Data Integrity and Combinatorics Research Unit

The work of this research unit is primarily concerned with the theory and applications of error-correcting codes and with applications of combinatorial mathematics, especially in radio system planning.

The work on codes includes:

  • Synchronisation of variable length codes
  • Constructions of constant weight codes
  • Codes for use in maximising the number of users and minimizing interference in code- division multiple-access radio systems and mobile telephone systems
  • DNA codes

A particular strength in recent years has been in applications of graph theory and meta-heuristic algorithms to frequency assignment in mobile telephone systems and other radio systems. Work on frequency assignment and coding theory reduces error rates resulting from noise and other sources of interference. Thus the work is of interest to users (both commercial and military) and developers of communication systems and data storage systems.

Good frequency assignments minimise interference and use valuable radio spectrum efficiently. This helps to mitigate the increasing demands on the limited amount of radio frequency available. Key successes in recent years have been the complete solution of the “Philadelphia” frequency assignment benchmarks, leading positions with respect to the “COST259” benchmarks, and the adoption by BAE Systems of methods and software developed in the unit in two major communication systems for the British Army.

The work has been supported by:

  • ComOpt AB and the former Radiocommunications Agency, now Ofcom (frequency assignment work).
  • EPSRC (frequency assignment and frequency hopping)
  • BAE Systems, QinetiQ (frequency assignment and coding theory in CDMA).