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The performance of robust adaptive modulation over wireless channels with non reciprocal interference

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Original languageEnglish
Title of host publicationIEEE 55th Vehicular Technology Conference, 2002 (VTC Spring 2002)
Publisher or commissioning bodyInstitute of Electrical and Electronics Engineers (IEEE)
Pages1497 - 1501
Number of pages5
ISBN (Print)0780374843
StatePublished - May 2002
Event55th Vehicular Technology Conference 2002 (VTC 2002-Spring) - Birmingham, Ala., United States


Conference55th Vehicular Technology Conference 2002 (VTC 2002-Spring)
CountryUnited States
CityBirmingham, Ala.
Period1/05/02 → …


Adapting a modem's modulation scheme can significantly enhance the resulting performance over a wireless communications link. Non-adaptive modems are generally designed conservatively for worst-case channel conditions. Adaptive modems are able to exploit the higher channel capacity when good conditions are encountered. A number of different metrics can be used to drive the adaptation process (i.e. automatic repeat request (ARQ) or segment error rate (SER)). Not surprisingly, certain metrics are far more successful than others. This paper presents an investigation of adaptive modulation in the presence of interference. In particular, the case of non reciprocal interference is studied (i.e., cases where the level of interference is different on the forward and reverse links). Research results have shown that if adaptation is performed assuming a reciprocal channel, then poor performance will result for the link experiencing a higher level of interference. In this study, an algorithm is used to calculate a measure of the link quality. This value is then fed back to the other end of the link to adapt subsequent transmissions. Results indicate that the throughput of such a system can be considerably improved when transmitting adaptively using any one of DBPSK, DQPSK or 8DPSK modulation schemes. It is proposed that this simple approach be adopted for short range, ad hoc, wireless personal area networks (WPAN)

Additional information

Rose publication type: Conference contribution Sponsorship: The authors gratefully acknowledge the directors of Toshiba Research Europe Limited, Telecommunications Research Laboratory for their support and the permission to publish this work Terms of use: Copyright © 2002 IEEE. Reprinted from Proceedings of IEEE 55th Vehicular Technology Conference, Spring-2002. This material is posted here with permission of the IEEE. Such permission of the IEEE does not in any way imply IEEE endorsement of any of the University of Bristol's products or services. Internal or personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution must be obtained from the IEEE by writing to By choosing to view this document, you agree to all provisions of the copyright laws protecting it Contributor (Other): Institute of Electrical and Electronics Engineers (IEEE)


55th Vehicular Technology Conference 2002 (VTC 2002-Spring)

Duration1 May 2002 → …
CityBirmingham, Ala.
CountryUnited States

Event: Conference

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