In telecommunications, direct-sequence spread spectrum (DSSS) is a spread-spectrum modulation technique primarily used to reduce overall signal interference.
After the despreading or removal of the direct-sequence modulation in the receiver, the information bandwidth is restored, while the unintentional and intentional interference is substantially reduced.
Each element of the spreading sequence, a so-called chip, has a shorter duration than the original message symbols.
[1][3] Some practical and effective uses of DSSS include the code-division multiple access (CDMA) method, the IEEE 802.11b specification used in Wi-Fi networks, and the Global Positioning System.
If an undesired transmitter transmits on the same channel but with a different spreading sequence, the despreading process reduces the power of that signal.