Research on performance of a T/F-domain MC-SS system over AWGN channels

Abstract

In this paper we research a time/frequency-domain multicarrier spread spectrum (T/F MC-SS) system combined with the time-domain spread spectrum and frequency-domain spread spectrum. The system could support multiuser and every user could parallel transmit multiple data bits. In the condition of synchronous transmission, we receive signals by using matched filter (MF), study the detection performance of single-user, simulate and analysis the performance of the bit-error ratio (BER) over additive white Gaussian noise (AWGN) channels. Our research shows that: for the same user, there exist no interference between different data bits which were parallel transmitted; the multiusers interference (MUI) only exist in the different data bits transmitted using the same subcarrier for different users and when the time-domain spreading codes assigned to different user are orthogonal there will exist no MUI; BER performance will become better along with the increase of spread spectrum gain and will become bad along with the increase of users number.