<P> A method of achieving the spreading of a given signal is provided by the modulation scheme . With DSSS , the message signal is used to modulate a bit sequence known as a Pseudo Noise ( PN ) code ; this PN code consists of a radio pulse that is much shorter in duration ( larger bandwidth ) than the original message signal . This modulation of the message signal scrambles and spreads the pieces of data , and thereby resulting in a bandwidth size nearly identical to that of the PN sequence . In this context , the duration of the radio pulse for the PN code is referred to as the chip duration . The smaller this duration , the larger the bandwidth of the resulting DSSS signal ; more bandwidth multiplexed to the message signal results in better resistance against interference . </P>
<P> A method of achieving the spreading of a given signal is provided by the modulation scheme . With DSSS , the message signal is used to modulate a bit sequence known as a Pseudo Noise ( PN ) code ; this PN code consists of a radio pulse that is much shorter in duration ( larger bandwidth ) than the original message signal . This modulation of the message signal scrambles and spreads the pieces of data , and thereby resulting in a bandwidth size nearly identical to that of the PN sequence . In this context , the duration of the radio pulse for the PN code is referred to as the chip duration . The smaller this duration , the larger the bandwidth of the resulting DSSS signal ; more bandwidth multiplexed to the message signal results in better resistance against interference . </P>
which modulation scheme is preferred for dsss process
which modulation scheme is preferred for dsss process
Pseudo Noise ( PN ) code
Pseudo Noise ( PN ) code