Multi-Subchannel Spread Spectrum Modulation

A new spread spectrum technique called Multi-Subchannel Spread Spectrum Modulation (MSCSSM) is proposed. The system basically consists of the superposition of M different direct sequence (DS) spread spectrum systems having different carrier frequencies. Main feature of the proposed system is that the spreading bandwidth and hence the processing gain can be increased, without a need for increasing the spreading code sequence rate, by increasing the number of subchannels used. Bit error performance of MSCSSM system in the presence of additive white Gaussian noise and interference from other similar transmitters or CW tone jamming is analysed. For both of the above mentioned types of interference, the MSCSSM system is shown to have a performance advantage over a DS spread spectrum system utilizing the same spreading bandwidth to data bit rate ratio.