1st International ICST Workshop on Physics Inspired Paradigms for Wireless Communications and Network

Research Article

Randomness and metastability in CDMA paradigms

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  • @INPROCEEDINGS{10.4108/ICST.WIOPT2008.3232,
        author={Jack Raymond and David Saad},
        title={Randomness and metastability in CDMA paradigms},
        proceedings={1st International ICST Workshop on Physics Inspired Paradigms for Wireless Communications and Network},
        publisher={IEEE},
        proceedings_a={PHYSCOMNET},
        year={2008},
        month={8},
        keywords={AWGN Bandwidth Base stations Communication standards Decoding Metastasis Modulation coding Multiaccess communication Robustness Wireless communication},
        doi={10.4108/ICST.WIOPT2008.3232}
    }
    
  • Jack Raymond
    David Saad
    Year: 2008
    Randomness and metastability in CDMA paradigms
    PHYSCOMNET
    IEEE
    DOI: 10.4108/ICST.WIOPT2008.3232
Jack Raymond1,*, David Saad1
  • 1: Aston University, Neural Computing Research Group, Birmingham, B4 7ET, UK
*Contact email: raymonjr@aston.ac.uk

Abstract

Code Division Multiple Access (CDMA) in which the signature code assignment to users contains a random element has recently become a cornerstone of CDMA research. The random element in the construction is particularly attractive in that it provides robustness and flexibility in application, whilst not making significant sacrifices in terms of multiuser efficiency. We present results for sparse random codes of two types, with and without modulation. Simple microscopic consideration on system samples would suggest large differences in the phase space of the two models, but we demonstrate that the thermodynamic results and metastable states are equivalent. This may have consequences for developing algorithmic methods to escape metastable states, thus improving decoding performance.