Open AccessBlind Hopping Phase Estimator in Frequency‐Hopped FM and BFSK Systems
Author(s) -
Kim Myungsup,
Seong Jinsuk,
Lee SeongRo
Publication year - 2015
Publication title -
etri journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.295
H-Index - 46
eISSN - 2233-7326
pISSN - 1225-6463
DOI - 10.4218/etrij.15.0114.0809
Subject(s) - frequency hopping spread spectrum , demodulation , frequency shift keying , cramér–rao bound , frequency modulation , estimator , amplitude and phase shift keying , spread spectrum , mathematics , frequency deviation , algorithm , electronic engineering , bandwidth (computing) , phase shift keying , telecommunications , computer science , statistics , bit error rate , engineering , automatic frequency control , channel (broadcasting) , decoding methods , code division multiple access
A blind hopping phase estimator is proposed for the demodulation of received signals in frequency‐hopping spread spectrum systems. The received signals are assumed to be bandwidth limited with a shaping filter, modulated as frequency modulation (FM) or binary frequency shift keying (BFSK), and hopped by predetermined random frequency sequences. In the demodulation procedure in this paper, the hopping frequency tracking is accomplished by choosing a frequency component with maximum amplitude after taking a discrete Fourier transform, and the hopping phase estimator performs the conjugated product of two consecutive signals and moving‐average filtering. The probability density function and Cramer‐Rao low bound (CRLB) of the proposed estimator are evaluated. The proposed scheme not only is very simple to implement but also performs close to the CRLB in demodulating hopped FM/BFSK signals.