Title :
A fully digital feedforward MSK demodulator with joint frequency offset and symbol timing estimation for burst mode mobile radio
Author :
Mehlan, R. ; Chen, Yong-En ; Meyr, Heinrich
Author_Institution :
Aachen Univ. of Technol., Germany
fDate :
11/1/1993 12:00:00 AM
Abstract :
A strictly feedforward demodulator structure for minimum shift keying (MSK) modulation with joint nondata-aided symbol clock and frequency offset estimation is presented. Due to its feedforward operation, clock synchronization and frequency offset compensation are hang-up free, and the demodulator is well suited for a digital implementation. The sampled baseband signal is passed through a nonlinearity and smoothed by a digital filter. The magnitude of the filter output directly drives the clock recovery process. The phase of the smoothed signal is an estimate of the carrier frequency offset and is used for offset compensation. Following synchronization, the signal is demodulated by differentially coherent detection. The performance of the demodulator is assessed for the AWGN and the Rayleigh flat and frequency-selective fading channel by computer simulations
Keywords :
demodulators; digital filters; fading; minimum shift keying; mobile radio systems; synchronisation; telecommunication channels; AWGN channel; MSK; Rayleigh fading channel; burst mode mobile radio; clock recovery process; clock synchronization; differentially coherent demodulation; digital filter; feedforward demodulator; flat fading channel; frequency offset; frequency-selective fading channel; minimum shift keying; offset compensation; sampled baseband signal; smoothed signal; symbol timing estimation; AWGN; Baseband; Clocks; Demodulation; Digital filters; Frequency estimation; Frequency shift keying; Frequency synchronization; Frequency-selective fading channels; Phase estimation;
Journal_Title :
Vehicular Technology, IEEE Transactions on
