Adaptive frequency-domain equalization and diversity combining for broadband wireless communications

Author

Clark, Martin V.

Author_Institution

Res., AT&T Labs., Red Bank, NJ, USA

Volume

1

fYear

1998

fDate

18-21 May 1998

Firstpage

409

Abstract

We introduce a new kind of adaptive equalizer that operates in the spatial-frequency domain, and uses either least mean square (LMS) or recursive least squares (RLS) adaptive processing. We simulate the equalizer´s performance in an 8 Mb/s QPSK (quaternary phase shift keying) link over a frequency-selective, Rayleigh fading multipath channel with ~3 μs RMS delay spread, corresponding to 60 symbols of dispersion. Our results show rapid convergence and tracking for a range of mobile speeds (up to ~100 mph). Moreover, a 2-branch RLS equalizer requires only ~50 complex operations per detected bit, which, at 8 Mb/s, is close to achievable with state-of-the-art digital signal processing technology

Keywords

Rayleigh channels; adaptive equalisers; adaptive signal processing; broadband networks; convergence of numerical methods; delays; diversity reception; fading; frequency-domain analysis; least mean squares methods; multipath channels; quadrature phase shift keying; radio networks; tracking; 2-branch RLS equalizer; 8 Mbit/s; LMS; QPSK; RMS delay spread; Rayleigh fading multipath channel; adaptive equalizer; adaptive frequency-domain equalization; adaptive processing; broadband wireless communications; convergence; digital signal processing technology; diversity combining; equalizer performance simulation; frequency-selective channel; least mean square; mobile speeds; quaternary phase shift keying; recursive least squares; spatial-frequency domain; tracking; Adaptive equalizers; Diversity reception; Frequency shift keying; Least squares approximation; Least squares methods; Multipath channels; Phase shift keying; Quadrature phase shift keying; Rayleigh channels; Resonance light scattering;

fLanguage

English

Publisher

ieee

Conference_Titel

Vehicular Technology Conference, 1998. VTC 98. 48th IEEE

Conference_Location

Ottawa, Ont.

ISSN

1090-3038

Print_ISBN

0-7803-4320-4

Type

conf

DOI

10.1109/VETEC.1998.686606

Filename

686606