A New Scheme for Spreading & De-spreading in the Direct Sequence Spread Spectrum Mechanism

Direct Sequence Spread Spectrum (DSSS) and Frequency Hopping (FHSS) techniques are widely used to implement code-division multiple access (CDMA) in wireless communication systems. Both DSSS FHSS systems help reducing the effects of interference on transmitted information making it robust against channel impairments. uses a signal bandwidth that is much broader than bandwidth. Traditionally, wide band generated by multiplying narrowband with binary code, often designated as spreading generate wideband transmitted. The original can be recreated at receiver received same code (now de-spreading code) signal. To extract signal, codes must synchronism amplitude match each other. A new modification for direct sequence spread spectrum proposed this paper. mechanism introduced approach implicates generating circularly shifting (PN) n places, where represents value current byte yielded modulated using BPSK modulator before transmitting it. extracted correlating (which actually shifted places) locally replica code. position maximum cross-correlation vector byte. configuration has been implemented Simulink simulator obtained results show its performance identical conventional DSSS.