Bandwidth Efficient MT-DS-SS via Reduced Subcarrier Frequency Spacing

Document Type


Subject Area(s)

Electrical and Computer Engineering


We investigate modifications to conventional multitone direct-sequence spread spectrum (MT-DS-SS) signaling to improve spectral efficiency, for high-data-rate systems with small processing gain. Reduction in subcarrier frequency spacing to half the symbol rate improves bandwidth efficiency at no cost in complexity or performance. Via both analysis and simulations, we provide example results that illustrate the attractive performance and throughputs attainable with reduced frequency spacing. We extend study to synchronous multiuser transmission, and show that our best spectrally efficient MT-DS-SS scheme outperforms the conventional MT-DS-SS in a dispersive multiuser environment.