1. STBC in Single Carrier(SC) for IEEE 802.11aj (45GHz)
Date:
Presenter: Shiwen HE
Authors/contributors:
Shiwen He, Haiming Wang

2. Abstract
Propose an Alamouti-like scheme combining space-time block coding with single-carrier frequency-domain equalization for IEEE aj (45GHz).
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Shiwen He, Haiming Wang

3. Background
The primary challenge in wireless block transmission systems is the time dispersive nature of the multipath fading channel, which can cause severe intersymbol interference (ISI), resulting in an inevitable system performance deterioration.
Alamouti’s space–time block coding (STBC) scheme has been proposed in IEEE n and IEEE ac since
it achieves full spatial diversity at full transmission rate for 2 transmit antennas and any signal constellation.
it does not require channel state information at the transmitter.
maximum likelihood decoding of STBC requires only simple linear processing.
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Shiwen He, Haiming Wang

4. Background cont.
In IEEE n and IEEE ac, STBC is used with OFDM. Compared with OFDM, Single Carrier –Frequency Domain Equalization(SC-FDE) has similar implementation complexity and performance, while avoiding the major drawbacks of OFDM, including high peak-to-average power ratio and sensitivity to carrier frequency offset.
This submission proposes the STBC scheme in SC for IEEE aj.
Shiwen He, Haiming Wang

5. Scheme: Tx2 Rx1 Block format for proposed STBC transmission scheme.
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Shiwen He, Haiming Wang

6. Scheme: Tx2 Rx1
The stream of block complex numbers , , is the input to the STBC encoder, which produces as output the stream of complex numbers , , For given , STBC processing operates on the complex modulation symbols as follows:
where , ,
Note：the transmitted power from each antenna is half its value in the single-transmit case so that total transmitted power is fixed.
Shiwen He, Haiming Wang

7. Scheme:Tx4 Rx2 or Tx4 Rx4
Block format for proposed STBC transmission scheme(2 space streams).
1st space stream
2nd space stream
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Shiwen He, Haiming Wang

8. Constellation mapper output to spatial mapper input for STBC
is th transmitted block from space stream , is the output of STBC encoder，
where , ,
Shiwen He, Haimin Wang

9. Simulation
Comparisons of error performance of the 2x1 system(1 space stream) with BPSK Modulation and 1/2-rate.
1.4dB gain
CSD
STBC
Shiwen He, Haiming Wang

10. Simulation
Comparisons of error performance of the 2x1 system(1 space stream) with QPSK Modulation and 1/2-rate. .
1.7dB gain
STBC
CSD
Shiwen He, Haiming Wang

11. Simulation
Comparisons of error performance of the 2x1 system(1 space stream) with 16-QAM Modulation and 1/2-rate.
1.8dB gain
Shiwen He, Haiming Wang

12. Simulation
Comparisons of error performance of the 4x2 system and 2x2 system with 1/2-rate and 2 space streams.
Shiwen He, Haiming Wang

13. Simulation
Comparisons of error performance of the 4x4 system and 2x4 system with 1/2-rate and 2 space streams.
Shiwen He, Haiming Wang

14. Conclusion
The proposed single-carrier transmit-diversity scheme for frequency-selective channels is low-complexity
The scheme combines the advantages of an Alamouti-like space–time block-coding scheme and FFT-based single-carrier frequency-domain equalization.
The scheme can be particularly useful in order to achieve transmit diversity when signalling with higher order constellations (e.g. 16QAM) as the complexity of the equalization is not increased.
Significant performance gains over transmission without STBC were demonstrated for IEEE aj.
Shiwen He, Haiming Wang

15. References [1] IEEE 802.11n,IEEE 802.11ac
[2] N. Al-Dhahir, “Single-Carrier Frequency-Domain Equalization for Space Time Block-Coded Transmissions Over Frequency-Selective Fading Channels,” IEEE Commun. Lett., vol. 5, no. 7, July 2001.
[3] Q. Wang, C. Yuan, J. Zhang, Z. Hu, and Y. Li, “Frequency Domain DFE for Single-Carrier STBC Block Transmission,” IEEE Commun. Lett., vol.17, no. 6, June 2013.
[4] D. Falconer, S. Ariyavisitakul, A. Benyamin-Seeyar, and B. Eidson, “Frequency domain equalization for single-carrier broadband wireless systems,” IEEE Commun. Mag., vol. 40, no. 4, pp. 58C66, Apr
Shiwen He, Haiming Wang

16. Thanks for Your Attention.
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Shiwen He, Haiming Wang