DocumentCode :
3753465
Title :
Time Localization and Capacity of Faster-Than-Nyquist Signaling
Author :
Ather Gattami;Emil Ringh;Johan Karlsson
Author_Institution :
Bitynamics Res., Stockholm, Sweden
fYear :
2015
Firstpage :
1
Lastpage :
7
Abstract :
In this paper, we consider communication over the bandwidth limited analog white Gaussian noise channel using non-orthogonal pulses. In particular, we consider non-orthogonal transmission by signaling samples at a rate higher than the Nyquist rate. Using the faster-than- Nyquist (FTN) framework, Mazo showed that one may transmit symbols carried by sinc pulses at a higher rate than that dictated by Nyquist without loosing bit error rate. However, as we will show in this paper, such pulses are not necessarily well localized in time. In fact, assuming that signals in the FTN framework are well localized in time, one can construct a signaling scheme that violates the Shannon capacity bound. We also show directly that FTN signals are in general not well localized in time. We also consider FTN signaling in the case of pulses that are different from the sinc pulses. We show that one may use a precoding scheme of low complexity, in order to remove the intersymbol interference. This leads to the possibility of increasing the number of transmitted samples per time unit and compensate for spectral inefficiency due to signaling at the Nyquist rate of the non sinc pulses. We demonstrate the power of the precoding scheme by simulations.
Keywords :
"Interference","Electronic mail","Complexity theory","Fourier transforms","Bandwidth","Bit error rate"
Publisher :
ieee
Conference_Titel :
Global Communications Conference (GLOBECOM), 2015 IEEE
Type :
conf
DOI :
10.1109/GLOCOM.2015.7417358
Filename :
7417358
Link To Document :
بازگشت