Performance of scale-time-code division multiple access over the synchronous AWGN channel

Abstract

Recently, we have proposed a new multiple access system called scale-time-code division multiple access (STCDMA) which depends on the code, and time and scale orthogonality introduced by pseudo-noise (PN) sequences, and wavelets. We use wavelets as an orthonormal set of symbols for signaling, and exploit their orthonormality over scale and time. In a STCDMA system, the channel is partitioned into different scales, and each scale into different time slots. In addition, direct-sequence (DS) code division multiple access (CDMA) is used in each time slot to identify multiple users. We analyse the performance of a STCDMA system communicating with dyadically scaled Haar wavelets and antipodal signaling over a synchronous additive white Gaussian noise (AWGN) channel by using a conventional detector for each user. We show that STCDMA supports many more users than conventional DS-CDMA for the same binary phase-shift-keying (BPSK) performance and bandwidth occupancy when complex-valued Hadamard PN sequences and Kronecker PN sequences formed by the Kronecker product of complex-valued Hadamard PN sequences and real-valued Gold PN sequences are used. Copyright (C) 2000 John Wiley & Sons, Ltd.