IEICE Trans - On a Recent 4-Phase Sequence Design for CDMA

On a Recent 4-Phase Sequence Design for CDMA

A. Roger HAMMONS, Jr.  P. Vijay KUMAR

Publication
IEICE TRANSACTIONS on Communications   Vol.E76-B    No.8    pp.804-813
Publication Date: 1993/08/25
Online ISSN:
DOI:
Print ISSN: 0916-8516
Type of Manuscript: Special Section INVITED PAPER (Special Issue on Spread Spectrum Techniques and Applications)
Category:
Keyword:
pseudorandom sequences,  code-division multiple-access,  quadriphase sequences,

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Summary:
Recently, a family of 4-phase sequences (alphabet {1,j,-1,-j}) was discovered having the same size 2^r+1 and period 2^r-1 as the family of binary (i.e., {+1, -1}) Gold sequences, but whose maximum nontrivial correlation is smaller by a factor of

2. In addition, the worst-case correlation magnitude remains the same for r odd or even, unlike in the case of Gold sequences. The family is asymptotically optimal with respect to the Welch lower bound on C_max for complex-valued sequences and the sequences within the family are easily generated using shift registers. This paper aims to provide a more accessible description of these sequences.