mhamed
Advanced Member level 4
Hi
As you know IEEE802.11b uses DSSS for its phy level. It uses 11-chip barker code. for 5.5Mbps mode, the modulation is BPSK. it means that without DSSS, it needs 5.5MHz bandwidth. using 11-chip Barker code increase the frequency to around 60.5MHz. but the bandwidth of the IEEE802.11b is 11Mhz (in baseband and 22MHz in RF frequency)!!! why?
As you know IEEE802.11b uses DSSS for its phy level. It uses 11-chip barker code. for 5.5Mbps mode, the modulation is BPSK. it means that without DSSS, it needs 5.5MHz bandwidth. using 11-chip Barker code increase the frequency to around 60.5MHz. but the bandwidth of the IEEE802.11b is 11Mhz (in baseband and 22MHz in RF frequency)!!! why?