Advanced Research and EAdvanced Research and …...Title: Microsoft PowerPoint - 06.7-001 Kreb Author: Allan Margulies Created Date: 10/19/2004 5:30:38 AM

Advanced Research and Engineering Solutions (ARES)AAdvanced RResearch and EEngineering SSolutions (ARES)

Asymmetric Modulationfor Cognitive Radio andIntelligent Environments

2004 Software Defined RadioTechnical Conference and Product Exposition

Eric KrebScientific Applications International [email protected]

Robert Morelos-ZaragozaSan Jose State [email protected]

Proceeding of the SDR 04 Technical Conference and Product Exposition. Copyright © 2004 SDR Forum. All Rights Reserved

11/18/2004 2


Outline

• Introduction• Asymmetric Modulation

– Design– Mathematical Analysis– Graphical Analysis

• Asymmetric Coherence• Opportunities for Intelligent Environments• Conclusion


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Complex Baseband System Model


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Orthogonal Basis Functions

∫Tdt

0

∫Tdt

0

∫Tdt

0

1φ

2φ

Nφ

1is

2is

iNs

is

1φ

2φ

Nφ

1is

2is

iNs

is

)(tsI

)(tsQ

)(ts)(ts

)(tsI

)(tsQ

)2(1 tfCOS cπφ =

2φ

)2(1 tfCOS cπφ =

2φ


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Common Modulation Schemes

Constant Envelope Modulated Envelope


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Asymmetric Modulation Design

AsPSKAsymmetric Phase-Shift Keying

AsQAMAsymmetric Quadrature Amplitude Modulation


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Asymmetric Phase-Shift Keying

Mapping Functions

11 2)1( παα +−= xy )1( 22)2( ααπ −= xy


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AsPSK: Constellations


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AsPSK: Expected BER in AWGN

( ) ( )

−−⋅

⋅⋅⋅≈M

MNEMQP B

bαπ 1sinlg2

01

( )( )

−

⋅⋅⋅≈−α

π1

02

1sinlg2MM

NEMQP B

b

AsPSK- 1 & AsPSK- 2


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AsPSK: Dynamic Control


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AsQAM: Lattice Structure

QAM vs AsQAM


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AsQAM: Lattice Structures

Direct Comparisonof

Square Lattice & Simplex Lattice


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AsQAM: Constellations


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AsQAM: BER in AWGN

≈

0_ 5

243

NEQP B

QAMb

≈

0_ 3

22NEQP B

AsQAMb

QAM & AsQAM


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AsQAM vs. Standard QAM

Nearest-Neighbor Distances

0.632516-QAM

0.66594

0.66903

0.66882

0.67611

16-AsQAM- 1


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Clock Synchronization


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Coherent & NoncoherentReceivers


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Detector Simulations

AsPSK- 1 AsPSK- 2


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Opportunities forIntelligent Environments

• Dynamic Design

• Synchronization and Data Transfer Modes

• Low Priority Data Transfer at Low Cost

• Continuous and Discrete Constellation Monitoring


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Conclusion

• Discrete and Continuous Dynamic Designs

• Optimal Lattice Structure

• Asymmetric Coherence

• Environmental Intelligence Capability


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References

[1] S. Haykin, Communication Systems, 4th ed., New York: Wiley, 2001

[2] M. Isaka, M. Fossorier, R. Morelos-Zaragoza, S. Lin, H. Imai, “Multilevel Coded Modulation for Unequal Error Protection and Multistage Decoding – Part II: Asymmetric Constellations,” IEEE Transactions on Communications, no. 5, pp. 774-786, May 2000

[3] L. Venkata Subramaniam, S. Rajan, R. Bahl, “Performance of 4- and 8-State TCM Schemes with Asymmetric 8-PSK in Fading Channels,” IEEE Transactions on Vehicular Technology, vol. 49, No. 1, pg 211-219, January 2000

[4] F. Sanzi, M. C. Necker, “Totally Blind APP Channel Estimation with Higher Order Modulation Schemes,” Proceedings of the Vehicular Technology Conference, Orlando, October 2003

[5] G. Colavope, R. Raheli, “On Noncoherent Sequence Detection of Coded QAM,”IEEE Communications Letters, Vol. 2, No. 8, August 1998


Advanced Research and EAdvanced Research and …...Title: Microsoft PowerPoint - 06.7-001 Kreb Author: Allan Margulies Created Date: 10/19/2004 5:30:38 AM

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