rfsystem
Advanced Member level 3
The guard carriers seems to be useless to me!
1. ISI and symbol timing inaccuracy tolerance is implemented by the cyclic symbol extension.
2. Channel separation is done by possible/certain oversampled filtering after analog filtering.
3. Channel separation in WiMAX is today less than the symbol sampling frequency.
But there are strong reasons to have a 2^k usage of all subcarriers
1. There are better, less PAPR, preamables avaible for 2^k
2. Channel segmentation could be done on binary trees
Is the guard an ugly historical reason? Or am I missing something?
1. ISI and symbol timing inaccuracy tolerance is implemented by the cyclic symbol extension.
2. Channel separation is done by possible/certain oversampled filtering after analog filtering.
3. Channel separation in WiMAX is today less than the symbol sampling frequency.
But there are strong reasons to have a 2^k usage of all subcarriers
1. There are better, less PAPR, preamables avaible for 2^k
2. Channel segmentation could be done on binary trees
Is the guard an ugly historical reason? Or am I missing something?