Analysis of equalization for DS-UWB systems

In this paper, we analyze equalization for direct sequence based ultra-wideband (DS-UWB) systems using RAKE combining at the receiver. To this end, we consider the effective discrete-time impulse response at the RAKE combiner output and study the distribution of the zeros of the corresponding transfer function. Thereby, we apply the IEEE 802.15.3a standard channel model. Our findings suggest that linear equalization (LE) is well suited for the lower data rate modes of DS-UWB systems, whereas decision-feedback equalization (DFE) is favorably applied for high-data rate modes. These conclusions are confirmed by simulation results. It is also shown that LE and DFE perform relatively close to the matched filter bound limit.

[1]  Xiaodai Dong,et al.  Rake-MMSE-equalizer performance for UWB , 2005, IEEE Communications Letters.

[2]  Fuyun Ling.  Matched filter-bound for time-discrete multipath Rayleigh fading channels , 1995, IEEE Trans. Commun..

[3]  Alexandra Duel-Hallen,et al.  Delayed decision-feedback sequence estimation , 1989, IEEE Trans. Commun..

[4]  Robert Schober,et al.  On the distribution of zeros of mobile channels with application to GSM/EDGE , 2001, IEEE J. Sel. Areas Commun..

[5]  Robert Schober,et al.  The zeros of random polynomials: further results and applications , 2002, IEEE Trans. Commun..

[6]  C.A. Belfiore,et al.  Decision feedback equalization , 1979, Proceedings of the IEEE.

[7]  Bartosz Mielczarek,et al.  Performance of coherent UWB Rake receivers with channel estimators , 2003, 2003 IEEE 58th Vehicular Technology Conference. VTC 2003-Fall (IEEE Cat. No.03CH37484).

[8]  Ryuji Kohno,et al.  Low-complexity rake reception and equalization for MBOK DS-UWB systems , 2004, IEEE Global Telecommunications Conference, 2004. GLOBECOM '04..

[9]  Moe Z. Win,et al.  Performance of low-complexity RAKE reception in a realistic UWB channel , 2002, 2002 IEEE International Conference on Communications. Conference Proceedings. ICC 2002 (Cat. No.02CH37333).

[10]  Inkyu Lee,et al.  The effect of decision delay in finite-length decision feedback equalization , 1996, IEEE Trans. Inf. Theory.

[11]  John G. Proakis,et al.  Digital Communications , 1983 .

[12]  J. Foerster,et al.  Channel modeling sub-committee report final , 2002 .

[13]  V. Srinivasa Somayazulu,et al.  RAKE performance for a pulse based UWB system in a realistic UWB indoor channel , 2003, IEEE International Conference on Communications, 2003. ICC '03..

[14]  Andreas F. Molisch,et al.  Channel models for ultrawideband personal area networks , 2003, IEEE Wireless Communications.