Direct Sequence Spread Spectrum - Siemens IEEE802.11 Tutorial

Direct Sequence Spread Spectrum

RF Energy is Spread by XOR of Data with PRN Sequence
1
1 bit period
11 Bit Barker Code (PRN*)
1011011100010110111000
11 chips
* PRN: Pseudorandom Number
Transmitter baseband signal before spreading
Transmitter baseband signal after spreading
,
0
Data
PRN
Signal
Spectrum
0100100011110110111000
Out
11 chips
Receiver baseband signal before matched filter (Correlator)
Receiver baseband signal after matched filter (De-spread)
1 bit
period
© Siemens, 2002