doc.:11-14-1365-00-00aj

Submission

November 2014

Slide 1 Shiwen He ， Haiming Wang

Quasi-Orthogonal STBC for IEEE 802.11aj （ 45GHz）

Name Company Address Phone Email Shiwen HE

Southeast University (SEU)

2 Sipailou, Nanjing 210096, China

+86-25-5209 1653-3121 (ext.) hesw01@seu.edu.cn

Haiming WANG +86-25-5209 1653-301 (ext.) hmwang@seu.edu.cn

Yongming HUANG huangym@seu.edu.cn

Shimin MA sdtzmsm@126.com

Wei HONG +86-25-5209 1650 weihong@seu.edu.cn

Bo SUN ZTE sun.bo1@zte.com.cn

Authors/contributors:

Date: 2014-11-15Presenter: Shiwen HE

doc.:11-14-1365-00-00aj

Submission

November 2014

Slide 2 Shiwen He ， Haiming Wang

- In 802.11n/ac/ad, the orthogonal STBC is widely used for improving the performance of wireless communication systems.

- The Alamouti code is the unique scheme to achieve the maximum diversity order as well as full rate transmission in case of 2 transmitting antennas.

- Some alternative schemes could be applied in systems with more than 2 antennas. These coding schemes are suboptimal as they cannot achieve full transmission rate and full diversity order simultaneously.

- One scheme of Orthogonal STBC can achieve full diversity order at a rate of 1/2.

Background

doc.:11-14-1365-00-00aj

Submission

November 2014

Slide 3 Shiwen He ， Haiming Wang

Code matrix:

- Quasi Orthogonal STBC can achieve full rate transmission with impairing diversity order. Code matrix:

The elements in each row are the symbols to be transmitted on each antenna.

* * * *4 3 2 1 4 3 2 1* * * *3 4 1 2 3 4 1 2* * * *2 1 4 3 2 1 4 3* * * *1 2 3 4 1 2 3 4

- - - - - -- -

- -- -

x x x x x x x xx x x x x x x xx x x x x x x xx x x x x x x x

* *4 3 2 1

* *3 4 1 2

* *2 1 4 3

* *1 2 3 4

- -- -- -

x x x xx x x xx x x xx x x x

doc.:11-14-1365-00-00aj

Submission

November 2014

Slide 4 Shiwen He ， Haiming Wang

Introduction-Quasi Orthogonal STBC(4×1 -1ss) t1 t2 t3 t4

-Data stream:

.... .....

* *4 3 2 1

* *3 4 1 2

* *2 1 4 3

* *1 2 3 4

- -- -- -

x x x xx x x xx x x xx x x x

1 2 3 4y , y , y , y

1

1

x

1(0)... (N-1)s s 2

2

x

2(0)... (N-1)s s 3

3

x

3(0)... (N-1)s s 4

4

x

4(0)... (N-1)s s

doc.:11-14-1365-00-00aj

Submission

November 2014

Slide 5 Shiwen He ， Haiming Wang

- Location in System：

doc.:11-14-1365-00-00aj

Submission

November 2014

Slide 6 Shiwen He ， Haiming Wang

- Code block: k-th time slot:

(k+1)-th time slot:

1 1 1 1

2 2 2 2

3 3 3 3

4 4 4 4

(n) (0) (1) ... (N-1)

(n) (0) s (1) ... (N-1)

(n) (0) (1) ... (N-1)

(n) (0) (1) ... (N-1)

k

k

k

k

s s s

s s

s s s

s s s

x

x

x

x

，，

，，

，，

，，

+ * * * *1 2 2 2 2

+ * * * *2 1 1 1 1

+ * * * *3 4 4 4 4

+4 3

(n) - ((- ) ) = - (0) s (N-1) ... (1)

( ) ((- ) ) = (0) (N-1) ... (1) 0,1... -1

( ) - ((- ) ) =- (0) (N-1) ... (1)

( ) ((

k kN

k kN

k kN

k k

n s s

n n s s s n N

n n s s s

n

x x

x x

x x

x x

（ 1） （ ）

（ 1） （ ）

（ 1） （ ）

（ 1） （ ）

* * * *3 3 3- ) ) (0) (N-1) ... (1)Nn s s s

doc.:11-14-1365-00-00aj

Submission

November 2014

Slide 7 Shiwen He ， Haiming Wang

(k+2)-th time slot:

(k+3)-th time slot:

- Then the original data can be obtained using linear processing in the receiver.

+2 * * * *1 3 3 3 3

+2 * * * *2 4 4 4 4

+2 * * * *3 1 1 1 1

+24 2

(n) - ((- ) ) = - (0) s (N-1) ... (1)

( ) - ((- ) ) = - (0) (N-1) ... (1) 0,1... -1

( ) ((- ) ) = (0) (N-1) ... (1)

( ) ((-

k kN

k kN

k kN

k k

n s s

n n s s s n N

n n s s s

n

x x

x x

x x

x x

（ ） （ ）

（ ） （ ）

（ ） （ ）

（ ） （ ）

* * * *2 2 2) ) (0) (N-1) ... (1)Nn s s s

+31 4 4 4 4

+32 3 3 3 3

+33 2 2 2 2

+34 1 1 1 1

(n) (( ) ) = (0) (1) ... (N-1)

( ) - (( ) )=- (0) (1) ... (N-1)

( ) - (( ) )=- (0) s (1) ... (N-1)

( ) (( ) ) = (0) (1) ... (N-1)

0,1..

k kN

k kN

k kN

k kN

n s s s

n n s s s

n n s s

n n s s s

n

x x

x x

x x

x x

（ ） （ ）

（ ） （ ）

（ ） （ ）

（ ） （ ）

，，

，，

，，

，，

. -1N

doc.:11-14-1365-00-00aj

Submission

November 2014

Slide 8 Shiwen He ， Haiming Wang

- Comparisons of error performance of the 4×1 system with BPSK Modulation and 1/2-rate and 1-ss.

QSTBC outperforms CSD by 0.4dB approximately.(PER=0.1) QSTBC outperforms SC-1×1 by 2.2dB approximately.(PER=0.1)

Simulation

doc.:11-14-1365-00-00aj

Submission

November 2014

Slide 9 Shiwen He ， Haiming Wang

- Comparisons of error performance of the 4×1 system with QPSK Modulation and 1/2-rate and 1-ss.

QSTBC outperforms CSD by 0.8dB approximately.(PER=0.1) QSTBC outperforms SC-1×1 by 1.2dB approximately.(PER=0.1)

doc.:11-14-1365-00-00aj

Submission

November 2014

Slide 10 Shiwen He ， Haiming Wang

- Comparisons of error performance of the 4×1 system with 16-QAM Modulation and 1/2-rate and 1-ss.

QSTBC outperforms CSD by 2dB approximately.(PER=0.1)

doc.:11-14-1365-00-00aj

Submission

November 2014

Slide 11 Shiwen He ， Haiming Wang

- Comparisons of error performance of the 4×4 system with BPSK Modulation and 1/2-rate and 1-ss.

QSTBC outperforms CSD by 0.5dB approximately.(PER=0.1)

doc.:11-14-1365-00-00aj

Submission

November 2014

Slide 12 Shiwen He ， Haiming Wang

- Comparisons of error performance of the 4×4 system with QPSK Modulation and 1/2-rate and 1-ss.

QSTBC outperforms CSD by 0.8dB approximately.(PER=0.1)

doc.:11-14-1365-00-00aj

Submission

November 2014

Slide 13 Shiwen He ， Haiming Wang

- Comparisons of error performance of the 4×4 system with 16QAM Modulation and 1/2-rate and 1-ss.

QSTBC outperforms CSD by 1.5dB approximately.(PER=0.1)

doc.:11-14-1365-00-00aj

Submission

November 2014

Slide 14 Shiwen He ， Haiming Wang

Conclusion

- As the system of conventional Alamouti’s code with 2 antennas, QOSTBC can obtain full rate transmission. And the performance of 802.11aj (45GHz) systems is apparently improved.

- Considering the implementation of hardware, the decoding algorithm of QOSTBC based on linear processing is simple, and all the signal processing can be performed on existing resources.

- It’s reasonable to apply QOSTBC to the systems of 802.11aj (45GHz).

doc.:11-14-1365-00-00aj

Submission

November 2014

Slide 15 Shiwen He ， Haiming Wang

Reference

[1] Single-Carrier Frequency-Domain Equalization for Space–Time Block-Coded Transmissions over Frequency-Selective Fading Channels[2] Single-Carrier Frequency-Domain Equalizer with Multi-Antenna Transmit Diversity[3] Frequency Domain DFE for Single-Carrier STBC Block Transmission[4] Coding for MIMO Communication Systems, Tolga M.Duman, Ali Ghrayeb

doc.:11-14-1365-00-00aj

Submission

November 2014

Slide 16 Shiwen He ， Haiming Wang

Thanks for Your Attention.

doc.:11-14-1365-00-00aj

Submission

November 2014

Slide 17 Shiwen He ， Haiming Wang

What is the performance comparison between STBC and

STBC combined with RF Beamforming?We would like to agree that the better performance can be obtained

when STBC is combined with RF Beamforming at the cost of the increase

of implementation complexity.

Questions & Replies