Generalized d-sequences and their applications to CDMA systems
Radhika Vaddiraja · 2003
Code Division Multiple Access (CDMA), a form of spread spectrum communications is used widely in cellular telephony. CDMA systems employ Walsh-Hadamard orthogonal codes, jointly with Pseudo-Noise (PN) sequences, Gold sequences and Kasami sequences to achieve spreading. This thesis investigates properties of generalized d-sequences and their applications as spreading sequences in CDMA systems. The correlation properties of these sequences are studied. The autocorrelation function of these sequences is not exactly two-valued but the cross correlation values are zero for certain class of these sequences. The zero cross correlation property can be useful in solving the near-far problem in CDMA communication systems, thus obviating the need for power control. The performance of these sequences is analyzed and their application to CDMA systems is investigated.