This paper presents a novel anti-jamming wireless communication system called Multi-Subchannel Spread Spectrum (MSCSS). It is based on M-ary spread spectrum (SS), direct sequence spread spectrum (DS-SS), orthogonal frequency division multiplexing (OFDM), and multi-carrier code division multiple access (MC-CDMA). The signal is spread twice at the MSCSS transmitter using a channel pseudo-random code and a subchannel pseudo-random code. Each information bit is transmitted in time-division mode on 16 subchannels, and the pseudo-random codes over the subchannels are mutually orthogonal. At the receiver, an adaptive decision threshold is employed which provides improved anti-jamming performance.