| EPSRC Reference: |
GR/K27902/01 |
| Title: |
SPECTRALLY EFFICIENT DIGITAL RADIO SCHEME INTEGRATED SERVICES PERSONAL COMMUNICATIONS SYSTEMS-FEASI STUDY |
| Principal Investigator: |
Ormondroyd, Professor R |
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| Department: |
Electronic and Electrical Engineering |
| Organisation: |
University of Bath |
| Scheme: |
Standard Research (Pre-FEC) |
| Starts: |
01 April 1995 |
Ends: |
30 September 1997 |
Value (£): |
89,384
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| EPSRC Research Topic Classifications: |
| Digital Signal Processing |
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Summary on Grant Application Form |
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Coded orthogonal frequency division multiplexing (COFDM) is a robust modulation technique developed for high quality broadcast radio in a mobile environment. The broad aim of the research is to develop a multiple-access variant of COFDM (MA-COFDM) capable of outperforming CDMA and TDMA digital cellular radio systems in a fading environment when providing broadband digital services to mobile subscribers. Key elements of the work are:(i) the trade-off between the number of simultaneous users supported and the ability of the system to resist multipath fading for different MA-COFDM strategies,(ii) the optimum coding strategies for assignment of subscribers,(iii) the influence of the network access protocol on packet throughput,(iv) the resilience of the system to co-channel and adjacent channel interference,(v) the feasibility of efficient ATM packet transfer over the radio interface.Progress:There has been a delay of six months in the start of this project because we have been unable to appoint a suitably qualified research assistant. However, as a result of interviews which were held recently, we are hopeful that an appointment will be made with effect from 1st April 1995. The necessary workstation and simulation software have been ordered and we are awaiting delivery of these items.Despite not being able to appoint an RA, considerable progress has been made on the project and two papers have been submitted to international conferences recently as a result of this early work. Using computer simulations written in PASCAL and C we have made a preliminary study of the importance of convolutional coding on the capacity of CDMA cellular radio systems. The original basis for this was to provide a benchmark against which the MA-COFDM system could be compared. However, this has led to new work on high performance CDMA systems based on orthogonal low-rate convolutional codes rather than the more traditional direct-sequence CDMA systems. The effect of hard and soft decision Viterbi decoders on the capacity of cellular radio systems based on this approach has been studied. Preliminary results [1] indicate that there are useful gains in capacity to be achieved by this new method. COFDM is extremely resilient to multipath fading and it is feasible that it would be an effective method of transmitting ATM packets over the radio interface. In this case the radio necessary to maximise the base station data throughput under these circumstances. The work submitted in [2], details an interesting method of maximising packet throughput of continuous and bursty traffic at a switch by means of dynamic packet prioritisation based on packet dropping of the continuous data. Both these areas of work are ongoing. 1.R.F. Ormondroyd and J.J. Maxey: A high performance CDMA cellular radio system based on orthogonal low-rate convolutional coding ,Submitted to the IEE International Conference on Radio Receivers and Associated Systems, September 1995 2.R.F. Ormondroyd and S.M. Walker: A Throughput Dependent Priority Discipline for a Multi-class Traffic Packet Switch - a simulation study ,Submitted to the IEEE Military Communications Conference (MILCOM '95). San Diego. November 1995
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Potential use in non-academic contexts |
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Impacts |
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| Description |
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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.bath.ac.uk |