Comunicacions d'espectre eixamplat 4 Ionosfera 4 Radiofreqüència 4 Tesis 4 Guies d'ones 2 Ones de ràdio 2 Propagació 2 Digital communications 1 Direct Sequence Spread Spectrum 1 Direct-Sequence Spread Spectrum (DSSS) 1 Doppler spread 1 High Frequency 1 High Frequency (HF) 1 Hostile Channel 1 Ionosphere 1 Ionospheric Communications 1 Multipath spread 1 Orthogonal Frequency Division Multiplexing 1 Orthogonal Frequency Division Multiplexing (OFDM) 1 Signal to Noise Ratio 1 Single Carrier Frequency Division Multiplexing Access (SC-FDMA) 1 Single Carrier Frequency Domain Equalization (SC-FDE) 1 Sky-wave propagation 1 Sounding 1