Here at http://direct-sequence.blogspot.co.uk/ you'll find the blog for our year 2 project blog titled " Direct -Sequence Spread Spectrum for 3G Mobile communication ", by Altynay Kaidarova and Jiang Zhengiivang, supervised by Dr. X ZHU.
PeoPeople have developed a strong necessity for accessing the high-speed, secure and reliable Internet . The most popular approach of implementation 3G communication is DS-SS. DS-SS( or DS-CDMA), is spread spectrum modulation method designed for digital signal transmission. It uses pseudorandom noise sequence as a modulation waveform in order to transmit and spread the energy of the signal over much greater bandwidth than the bandwidth of the signal information. This results in many benefits, such as immunity to interference ,jamming and multi-user access of the same channel. In this project the implementation of the DSSS was achieved by using MATLAB. The aim is to investigate the procedure of the spreading and dispreading of the direct-sequence spread spectrum , the relationship between SNR & BER for few users, the relationship of SNR with BER for different spreading gain. The essential and key aspect of the project is to generate the pn sequence using one of the available methods. Sufficient usage of transmitter power and channel bandwidth is therefore investigated.
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