Quaternary Constant-Amplitude Codes for Multicode CDMA
<|reference_start|>Quaternary Constant-Amplitude Codes for Multicode CDMA: A constant-amplitude code is a code that reduces the peak-to-average power ratio (PAPR) in multicode code-division multiple access (MC-CDMA) systems to the favorable value 1. In this paper quaternary constant-amplitude codes (codes over Z_4) of length 2^m with error-correction capabilities are studied. These codes exist for every positive integer m, while binary constant-amplitude codes cannot exist if m is odd. Every word of such a code corresponds to a function from the binary m-tuples to Z_4 having the bent property, i.e., its Fourier transform has magnitudes 2^{m/2}. Several constructions of such functions are presented, which are exploited in connection with algebraic codes over Z_4 (in particular quaternary Reed-Muller, Kerdock, and Delsarte-Goethals codes) to construct families of quaternary constant-amplitude codes. Mappings from binary to quaternary constant-amplitude codes are presented as well.<|reference_end|>
@article{schmidt2006quaternary,
    title={Quaternary Constant-Amplitude Codes for Multicode CDMA},
    author={Kai-Uwe Schmidt},
    journal={IEEE Trans. Inf. Theory, vol. 55, no. 4, pp. 1824-1832, April 2009},
    year={2006},
    archivePrefix={arXiv},
    eprint={cs/0611162},
    primaryClass={cs.IT math.IT}
}