Title :
Error floor of pulse amplitude modulation with adaptive sampling in time-dispersive fading channels
Author :
Molisch, Andreas F. ; Bölcskei, Helmut
Author_Institution :
INTHFT, Tech. Univ. Wien, Austria
Abstract :
We consider the error floor of coherently and differentially detected PAM (pulse amplitude modulation) in time-dispersive fading channels; PAM includes PSK (phase shift keying) and QAM as special cases. We introduce a new Zak (1968) transform based method for computing the error floor. This method can be applied to arbitrary modulation formats and a very general class of time-dispersive channels. We prove that unfiltered BPSK exhibits no error floor when the sampling phase is chosen adaptively and (for coherent detection) the basis pulse satisfies a symmetry condition. For filtered BPSK there is an error floor, which depends on the filter bandwidth. For higher-order modulations, there is always an error floor; it can be attributed to I-Q crosstalk
Keywords :
adaptive signal processing; cordless telephone systems; crosstalk; differential detection; dispersive channels; fading channels; phase shift keying; pulse amplitude modulation; quadrature amplitude modulation; signal sampling; transforms; I-Q crosstalk; PSK; QAM; Zak-transform based method; adaptive sampling; coherent detection; coherently detected PAM; cordless communications systems; differentially detected PAM; error floor; filter bandwidth; filtered BPSK; higher-order modulations; phase shift keying; pulse amplitude modulation; sampling phase; symmetry condition; time-dispersive fading channels; unfiltered BPSK; Amplitude modulation; Bandwidth; Binary phase shift keying; Fading; Filters; Phase detection; Phase shift keying; Pulse modulation; Quadrature amplitude modulation; Sampling methods;
Conference_Titel :
Personal, Indoor and Mobile Radio Communications, 1998. The Ninth IEEE International Symposium on
Conference_Location :
Boston, MA
Print_ISBN :
0-7803-4872-9
DOI :
10.1109/PIMRC.1998.734689
