block Code in a DWCS equipped with multiple transmission Distributed Antennas (DA) geographically dispersed at random. The method for SER approximation includes the steps of: setting multiple combinable antenna subsets from the multiple DAs; selecting a quasi-optimal antenna subset Ag (1≦g≦2n−1) having a quasi-optimal power allocation weight wg based on predetermined power allocation, for each of the set multiple antenna subsets; and calculating an SER approximation value of the selected quasi-optimal antenna subset by applying a Probability Density Function (PDF) of a Signal-to-Noise Ratio (SNR) to the OSTBC SER having symbol constellation of a predetermined modulation scheme. The output of the SER approximation value can be output to a transmitter, or to a space-time encoder of a central processor for optimal power transmission.

Claims12

Dependent claims

A method for Symbol Error Rate (SER) approximation of an SER-based transmission power allocation operation for an Orthogonal Space Time Block Code (OSTBC) in a Distributed Wireless Communication System (DWCS) equipped with multiple transmission Distributed Antennas (DA) geographically dispersed at random, the method for SER approximation comprising the steps of:

setting a plurality of multiple combinable antenna subsets from dispersed multiple Das;
selecting quasi-optimal antenna subsets, each quasi-optimal antenna subset Ag (1≦g≦2n−1) having a quasi-optimal power allocation weight wg based on a predetermined power allocation, for each one of the plurality of multiple combinable antenna subsets;
calculating a plurality of SER approximation values of the selected quasi-optimal antenna subsets by applying a Probability Density Function (PDF) of a Signal-to-Noise Ratio (SNR) to a OSTBC SER having a symbol constellation of a predetermined modulation scheme;
determining an optimal SER approximation value to be equal to a minimum of the plurality of SER approximation values;
and
outputting the optimal SER approximation value to an encoder for optimal power allocation based on the optimal SER approximation value;
wherein the OSTBC SER includes at least one among an OSTBC SER having Multiple Quadrature Amplitude Modulation (MQAM) symbols, an OSTBC SER having M-ary Phase Shift Keying (MPSK) symbols, an OSTBC SER having Binary Phase Shift Keying (BPSK) symbols, and an OSTBC SER having Quadrature Phase Shift Keying (QPSK) symbols;
and
wherein the PDF of the SNR is defined by
f
η
⁡
(
x
)
≈
∏
j
=
1
g
⁢
⁢
(
∫
-
∞
+
∞
⁢
(
1
-
si
⁢
⁢
Ω
j
⁢
w
j
⁢
q
j
⁢
ρ
/
m
j
)
-
gm
j
⁢
m
⁢
ⅇ
-
ⅈ
⁢
⁢
sx
⁢
⁢
ⅆ
s
)
1
g
=
x
m
⁢
∑
j
=
1
g
⁢
⁢
m
j
-
1
⁢
∏
j
=
1
g
⁢
⁢
(
Γ
⁡
(
gm
j
⁢
m
)
)
-
1
g
⁢
(
Ω
j
⁢
w
j
⁢
q
j
⁢
ρ
m
j
)
-
m
j
⁢
m
⁢
ⅇ
-
m
j
⁢
x
Ω
j
⁢
w
j
⁢
q
j
⁢
ρ
⁢
⁢
g
=
x
m
⁢
∑
j
=
1
g
⁢
⁢
m
j
-
1
⁢
ⅇ
-
∑
j
=
1
g
⁢
⁢
m
j
⁢
x
Ω
j
⁢
w
j
⁢
q
j
⁢
ρ
⁢
⁢
g
⁢
∏
j
=
1
g
⁢
⁢
(
Γ
⁡
(
gm
j
⁢
m
)
)
-
1
g
⁢
(
Ω
j
⁢
w
j
⁢
q
j
⁢
ρ
m
j
)
-
m
j
⁢
m
=
x
D
-
1
⁢
ⅇ
-
x
⁢
⁢
C
2
⁢
C
1
,
⁢
wherein
D
=
m
⁢
∑
j
=
1
g
⁢
⁢
m
j
,
⁢
C
1
=
∏
j
=
1
g
⁢
⁢
(
Γ
⁡
(
gm
j
⁢
m
)
)
-
1
g
⁢
(
Ω
j
⁢
w
j
⁢
q
j
⁢
ρ
/
m
j
)
-
m
j
⁢
m
,
⁢
C
2
=
∑
j
=
1
g
⁢
⁢
m
j
/
Ω
j
⁢
w
j
⁢
q
j
⁢
ρ
⁢
⁢
g
,
⁢
η
=
SNR
,
⁢
f
η
⁡
(
x
)
=
PDF
⁢
⁢
of
⁢
⁢
η
,
wj=corresponding power allocation weight,
ρ=Transmit Power to Receive Noise Ratio (TSNR),
mj=corresponding Nakagami fading parameter,
Ωj=the jth DA for large-scale fading, and
g=combination of optimal DAs.

358 more elements

setting a plurality of multiple combinable antenna subsets from dispersed multiple DAs;
selecting quasi-optimal antenna subsets, each quasi-optimal antenna subset Ag (1≦g≦2n−1) having a quasi-optimal power allocation weight wg based on a predetermined power allocation, for each one of the plurality of multiple combinable antenna subsets;
calculating a plurality of SER approximation values of the selected quasi-optimal antenna subsets by applying a Probability Density Function (PDF) of a Signal-to-Noise Ratio (SNR) to a OSTBC SER having a symbol constellation of a predetermined modulation scheme;
determining an optimal SER approximation value to be equal to a minimum of the plurality of SER approximation values;
and
outputting the optimal SER approximation value to an encoder for optimal power allocation based on the optimal SER approximation value;
wherein the OSTBC SER includes at least one among an OSTBC SER having Multiple Quadrature Amplitude Modulation (MQAM) symbols, an OSTBC SER having M-ary Phase Shift Keying (MPSK) symbols, an OSTBC SER having Binary Phase Shift Keying (BPSK) symbols, and an OSTBC SER having Quadrature Phase Shift Keying (QPSK) symbols;
and
wherein the OSTBC SER having the at least one among an OSTBC SER having Multiple Quadrature Amplitude Modulation (MQAM) symbols, the OSTBC SER having M-ary Phase Shift Keying (MPSK) symbols, the OSTBC SER having Binary Phase Shift Keying (BPSK) symbols, and the OSTBC SER having Quadrature Phase Shift Keying (QPSK) symbols, is defined by
⁢
P
MQAM
=
1
-
(
1
-
∫
0
∞
⁢
2
⁢
(
1
-
1
M
)
⁢
Q
⁡
(
3
M
-
1
⁢
x
)
⁢
f
η
⁡
(
x
)
⁢
ⅆ
x
)
2
,
⁢
P
M
g
⁢
PSK
=
∫
0
∞
⁢
(
2
⁢
Q
⁡
(
2
⁢
x
⁢
sin
⁢
π
M
g
)
-
1
π
⁢
∫
π
2
-
π
M
g
π
2
⁢
ⅇ
-
x
⁡
(
sin
⁢
π
M
g
)
/
cos
2
⁢
θ
⁢
ⅆ
θ
)
⁢
f
η
⁡
(
x
)
⁢
ⅆ
x
,
⁢
⁢
P
BPSK
≈
∫
0
∞
⁢
Q
⁡
(
2
⁢
x
)
⁢
f
η
⁡
(
x
)
⁢
ⅆ
x
,
and
⁢
P
QPSK
≈
1
2
⁢
∫
0
∞
⁢
Q
⁡
(
x
)
⁢
f
η
⁡
(
x
)
⁢
ⅆ
x
,
respectively
,
wherein
η=SNR,
fη(x)=PDF of η, and
M=M-ary level of MQAM and MPSK.

184 more elements

setting a plurality of multiple combinable antenna subsets from dispersed multiple DAs;
selecting quasi-optimal antenna subsets, each quasi-optimal antenna subset Ag (1≦g≦2n=1) having a quasi-optimal power allocation weight wg based on a predetermined power allocation, for each one of the plurality of multiple combinable antenna subsets;
calculating a plurality of SER approximation values of the selected quasi-optimal antenna subsets by applying a Probability Density Function (PDF) of a Signal-to-Noise Ratio (SNR) to a OSTBC SER having a symbol constellation of a predetermined modulation scheme;
determining an optimal SER approximation value to be equal to a minimum of the plurality of SER approximation values;
and
outputting the optimal SER approximation value to an encoder for optimal power allocation based on the optimal SER approximation value;
wherein the OSTBC SER includes at least one among an OSTBC SER having Multiple Quadrature Amplitude Modulation (MQAM) symbols, an OSTBC SER having M-ary Phase Shift Keying (MPSK) symbols, an OSTBC SER having Binary Phase Shift Keying (BPSK) symbols, and an OSTBC SER having Quadrature Phase Shift Keying (QPSK) symbols;
and
wherein the plurality of SER approximation values obtained by applying the PDF of the SNR to the OSTBC SER having symbols of MQAM, MPSK, BPSK, and QPSK are defined by
P
M
g
-
QAM
A
g
≈
1
-
(
1
-
C
1
⁢
Γ
⁡
(
D
)
⁢
(
C
2
)
-
D
×
(
1
-
1
M
g
)
⁢
(
1
-
∑
t
=
0
D
-
1
⁢
μ
⁡
(
1
-
μ
2
4
)
t
⁢
(
2
⁢
t
t
)
)
)
2
,
⁢
P
M
g
-
PSK
A
g
≈
C
1
⁢
Γ
⁡
(
D
)
⁢
(
C
2
)
-
D
⁢
(
1
-
∑
t
=
0
D
-
1
⁢
(
1
+
C
2
/
sin
2
⁡
(
π
/
M
g
)
)
-
0.5
⁢
(
1
-
(
1
+
C
2
/
sin
2
⁡
(
π
/
M
g
)
)
-
1
4
)
t
⁢
(
2
⁢
t
t
)
)
,
⁢
P
BPSK
A
g
≈
1
2
⁢
C
1
⁢
Γ
⁡
(
D
)
⁢
(
C
2
)
-
D
⁢
(
1
-
∑
t
=
0
D
-
1
⁢
(
1
+
C
2
)
-
0.5
⁢
(
1
-
(
1
+
C
2
)
-
1
4
)
t
⁢
(
2
⁢
t
t
)
)
,
⁢
and
P
QPSK
A
g
≈
1
4
⁢
C
1
⁢
Γ
⁡
(
D
)
⁢
(
C
2
)
-
D
⁢
(
1
-
∑
t
=
0
D
-
1
⁢
(
1
+
2
⁢
C
2
)
-
0.5
⁢
(
1
-
(
1
+
2
⁢
C
2
)
-
1
4
)
t
⁢
(
2
⁢
t
t
)
)
,
⁢
respectively
,
wherein
D
=
m
⁢
∑
j
=
1
g
⁢
m
j
,
⁢
C
2
=
∑
j
=
1
g
⁢
m
j
/
Ω
j
⁢
w
j
⁢
q
j
⁢
ρ
⁢
⁢
g
,
⁢
C
1
=
∏
j
=
1
g
⁢
⁢
(
Γ
⁡
(
gm
j
⁢
m
)
)
-
1
g
⁢
(
Ω
j
⁢
w
j
⁢
q
j
⁢
ρ
/
m
j
)
-
m
j
⁢
m
,
μ=√{square root over (3/(3+2C2(Mg−1)))},
M=M-ary level of MQAM and MPSK,
wj =corresponding power allocation weight,
ρ=Transmit Power to Receive Noise Ratio (TSNR),
mj=corresponding parameter of Nakagami fading,
Ωj=large-scale fading for the jth DA, and
g=combination of optimal DAs.

401 more elements

setting a plurality of multiple combinable antenna subsets from dispersed multiple DAs;
selecting quasi-optimal antenna subsets, each quasi-optimal antenna subset Ag (1≦g≦2n−1) having a quasi-optimal power allocation weight wg based on a predetermined power allocation, for each one of the plurality of multiple combinable antenna subsets;
calculating a plurality of SER approximation values of the selected quasi-optimal antenna subsets by applying a Probability Density Function (PDF) of a Signal-to-Noise Ratio (SNR) to a OSTBC SER having a symbol constellation of a predetermined modulation scheme;
determining an optimal SER approximation value to be equal to a minimum of the plurality of SER approximation values;
and
outputting the optimal SER approximation value to an encoder for optimal power allocation based on the optimal SER approximation value;
wherein the OSTBC SER includes at least one among an OSTBC SER having Multiple Quadrature Amplitude Modulation (MQAM) symbols, an OSTBC SER having M-ary Phase Shift Keying (MPSK) symbols, an OSTBC SER having Binary Phase Shift Keying (BPSK) symbols, and an OSTBC SER having Quadrature Phase Shift Keying (QPSK) symbols;
wherein, when the plurality of SER approximation values are calculated by applying the PDF of the SNR to the OSTBC SER having symbols of MQAM and MPSK, the SER approximation values are obtained by omitting e−xC2 from the PDF of the SNR in a high TSNR region, as defined by
P
M
g
-
QAM
A
g
⁡
(
High
⁢
⁢
_ρ
)
=
1
-
(
1
-
∏
t
=
1
D
⁢
⁢
(
2
⁢
D
-
(
2
⁢
t
-
1
)
)
D
⁢
(
1
-
1
M
g
)
⁢
(
3
M
g
-
1
)
-
D
⁢
C
1
)
2
,
⁢
and
P
M
g
-
PSK
A
g
⁡
(
High
⁢
⁢
_ρ
)
=
∏
t
=
1
D
⁢
⁢
(
2
⁢
D
-
(
2
⁢
t
-
1
)
)
D
⁢
(
2
⁢
sin
2
⁡
(
π
/
M
g
)
)
-
D
⁢
C
1
,
respectively
,
⁢
wherein
D
=
m
⁢
∑
j
=
1
g
⁢
m
j
,
⁢
C
1
=
∏
j
=
1
g
⁢
⁢
(
Γ
⁡
(
gm
j
⁢
m
)
)
-
1
g
⁢
(
Ω
j
⁢
w
j
⁢
q
j
⁢
ρ
/
m
j
)
-
m
j
⁢
m
,
⁢
C
2
=
∑
j
=
1
g
⁢
m
j
/
Ω
j
⁢
w
j
⁢
q
j
⁢
ρ
⁢
⁢
g
,
wj=corresponding power allocation weight,
ρ=Transmit Power to Receive Noise Ratio (TSNR),
mj=corresponding parameter of Nakagami fading,
Ωj=larg-scale fading for the jth DA, and
g=combination of optimal DAs.

223 more elements

Dependencies are inferred from the claim text.

Facts

Application: 12/034,723Filed 21 Feb 2008
Priority: KR 10-2007-001793822 Feb 2007
Published: US 2008/0205538 A128 Aug 2008
Granted: 29 Oct 2013
Term ends: Not estimatedThe source records don’t support an estimate.

Classification7 codes

H04L 1/20
Arrangements for detecting or preventing errors in the information received: using signal quality detector
H04L 1/0618
Using space diversity: space-time coding
H04B 7/0443
Using multiple eigenmodes: utilizing "waterfilling" technique
Y02D 30/70
Reducing energy consumption in communication networks: in wireless communication networks