Title :
Spectral shaping codes
Author :
Waldman, Helio ; Pingarilho, Carlos A M
Author_Institution :
DECOM/FEE/UNICAMP, Sao Paolo, Brazil
fDate :
27 Jun-1 Jul 1994
Abstract :
A finite-state constraint is proposed for the construction of binary codes with wide spectral notches in the spectrum of PAM signals. Spectral notches at DC are obtained by requiring that all sub-strings with length N of the PAM sequence have disparity magnitude at most d: this is called the (d,N)-constraint. The constraint is investigated for its Shannon capacity and number of states. A special enhancement of the constraint is found to reinforce the spectral features with only a small loss in capacity. Sliding-block codes are obtained for (d,N)=(1,5) for a few efficient rates, and their spectra are calculated and compared
Keywords :
binary sequences; block codes; pulse amplitude modulation; spectral analysis; PAM sequence; PAM signals; Shannon capacity; binary codes; code rates; disparity magnitude; finite-state constraint; sliding-block codes; spectral shaping codes; sub-strings; wide spectral notches; Binary codes; Decoding; Frequency; H infinity control; Passband; Shape;
Conference_Titel :
Information Theory, 1994. Proceedings., 1994 IEEE International Symposium on
Conference_Location :
Trondheim
Print_ISBN :
0-7803-2015-8
DOI :
10.1109/ISIT.1994.394759
