My question is that could the use of cyclic prefix can enhance the performance of Rake receiver ?
I find this proposal here CP for DSSS Rake Receiver that seems correct.
The cost could be an overhead of transmission. But if I take a typical value of delay spread 5µs (ETU channel model) with UMTS SF = 256, the symbol duration is roughly SF/3.84Mcps = 256 / 3.84e6 = 66,66 µs. The cost 5/66.66 = 7.5% is acceptable ?
If the reason is not the overhead cost, is there any reason ? Or Rake receiver performance is not impacted by adding CP thanks to its pilots ?