Title :
Maximal length sequences for QPSK
Author :
Komo, John J. ; Lam, Maurice S.
Author_Institution :
Dept. of Electr. & Comput. Eng., Clemson Univ., SC, USA
Abstract :
Nonbinary m-sequences are developed for direct use in QPSK. These quaternary maximal-length sequences, which can be directly assigned to the four phases of QPSK, are generated from primitive polynomials whose coefficients are in the Galois field of 2/sup 2/ elements (GF(2/sup 2/)). The autocorrelation function for the quaternary m-sequence is shown to be two-level and the crosscorrelation function for preferred pairs of these quaternary m-sequences is shown to be three- and four-level, similar to the binary cases. A class of quaternary Gold codes for use in spread-spectrum multiple-access communication is developed for sequences whose coefficients are in GF(2/sup 2/).<>
Keywords :
multi-access systems; phase shift keying; spread spectrum communication; Galois field; QPSK; autocorrelation function; crosscorrelation function; nonbinary m-sequences; quaternary Gold codes; quaternary maximal-length sequences; spread-spectrum multiple-access communication; Autocorrelation; Delay; Galois fields; Gold; Interleaved codes; Pain; Polynomials; Quadrature phase shift keying; Spread spectrum communication;
Conference_Titel :
System Theory, 1988., Proceedings of the Twentieth Southeastern Symposium on
Conference_Location :
Charlotte, NC, USA
Print_ISBN :
0-8186-0847-1
DOI :
10.1109/SSST.1988.17069
