This paper investigates a multihopping scheme for MFSK (Multilevel Frequency Shift Keying) /FH-SSMA (Frequency Hopping-Spread Spectrum Multiple Access) system. Moreover, we propose and investigate a modified decoding scheme for the coded MFSK/FH-SSMA system. In this multi-hopped MFSK/FH-SSMA system, several hopping frequencies per chip are assigned and transmitted in parallel in order to improve its frequency diversity capability for a fading channel. We theoretically analyze the performance of the multihopped MFSK/FH-SSMA system in a Rayleigh fading channel. Moreover, in the coded MFSK/FH-SSMA system, we propose a modified scheme of the error and erasure decoding of an error-correcting code. The modified decoding scheme utilizes the information of rows having the largest number of entries in the decoded time-frequency matrix. Their BER (Bit Error Rate) performance is evaluated by theoretical analysis in order to show the improvement in user capacity.