SC-FDMA is a modified form of OFDM
with similar throughput performance and complexity. This is often viewed as DFT-coded
OFDM where time-domain data symbols are transformed to frequency-domain by a discrete Fourier transform (DFT) before going through the standard OFDM modulation стр. 4
It is evident from the figures that SC-FDMA transceiver
has similar structure as a typical OFDM system except the addition of a new DFT block
before subcarrier mapping. Hence, SC-FDMA can be considered as an OFDM system with
a DFT mapper. стр. 9
As each data symbol is spread
over multiple subcarriers, SC-FDMA offers spreading gain or frequency diversity gain in a
frequency selective channel. Thus, SC-FDMA can be viewed as frequency-spread OFDMor
DFT-spread OFDM стр. 11
For some of the subcarrier
mappings, the time domain representation of the IFFT output, as shown in Figures 8 and
9, will give more insight on the SC-FDMA signal стр. 13 - обратите внимание, для некоторых вариантов маппирования поднесущих
Цитата
И не путайте боковые лепестки с фазовыми шумами.
Размазывание энергии на соседнии поднесущие происходит только при сшивании сигнала во времянной области - разве это называется не фазовыми шумами?
Выношу SC-FDMA в отдельную тему, Кто что скажет?
Jul 2 2013, 20:02
