Frequency-hopping spread-spectrum (FH-SS) is an efficient technique to combat jamming. Previous works in jamming channels pay more attention to partial band noise jamming (PBNJ). In this paper, Low-Density Parity-Check (LDPC) coded fast frequency hopping binary frequency shift keying (FFH/BFSK) spread-spectrum (SS) systems are investigated under band multitone noise jamming (BMTJ). We take the advantage of both diversity gain and coding gain for enhancing the system performance. We consider maximum-likelihood (ML) diversity combing and square-law with equal gain combing schemes which are used to compute the codeword bit decision reliability. The sum-product algorithm (SPA) based on belief propagation is exploited for iterative decoding. Simulation results reveal that our proposed system provides excellent performance against band multitone noise jamming.