<Ul> <Li> </Li> <Li> </Li> <Li> </Li> </Ul> <P> In telecommunications, direct - sequence spread spectrum (DSSS) is a spread spectrum modulation technique used to reduce overall signal interference . The spreading of this signal makes the resulting wideband channel more noisy, allowing for greater resistance to unintentional and intentional 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> <P> Some practical and effective uses of DSSS include the Code Division Multiple Access (CDMA) channel access method and the IEEE 802.11 b specification used in Wi - Fi networks . </P>

Which modulation scheme is preferred for dsss process