| EPSRC Reference: |
GR/J70062/01 |
| Title: |
MULTI-CARRIER TRANSMISSION SCHEME FOR WIRELESS LANS |
| Principal Investigator: |
Barton, Professor S |
| Other Investigators: |
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| Project Partners: |
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| Department: |
Electronic & Electrical Engineering |
| Organisation: |
University of Bradford |
| Scheme: |
Standard Research (Pre-FEC) |
| Starts: |
25 July 1994 |
Ends: |
24 July 1996 |
Value (£): |
141,975
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| EPSRC Research Topic Classifications: |
| RF & Microwave Technology |
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Summary on Grant Application Form |
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Investigate effects of controlling Peak Envelope Power digitally in a multi-carrier transmission scheme. Investigate amplifier linearisation schemes for the battery powered portable computer. Investigate demodulator architectures based on the Winograd FFT algorithm. Investigate coding and spectral interleaving strategies.Progress:An intensive investigation of the relationship between Peak Envelope Power and Message bits for Multicarrier QPSK transmission systems has been conducted with the objective of ascertaining both the Peak Factor Distribution and possible message coding schemes which would enable the Peak Factor to be reduced.The first phase of this work addressed the problem of determining the mathematical relationship between the peak factor (Ratio of the Peak Envelope Power to the Mean Power) for an N carrier QPSK transmission scheme with 2N uncoded message bits. It was realised at an early stage that an exhaustive evaluation of the Peak Factors for the 22N possible messages constituting the message space is not sensible for N>8 and considerable effort was applied to determining any mathematical structure (possibly a Group structure), which would enable the computational burden to be reduced. The primary result of this investigation is that the message space of dimension 22N, may be split into 22N-4 cosets formed from 16 messages each having the same peak factor and that each coset may be simply generated from its coset leader, whose first four bits are zero. The results of this work are presented in detail in [1]. In the second phase the coding problem was addressed. The initial effort was applied to a 4 carrier QPSK transmission scheme where the first four bits are taken as message bits and the second four bits are coding bits. It was readily established that the four coding bits which achieve the lowest possible peak factor for each message are directly related to the four message bits and that the relationship may be implemented using combinatorial logic. This half rate coding scheme is readily extended to 4N carrier QPSK transmission schemes by having every four message bits followed by four coding bits and the results of this work are presented in [2]. 1 The Distribution of Peak Factory in QPSK Multicarrier Modulation. Journal of Wireless Personal Communications. Kluwer. Submitted 15. 12. 94. 2 A Simple Coding scheme to reduce Peak Factor in QPSK Multicarrier Modulation. Electronics Letters submitted 5. 2. 95.
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Key Findings |
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This information can now be found on Gateway to Research (GtR) http://gtr.rcuk.ac.uk
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Potential use in non-academic contexts |
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This information can now be found on Gateway to Research (GtR) http://gtr.rcuk.ac.uk
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Impacts |
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| Description |
This information can now be found on Gateway to Research (GtR) http://gtr.rcuk.ac.uk |
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Sectors submitted by the Researcher |
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This information can now be found on Gateway to Research (GtR) http://gtr.rcuk.ac.uk
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| Project URL: |
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| Further Information: |
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| Organisation Website: |
http://www.brad.ac.uk |