Optimizing performance of multiple access multi-carrier multilevel frequency shift keying systems

Abstract

We present the optimization of the multiple-access Multi-carrier Multilevel Frequency Shift Keying (MC-MFSK) system. In MC-MFSK systems, each user is allocated a permutation of frequency carriers to simultaneously transmit a symbol. We optimize the system with respect to the diversity order, which is the number of frequency-carriers, and the modulation level. We derive an analytical solution on the optimal diversity order for maximum throughput. We also derive optimal solutions for the system where control of the diversity orders is distributed to the users, and where the allocation of frequency-carriers is based on a combinatorial construction, called Balanced Incomplete Block design. We extend our result to the Frequency-Hopping Multi-carrier (FHMC) MFSK system by introducing additional frequency-hopping to the MC-MFSK system. Our newly derived formulas are used to compute and analyze the maximum capability of the MC-MFSK system and show that the MC-MFSK system is a strong candidate for future spread-spectrum systems.