Wiener LMS Based Multipath Channel Estimation in WCDMA and cdma2000

Real-time DSP and FPGA Implementation of Wiener LMS Based Multipath Channel Estimation in 3G CDMA Systems

“…We define the averaged autocorrelation sequence r ww [n] for the absolute time lag n, to be given by [31] …”

“…Based on dependence graph technique [11] different area-time efficient mappings were possible. Recently, a VLSI architectures targeted on FPGA are proposed in [24] for a multiuser channel estimation method using Wiener LMS (WLMS) [31]. However, many advanced techniques are computationally demanding and cannot be performed in real-time.…”

“…Thus, typical commercial systems, such as IS-95, use single-user sliding correlators and Rake receivers. In this paper, we redesign a recently developed multiuser channel estimation technique [31] based on a multiuser WLMS algorithm and develop a much more efficient technique using fast Fourier transform. It has been depicted in [24] that up to a maximum of 19 users can be processed simultaneously with respect to WCDMA real-time constraints (e,g, 256 code length).…”

“…In our paper, a multiuser-LMS-like structure along with smoothing and prediction filters to improve tracking quality is reviewed [31]. The choice for such an adaptation family stems from its low computational complexity and its regular structure, which is favorable for an efficient VLSI implementation where parallelism and advanced pipelining (e.g.…”

“…The paper is organized as follows: Section 2 reviews the multiuser WLMS multipath channel estimation technique in a DS-CDMA context [31]. In Section 3, a low complexity FFT based technique is derived.…”