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Proceedings ArticleDOI

Performance study of BFAM 2D-RLS channel estimator for AOFDM based two-way relay

01 Oct 2014-pp 48-53
TL;DR: An adaptive channel estimation scheme for two-way relay with node capability and the effect of channel estimation error on performance of Adaptive OFDM (AOFDM) is analyzed for pedestrian A (pedA) channel.
Abstract: In this paper we introduce an adaptive channel estimation scheme for two-way relay with node capability. The adaptive filter used is called Block Fast Array Multichannel 2D-Recursive Least Square (BFAM 2D-RLS). The modulation used is Orthogonal Frequency Division Multiplexing (OFDM) and channel estimation is done in the frequency domain. The proposed channel estimator considers correlation of channel frequency response in both time and frequency domain. The computational complexity is calculated and convergence performance of the adaptive channel estimator is studied. This paper also introduces an AOFDM scheme for two-way relay systems. The effect of channel estimation error on performance of Adaptive OFDM (AOFDM) is analyzed for pedestrian A (pedA) channel. All computer simulations are performed using MATLAB ®.
Citations
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Proceedings ArticleDOI
01 Nov 2015
TL;DR: An adaptive channel estimation scheme for Amplify and Forward (AF) two-way relay systems with frequency selective and fast varying channels is proposed and the performance of BFAM 2D-RLS filter in estimating fast varying Vehicular-A (Veh-A) channel is analysed.
Abstract: In this paper we propose an adaptive channel estimation scheme for Amplify and Forward (AF) two-way relay systems with frequency selective and fast varying channels. The modulation used is Orthogonal Frequency Division Multiplexing (OFDM). This adaptive filter is called Block Fast Array Multichannel 2D Recursive Least Square (BFAM 2D-RLS) filter. The complexity of this adaptive filter is comparable to that of Least Mean Square (LMS) algorithm while maintaining similar convergence rate as that of the standard Recursive Least Mean Square (RLS) algorithm. Computer simulation using Matlab is performed to analyse the performance of BFAM 2D-RLS filter in estimating fast varying Vehicular-A (Veh-A) channel. The results obtained is compared with slow varying channels.
References
More filters
Journal ArticleDOI
Jr. L.J. Cimini1
TL;DR: The analysis and simulation of a technique for combating the effects of multipath propagation and cochannel interference on a narrow-band digital mobile channel using the discrete Fourier transform to orthogonally frequency multiplex many narrow subchannels, each signaling at a very low rate, into one high-rate channel is discussed.
Abstract: This paper discusses the analysis and simulation of a technique for combating the effects of multipath propagation and cochannel interference on a narrow-band digital mobile channel. This system uses the discrete Fourier transform to orthogonally frequency multiplex many narrow subchannels, each signaling at a very low rate, into one high-rate channel. When this technique is used with pilot-based correction, the effects of flat Rayleigh fading can be reduced significantly. An improvement in signal-to-interference ratio of 6 dB can be obtained over the bursty Rayleigh channel. In addition, with each subchannel signaling at a low rate, this technique can provide added protection against delay spread. To enhance the behavior of the technique in a heavily frequency-selective environment, interpolated pilots are used. A frequency offset reference scheme is employed for the pilots to improve protection against cochannel interference.

2,627 citations

Book
01 Jan 2003
TL;DR: This paper presents a meta-anatomy of Adaptive Filters, a system of filters and algorithms that automates the very labor-intensive and therefore time-heavy and expensive process of designing and implementing these filters.
Abstract: Preface. Acknowledgments. Notation. Symbols. Optimal Estimation. Linear Estimation. Constrained Linear Estimation. Steepest-Descent Algorithms. Stochastic-Gradient Algorithms. Steady-State Performance of Adaptive Filters. Tracking Performance of Adaptive Filters. Finite Precision Effects. Transient Performance of Adaptive Filters. Block Adaptive Filters. The Least-Squares Criterion. Recursive Least-Squares. RLS Array Algorithms. Fast Fixed-Order Filters. Lattice Filters. Laguerre Adaptive Filters. Robust Adaptive Filters. Bibliography. Author Index. Subject Index. AC

1,987 citations

Journal ArticleDOI
B. Rankov1, Armin Wittneben1
TL;DR: Two new half-duplex relaying protocols are proposed that avoid the pre-log factor one-half in corresponding capacity expressions and it is shown that both protocols recover a significant portion of the half- duplex loss.
Abstract: We study two-hop communication protocols where one or several relay terminals assist in the communication between two or more terminals. All terminals operate in half-duplex mode, hence the transmission of one information symbol from the source terminal to the destination terminal occupies two channel uses. This leads to a loss in spectral efficiency due to the pre-log factor one-half in corresponding capacity expressions. We propose two new half-duplex relaying protocols that avoid the pre-log factor one-half. Firstly, we consider a relaying protocol where a bidirectional connection between two terminals is established via one amplify-and-forward (AF) or decode-and-forward (DF) relay (two-way relaying). We also extend this protocol to a multi-user scenario, where multiple terminals communicate with multiple partner terminals via several orthogonalize-and-forward (OF) relay terminals, i.e., the relays orthogonalize the different two-way transmissions by a distributed zero-forcing algorithm. Secondly, we propose a relaying protocol where two relays, either AF or DF, alternately forward messages from a source terminal to a destination terminal (two-path relaying). It is shown that both protocols recover a significant portion of the half-duplex loss

1,728 citations

Book
05 Apr 2010
TL;DR: In this article, the authors discuss each block of wireless link in detail including coding, modulation and the advanced topics such as multiplexing, mobile communication, software radio, OFDM and MIMO.
Abstract: Beginning with an overview of current scenario in the study of wireless communication systems and the presentation of fundamental concepts, the book gradually discusses each block of wireless link in detail including coding, modulation and the advanced topics such as multiplexing, mobile communication, software radio, OFDM and MIMO. All the chapters start with the simpler topics and gradually build up the advanced concepts through detailed explanations and illustrations. The chapters are extremely student friendly with rich pedagogy including case studies, solved examples, review questions, numerical problems and multiple choice questions to help students revise the concepts learnt through visualization and practice.

1,218 citations

Journal ArticleDOI
I. Kalet1
TL;DR: The maximum bit rate of multitone QAM (quadrature amplitude modulation) over a general linear channel is found and it is shown that the optimum power division for multitone signals is similar to the water-pouring solution of information theory.
Abstract: The maximum bit rate of multitone QAM (quadrature amplitude modulation) over a general linear channel is found. First, the overall bit rate for an AWGN channel with a two-level transfer function is maximized, using a multitone QAM system. The power distribution between the tones and the number of bits/symbol per tone is optimized for a given symbol error rate. Extending these results to the general channel, it is shown that the optimum power division for multitone signals is similar to the water-pouring solution of information theory. Furthermore, multitone QAM performance is about 9 dB worse than the channel capacity, independent of the channel characteristics. The multitone results throughout are compared to those of an equivalent single-tone linearly equalized system. The comparison shows that the multitone system is useful for some channels, e.g. those with deep nulls in the transfer function. The maximum bit error rate over a twisted-pair channel which is performance dominated by near-end crosstalk (NEXT) is also found. >

581 citations


"Performance study of BFAM 2D-RLS ch..." refers methods in this paper

  • ...The data rate and Bit Error Rate (BER) performance of the two-way relay system can be improved with the use of AOFDM [9]....

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