US 8,509,352 B2 · Integer spreading rotation matrices for QAM constellations and its decode-remodulate-forward cooperative communication strategy

Abstract

Diversity techniques are commonly used in wireless communications to combat multipath fading. Recent interests in ultra-wideband technology focus on multi-band OFDM systems that can explore the high diversity due to the independent frequency bands. To achieve full diversity with high data rate, a system, apparatus and method that uses coded modulation with spreading rotation of transmitted signals. A 2×2 integer rotation matrix for QAM signals, 3×3 and 4×4 integer rotation matrices for QAM signals are provided. Compared with the non-regular QAM shape for real rotation matrices, each of these integer rotation matrices makes the regular QAM shape after rotation.

Claims24

Dependent claims

A system for increasing a diversity of a communication system using QAM modulation, comprising:

a receiver device to receive and jointly decode N spread QAM symbols received over N different independent channels;
and
a transmitter device to spread and rotate N QAM symbols and then transmit the N spread and rotated QAM symbols over N different independent channels,
wherein the transmitter device further comprises a spreading rotation component to multiply the N QAM symbols by a pre-specified N×N integer spreading rotation matrix,
wherein, the diversity for the communication system is optimally increased while maintaining the same transmission rate, and
wherein the pre-specified N×N integer spreading rotation matrix is the integer 2×2 integer spreading rotation matrix
I
16
,
2
=
1
17
⁡
[
4
⁢
1
1
-
4
]
which spreads 16-QAM symbols into regular 256-QAM symbols, and the 2×2 integer spreading rotation matrix that spreads 64-QAM symbols and 256-QAM symbols are
I
64
,
2
=
1
65
⁡
[
8
1
1
-
8
]
⁢
⁢
and
⁢
⁢
I
256
,
2
=
1
257
⁡
[
16
1
1
-
16
]
respectively.

56 more elements

A system for increasing a diversity of a communication system using QAM modulation, comprising:

a receiver device to receive and jointly decode N spread QAM symbols received over N different independent channels;
and
a transmitter device to spread and rotate N QAM symbols and then transmit the N spread and rotated QAM symbols over N different independent channels,
wherein the transmitter device further comprises a spreading rotation component to multiply the N QAM symbols by a pre-specified N×N integer spreading rotation matrix, wherein, the diversity for the communication system is optimally increased while maintaining the same transmission rate;
and
wherein the pre-specified N×N integer spreading rotation matrix is:
the integer 3×3 rotation matrix selected from the group of matrices consisting of
I
4
,
3
=
1
21
⁡
[
4
2
-
1
-
1
4
2
2
1
4
]
,
1
21
⁡
[
4
-
2
1
1
4
-
2
2
1
4
]
and any permutation of these two matrices between rows or columns, which spread 4-QAM symbols into regular 64-QAM symbols, and
the 3×3 integer spreading rotation matrices that can spread 16-QAM symbols, 64-QAM symbols and three 256-QAM symbols are, respectively selected from the respective group consisting of:
I
16
,
3
=
1
273
⁡
[
16
4
-
1
-
1
16
4
4
-
1
16
]
,
1
273
⁡
[
16
-
4
1
1
16
-
4
-
4
1
16
]
I
64
,
3
=
1
4161
⁡
[
64
8
-
1
-
1
64
8
8
-
1
64
]
,
1
4161
⁡
[
64
-
8
1
1
64
-
8
-
8
1
64
]
I
256
,
3
=
1
65793
⁡
[
256
16
-
1
-
1
256
16
16
-
1
256
]
,
1
65793
⁡
[
256
-
16
1
1
256
-
16
-
16
1
256
]
and any permutation of each above matrix between rows or columns.

165 more elements

A system for increasing a diversity of a communication system using QAM modulation, comprising:

a receiver device to receive and jointly decode N spread QAM symbols received over N different independent channels;
and
a transmitter device to spread and rotate N QAM symbols and then transmit the N spread and rotated QAM symbols over N different independent channels,
wherein the transmitter device further comprises a spreading rotation component to multiply the N QAM symbols by a pre-specified N×N integer spreading rotation matrix, wherein, the diversity for the communication system is optimally increased while maintaining the same transmission rate;
and
wherein the N×N integer spreading rotation matrix is:
a 4×4 integer spreading matrix such that all 4×4 integer rotation matrices for four QAM symbols are of the type
I
4
,
4
=
1
85
⁡
[
x
1
x
2
x
3
x
4
-
x
2
x
1
-
x
4
x
3
-
x
3
x
4
x
1
-
x
2
-
x
4
-
x
3
x
2
x
1
]
where x1, x2, x3, x4ε{±1,±2,±4,±8} and their absolute value must be different from each other, and
all 4×4 integer rotation matrices for 16-QAM symbols are of the type
I
16
,
4
=
1
4369
⁡
[
x
1
x
2
x
3
x
4
-
x
2
x
1
-
x
4
x
3
-
x
3
x
4
x
1
-
x
2
-
x
4
-
x
3
x
2
x
1
]
where x1, x2, x3, x4ε{±1,±4,±16,±64} and their absolute value must be different from each other, and
all 4×4 integer rotation matrices for 64-QAM symbols are of the type
I
64
,
4
=
1
266305
⁡
[
x
1
x
2
x
3
x
4
-
x
2
x
1
-
x
4
x
3
-
x
3
x
4
x
1
-
x
2
-
x
4
-
x
3
x
2
x
1
]
where x1, x2, x3, x4ε{±1,±8,±64,±512} and their absolute value must be different from each other, and
all 4×4 integer rotation matrices for 256-QAM symbols are of the type
I
256
,
4
=
1
16843009
⁡
[
x
1
x
2
x
3
x
4
-
x
2
x
1
-
x
4
x
3
-
x
3
x
4
x
1
-
x
2
-
x
4
-
x
3
x
2
x
1
]
where x1 , x2, x3, x4ε{±1,±16,±256,±4096} and their absolute value must be different from each other.

203 more elements

A method for increasing a diversity of a communication system using QAM modulation, comprising the steps of:

spreading and rotating N QAM symbols by multiplication of each symbol by a pre-specified N×N spreading rotation matrix R;
and
transmitting the N spread and rotated symbols over N different independent channels,
wherein the multiplication of the N QAM symbols is performed by a pre-specified N×N integer spreading rotation matrix,
wherein the diversity for the communication system is optimally increased while maintaining the same transmission rate;
and
wherein for a 3×3 matrix R for 4-QAM symbols:
the 3×3 integer rotation matrix is selected from the group of matrices consisting of
I
4
,
3
=
1
21
⁡
[
4
2
-
1
-
1
4
2
2
-
1
4
]
,
1
21
⁡
[
4
-
2
1
1
4
-
2
-
2
1
4
]
and any permutation of these two matrices between rows or columns, which spread 4-QAM symbols into regular 64-QAM symbols, and
the 3×3 integer spreading rotation matrix that spreads 16-QAM symbols, 64-QAM symbols and three 256-QAM symbols are respectively
I
16
,
3
=
1
273
⁡
[
16
4
-
1
-
1
16
4
4
-
1
16
]
,
1
273
⁡
[
16
-
4
1
1
16
-
4
-
4
1
16
]
I
64
,
3
=
1
4161
⁡
[
64
8
-
1
-
1
64
8
8
-
1
64
]
,
1
4161
⁡
[
64
-
8
1
1
64
-
8
-
8
1
64
]
I
256
,
3
=
1
65793
⁡
[
256
16
-
1
-
1
256
16
16
-
1
256
]
,
1
65793
⁡
[
256
-
16
1
1
256
-
16
-
16
1
256
]
and any permutation of each above matrix between rows or columns.

168 more elements

A method for increasing a diversity of a communication system using QAM modulation, comprising the steps of:

spreading and rotating N QAM symbols by multiplication of each symbol by a pre-specified N×N spreading rotation matrix R;
and
transmitting the N spread and rotated symbols over N different independent channels,
wherein the multiplication of the N QAM symbols is performed by a pre-specified N×N integer spreading rotation matrix,
wherein the diversity for the communication system is optimally increased while maintaining the same transmission rate;
and
wherein for a 4×4 matrix R for QAM symbols, the matrix R is
all 4×4 integer rotation matrices for four QAM symbols are of the type
I
4
,
4
=
1
85
⁡
[
x
1
x
2
x
3
x
4
-
x
2
x
1
-
x
4
x
3
-
x
3
x
4
x
1
-
x
2
-
x
4
-
x
3
x
2
x
1
]
where x1, x2, x3, x4ε{±1,±2,±4,±8} and their absolute value must be different from each other, and
all 4×4 integer rotation matrices for 16-QAM symbols are of the type
I
16
,
4
=
1
4369
⁡
[
x
1
x
2
x
3
x
4
-
x
2
x
1
-
x
4
x
3
-
x
3
x
4
x
1
-
x
2
-
x
4
-
x
3
x
2
x
1
]
where x1, x2, x3, x4ε{±1,±4,±16,±64} and their absolute value must be different from each other, and
all 4×4 integer rotation matrices for 64-QAM symbols are of the type
I
64
,
4
=
1
266305
⁡
[
x
1
x
2
x
3
x
4
-
x
2
x
1
-
x
4
x
3
-
x
3
x
4
x
1
-
x
2
-
x
4
-
x
3
x
2
x
1
]
where x1, x2, x3, x4ε{±1,±8,±64,±512} and their absolute value must be different from each other, and
all 4×4 integer rotation matrices for 256-QAM symbols are of the type
I
256
,
4
=
1
16843009
⁡
[
x
1
x
2
x
3
x
4
-
x
2
x
1
-
x
4
x
3
-
x
3
x
4
x
1
-
x
2
-
x
4
-
x
3
x
2
x
1
]
where x1, x2, x3, x4ε{±1,±16,±256,±4096} and their absolute value must be different from each other.

204 more elements

A transmitter for increasing a diversity of a communication system using QAM modulation, comprising:

a spreader to spread and rotate N QAM symbols;
and
an allocation component to allocate the N spread and rotated QAM symbols over N different independent channels for transmission thereover,
wherein the spreader is further configured to multiply the N QAM symbols by a pre-specified N×N integer spreading rotation matrix,
wherein, the diversity for the communication system is optimally increased while maintaining the same transmission rate;
and
wherein the pre-specified N×N integer spreading rotation matrix is:
a 3×3 integer spreading rotation matrix selected from the group of matrices consisting of
I
4
,
3
=
1
21
⁡
[
4
2
-
1
-
1
4
2
2
-
1
4
]
,
1
21
⁡
[
4
-
2
1
1
4
-
2
-
2
1
4
]
and any permutation of these two matrices between rows or columns, which spread 4-QAM symbols into regular 64-QAM symbols, and
a 3×3 integer spreading rotation matrix that spreads 16-QAM symbols, 64-QAM symbols and three 256-QAM symbols respectively selected from the respective group consisting of
I
16
,
3
=
1
273
⁡
[
16
4
-
1
-
1
16
4
4
-
1
16
]
,
1
273
⁡
[
16
-
4
1
1
16
-
4
-
4
1
16
]
I
64
,
3
=
1
4161
⁡
[
64
8
-
1
-
1
64
8
8
-
1
64
]
,
1
4161
⁡
[
64
-
8
1
1
64
-
8
-
8
1
64
]
I
256
,
3
=
1
65793
⁡
[
256
16
-
1
-
1
256
16
16
-
1
256
]
,
1
65793
⁡
[
256
-
16
1
1
256
-
16
-
16
1
256
]
and any permutation of each above matrix between rows or columns.

168 more elements

A transmitter for increasing a diversity of a communication system using QAM modulation, comprising:

a spreader to spread and rotate N QAM symbols;
and
an allocation component to allocate the N spread and rotated QAM symbols over N different independent channels for transmission thereover,
wherein the spreader is further configured to multiply the N QAM symbols by a pre-specified N×N integer spreading rotation matrix,
wherein, the diversity for the communication system is optimally increased while maintaining the same transmission rate;
and
wherein the pre-specified N×N integer spreading rotation matrix is:
all 4×4 integer rotation matrices for 4-QAM symbols of the type
I
4
,
4
=
1
85
⁡
[
x
1
x
2
x
3
x
4
-
x
2
x
1
-
x
4
x
3
-
x
3
x
4
x
1
-
x
2
-
x
4
-
x
3
x
2
x
1
]
where x1, x2, x3, x4ε{±1,±2,±4,±8} and their absolute value must be different from each other, and
all 4×4 integer rotation matrices for 16-QAM symbols of the type
I
16
,
4
=
1
4369
⁡
[
x
1
x
2
x
3
x
4
-
x
2
x
1
-
x
4
x
3
-
x
3
x
4
x
1
-
x
2
-
x
4
-
x
3
x
2
x
1
]
where x1, x2, x3, x4ε{±1,±4,±16,±64} and their absolute value must be different from each other, and
all 4×4 integer rotation matrices for 64-QAM symbols of the type
I
64
,
4
=
1
266305
⁡
[
x
1
x
2
x
3
x
4
-
x
2
x
1
-
x
4
x
3
-
x
3
x
4
x
1
-
x
2
-
x
4
-
x
3
x
2
x
1
]
where x1, x2, x3, x4ε{±1,±8,±64,±512} and their absolute value must be different from each other, and
all 4×4 integer rotation matrices for 256-QAM symbols of the type:
I
256
,
4
=
1
16843009
⁡
[
x
1
x
2
x
3
x
4
-
x
2
x
1
-
x
4
x
3
-
x
3
x
4
x
1
-
x
2
-
x
4
-
x
3
x
2
x
1
]
where x1, x2, x3, x4ε{±1,±16,±256,±4096} and their absolute value must be different from each other.

204 more elements

Dependencies are inferred from the claim text.

Facts

Application

12/096,975Filed 8 Dec 2006 · us provisional application

Priority

12 Dec 2005

Published

US 2008/0317168 A125 Dec 2008

Granted

13 Aug 2013

Term ends

Not estimatedThe source records don’t support an estimate.

Classification8 codes

H04B 7/026
Site diversity; Macro-diversity: co-operative diversity, e.g. using fixed or mobile stations as relays
H04B 7/0848
Weighted combining: joint weighting
H04B 7/15592
Ground-based stations: adapting at the relay station communication parameters for supporting cooperative relaying, i.e. transmission of the same…
H04L 27/2626
Multicarrier modulation systems: arrangements specific to the transmitter only

Abstract

Claims24

Dependent claims

A system for increasing a diversity of a communication system using QAM modulation, comprising:

a receiver device to receive and jointly decode N spread QAM symbols received over N different independent channels;
and
a transmitter device to spread and rotate N QAM symbols and then transmit the N spread and rotated QAM symbols over N different independent channels,
wherein the transmitter device further comprises a spreading rotation component to multiply the N QAM symbols by a pre-specified N×N integer spreading rotation matrix,
wherein, the diversity for the communication system is optimally increased while maintaining the same transmission rate, and
wherein the pre-specified N×N integer spreading rotation matrix is the integer 2×2 integer spreading rotation matrix
I
16
,
2
=
1
17
⁡
[
4
⁢
1
1
-
4
]
which spreads 16-QAM symbols into regular 256-QAM symbols, and the 2×2 integer spreading rotation matrix that spreads 64-QAM symbols and 256-QAM symbols are
I
64
,
2
=
1
65
⁡
[
8
1
1
-
8
]
⁢
⁢
and
⁢
⁢
I
256
,
2
=
1
257
⁡
[
16
1
1
-
16
]
respectively.

56 more elements

A system for increasing a diversity of a communication system using QAM modulation, comprising:

a receiver device to receive and jointly decode N spread QAM symbols received over N different independent channels;
and
a transmitter device to spread and rotate N QAM symbols and then transmit the N spread and rotated QAM symbols over N different independent channels,
wherein the transmitter device further comprises a spreading rotation component to multiply the N QAM symbols by a pre-specified N×N integer spreading rotation matrix, wherein, the diversity for the communication system is optimally increased while maintaining the same transmission rate;
and
wherein the pre-specified N×N integer spreading rotation matrix is:
the integer 3×3 rotation matrix selected from the group of matrices consisting of
I
4
,
3
=
1
21
⁡
[
4
2
-
1
-
1
4
2
2
1
4
]
,
1
21
⁡
[
4
-
2
1
1
4
-
2
2
1
4
]
and any permutation of these two matrices between rows or columns, which spread 4-QAM symbols into regular 64-QAM symbols, and
the 3×3 integer spreading rotation matrices that can spread 16-QAM symbols, 64-QAM symbols and three 256-QAM symbols are, respectively selected from the respective group consisting of:
I
16
,
3
=
1
273
⁡
[
16
4
-
1
-
1
16
4
4
-
1
16
]
,
1
273
⁡
[
16
-
4
1
1
16
-
4
-
4
1
16
]
I
64
,
3
=
1
4161
⁡
[
64
8
-
1
-
1
64
8
8
-
1
64
]
,
1
4161
⁡
[
64
-
8
1
1
64
-
8
-
8
1
64
]
I
256
,
3
=
1
65793
⁡
[
256
16
-
1
-
1
256
16
16
-
1
256
]
,
1
65793
⁡
[
256
-
16
1
1
256
-
16
-
16
1
256
]
and any permutation of each above matrix between rows or columns.

165 more elements

A system for increasing a diversity of a communication system using QAM modulation, comprising:

a receiver device to receive and jointly decode N spread QAM symbols received over N different independent channels;
and
a transmitter device to spread and rotate N QAM symbols and then transmit the N spread and rotated QAM symbols over N different independent channels,
wherein the transmitter device further comprises a spreading rotation component to multiply the N QAM symbols by a pre-specified N×N integer spreading rotation matrix, wherein, the diversity for the communication system is optimally increased while maintaining the same transmission rate;
and
wherein the N×N integer spreading rotation matrix is:
a 4×4 integer spreading matrix such that all 4×4 integer rotation matrices for four QAM symbols are of the type
I
4
,
4
=
1
85
⁡
[
x
1
x
2
x
3
x
4
-
x
2
x
1
-
x
4
x
3
-
x
3
x
4
x
1
-
x
2
-
x
4
-
x
3
x
2
x
1
]
where x1, x2, x3, x4ε{±1,±2,±4,±8} and their absolute value must be different from each other, and
all 4×4 integer rotation matrices for 16-QAM symbols are of the type
I
16
,
4
=
1
4369
⁡
[
x
1
x
2
x
3
x
4
-
x
2
x
1
-
x
4
x
3
-
x
3
x
4
x
1
-
x
2
-
x
4
-
x
3
x
2
x
1
]
where x1, x2, x3, x4ε{±1,±4,±16,±64} and their absolute value must be different from each other, and
all 4×4 integer rotation matrices for 64-QAM symbols are of the type
I
64
,
4
=
1
266305
⁡
[
x
1
x
2
x
3
x
4
-
x
2
x
1
-
x
4
x
3
-
x
3
x
4
x
1
-
x
2
-
x
4
-
x
3
x
2
x
1
]
where x1, x2, x3, x4ε{±1,±8,±64,±512} and their absolute value must be different from each other, and
all 4×4 integer rotation matrices for 256-QAM symbols are of the type
I
256
,
4
=
1
16843009
⁡
[
x
1
x
2
x
3
x
4
-
x
2
x
1
-
x
4
x
3
-
x
3
x
4
x
1
-
x
2
-
x
4
-
x
3
x
2
x
1
]
where x1 , x2, x3, x4ε{±1,±16,±256,±4096} and their absolute value must be different from each other.

203 more elements

A method for increasing a diversity of a communication system using QAM modulation, comprising the steps of:

spreading and rotating N QAM symbols by multiplication of each symbol by a pre-specified N×N spreading rotation matrix R;
and
transmitting the N spread and rotated symbols over N different independent channels,
wherein the multiplication of the N QAM symbols is performed by a pre-specified N×N integer spreading rotation matrix,
wherein the diversity for the communication system is optimally increased while maintaining the same transmission rate;
and
wherein for a 3×3 matrix R for 4-QAM symbols:
the 3×3 integer rotation matrix is selected from the group of matrices consisting of
I
4
,
3
=
1
21
⁡
[
4
2
-
1
-
1
4
2
2
-
1
4
]
,
1
21
⁡
[
4
-
2
1
1
4
-
2
-
2
1
4
]
and any permutation of these two matrices between rows or columns, which spread 4-QAM symbols into regular 64-QAM symbols, and
the 3×3 integer spreading rotation matrix that spreads 16-QAM symbols, 64-QAM symbols and three 256-QAM symbols are respectively
I
16
,
3
=
1
273
⁡
[
16
4
-
1
-
1
16
4
4
-
1
16
]
,
1
273
⁡
[
16
-
4
1
1
16
-
4
-
4
1
16
]
I
64
,
3
=
1
4161
⁡
[
64
8
-
1
-
1
64
8
8
-
1
64
]
,
1
4161
⁡
[
64
-
8
1
1
64
-
8
-
8
1
64
]
I
256
,
3
=
1
65793
⁡
[
256
16
-
1
-
1
256
16
16
-
1
256
]
,
1
65793
⁡
[
256
-
16
1
1
256
-
16
-
16
1
256
]
and any permutation of each above matrix between rows or columns.

168 more elements

A method for increasing a diversity of a communication system using QAM modulation, comprising the steps of:

spreading and rotating N QAM symbols by multiplication of each symbol by a pre-specified N×N spreading rotation matrix R;
and
transmitting the N spread and rotated symbols over N different independent channels,
wherein the multiplication of the N QAM symbols is performed by a pre-specified N×N integer spreading rotation matrix,
wherein the diversity for the communication system is optimally increased while maintaining the same transmission rate;
and
wherein for a 4×4 matrix R for QAM symbols, the matrix R is
all 4×4 integer rotation matrices for four QAM symbols are of the type
I
4
,
4
=
1
85
⁡
[
x
1
x
2
x
3
x
4
-
x
2
x
1
-
x
4
x
3
-
x
3
x
4
x
1
-
x
2
-
x
4
-
x
3
x
2
x
1
]
where x1, x2, x3, x4ε{±1,±2,±4,±8} and their absolute value must be different from each other, and
all 4×4 integer rotation matrices for 16-QAM symbols are of the type
I
16
,
4
=
1
4369
⁡
[
x
1
x
2
x
3
x
4
-
x
2
x
1
-
x
4
x
3
-
x
3
x
4
x
1
-
x
2
-
x
4
-
x
3
x
2
x
1
]
where x1, x2, x3, x4ε{±1,±4,±16,±64} and their absolute value must be different from each other, and
all 4×4 integer rotation matrices for 64-QAM symbols are of the type
I
64
,
4
=
1
266305
⁡
[
x
1
x
2
x
3
x
4
-
x
2
x
1
-
x
4
x
3
-
x
3
x
4
x
1
-
x
2
-
x
4
-
x
3
x
2
x
1
]
where x1, x2, x3, x4ε{±1,±8,±64,±512} and their absolute value must be different from each other, and
all 4×4 integer rotation matrices for 256-QAM symbols are of the type
I
256
,
4
=
1
16843009
⁡
[
x
1
x
2
x
3
x
4
-
x
2
x
1
-
x
4
x
3
-
x
3
x
4
x
1
-
x
2
-
x
4
-
x
3
x
2
x
1
]
where x1, x2, x3, x4ε{±1,±16,±256,±4096} and their absolute value must be different from each other.

204 more elements

A transmitter for increasing a diversity of a communication system using QAM modulation, comprising:

a spreader to spread and rotate N QAM symbols;
and
an allocation component to allocate the N spread and rotated QAM symbols over N different independent channels for transmission thereover,
wherein the spreader is further configured to multiply the N QAM symbols by a pre-specified N×N integer spreading rotation matrix,
wherein, the diversity for the communication system is optimally increased while maintaining the same transmission rate;
and
wherein the pre-specified N×N integer spreading rotation matrix is:
a 3×3 integer spreading rotation matrix selected from the group of matrices consisting of
I
4
,
3
=
1
21
⁡
[
4
2
-
1
-
1
4
2
2
-
1
4
]
,
1
21
⁡
[
4
-
2
1
1
4
-
2
-
2
1
4
]
and any permutation of these two matrices between rows or columns, which spread 4-QAM symbols into regular 64-QAM symbols, and
a 3×3 integer spreading rotation matrix that spreads 16-QAM symbols, 64-QAM symbols and three 256-QAM symbols respectively selected from the respective group consisting of
I
16
,
3
=
1
273
⁡
[
16
4
-
1
-
1
16
4
4
-
1
16
]
,
1
273
⁡
[
16
-
4
1
1
16
-
4
-
4
1
16
]
I
64
,
3
=
1
4161
⁡
[
64
8
-
1
-
1
64
8
8
-
1
64
]
,
1
4161
⁡
[
64
-
8
1
1
64
-
8
-
8
1
64
]
I
256
,
3
=
1
65793
⁡
[
256
16
-
1
-
1
256
16
16
-
1
256
]
,
1
65793
⁡
[
256
-
16
1
1
256
-
16
-
16
1
256
]
and any permutation of each above matrix between rows or columns.

168 more elements

A transmitter for increasing a diversity of a communication system using QAM modulation, comprising:

a spreader to spread and rotate N QAM symbols;
and
an allocation component to allocate the N spread and rotated QAM symbols over N different independent channels for transmission thereover,
wherein the spreader is further configured to multiply the N QAM symbols by a pre-specified N×N integer spreading rotation matrix,
wherein, the diversity for the communication system is optimally increased while maintaining the same transmission rate;
and
wherein the pre-specified N×N integer spreading rotation matrix is:
all 4×4 integer rotation matrices for 4-QAM symbols of the type
I
4
,
4
=
1
85
⁡
[
x
1
x
2
x
3
x
4
-
x
2
x
1
-
x
4
x
3
-
x
3
x
4
x
1
-
x
2
-
x
4
-
x
3
x
2
x
1
]
where x1, x2, x3, x4ε{±1,±2,±4,±8} and their absolute value must be different from each other, and
all 4×4 integer rotation matrices for 16-QAM symbols of the type
I
16
,
4
=
1
4369
⁡
[
x
1
x
2
x
3
x
4
-
x
2
x
1
-
x
4
x
3
-
x
3
x
4
x
1
-
x
2
-
x
4
-
x
3
x
2
x
1
]
where x1, x2, x3, x4ε{±1,±4,±16,±64} and their absolute value must be different from each other, and
all 4×4 integer rotation matrices for 64-QAM symbols of the type
I
64
,
4
=
1
266305
⁡
[
x
1
x
2
x
3
x
4
-
x
2
x
1
-
x
4
x
3
-
x
3
x
4
x
1
-
x
2
-
x
4
-
x
3
x
2
x
1
]
where x1, x2, x3, x4ε{±1,±8,±64,±512} and their absolute value must be different from each other, and
all 4×4 integer rotation matrices for 256-QAM symbols of the type:
I
256
,
4
=
1
16843009
⁡
[
x
1
x
2
x
3
x
4
-
x
2
x
1
-
x
4
x
3
-
x
3
x
4
x
1
-
x
2
-
x
4
-
x
3
x
2
x
1
]
where x1, x2, x3, x4ε{±1,±16,±256,±4096} and their absolute value must be different from each other.

204 more elements

Dependencies are inferred from the claim text.

Integer spreading rotation matrices for QAM constellations and its decode-remodulate-forward cooperative communication strategy

Life of this patent

Abstract

Claims24

Integer spreading rotation matrices for QAM constellations and its decode-remodulate-forward cooperative communication strategy

Life of this patent

Abstract

Claims24