Showing papers by "Devendra Jalihal published in 2009"
26 Apr 2009
TL;DR: This paper proposes to improve upon the classical ESPRIT algorithm by incorporating the iterative reduced rank Hankel approximation (RRHA) technique, and shows that the degree of improvement brought forth increases with the increased number of RRHA-iterations.
Abstract: The exact time-of-arrival (TOA) information of the multi-path signals is crucial for optimal channel estimation in vehicular OFDM systems. Super-resolution algorithms such as ESPRIT (Estimation of Signal Parameters via Rotational Invariance Technique) have been applied to retrieve this information from embedded pilots in the received OFDM symbols. These algorithms have high applicability for vehicular wireless environs characterized by high Doppler frequencies which leads to faster auto-correlation averaging. In this paper, we propose to improve upon the classical ESPRIT algorithm by incorporating the iterative reduced rank Hankel approximation (RRHA) technique. We show that this allows achieving of a lower MSE (mean square error) compared to the classical ESPRIT algorithm. Further, we portray that the degree of improvement brought forth increases with the increased number of RRHA-iterations.
26 citations
26 Apr 2009
TL;DR: This paper analyzes the diversity multiplexing tradeoff (DMT) framework for the rate-adaptive SIMO (single input multiple output) receive diversity schemes, namely SIMO-MRC (maximal-ratio combining),SIMO-SC (selection combining) and SIMO -EGC (equal gain combining), and obtain closed form expressions of the DMT at finite SNR.
Abstract: Multiple antennas are widely used in modern high speed wireless data communication systems. Though multiple antennas provide diversity as well as multiplexing gain, there is a fundamental tradeoff between the two under slow fading channel conditions, that any coding scheme can achieve. This is captured in the diversity multiplexing tradeoff (DMT) framework at asymptotically high signal to noise ratios (SNR). The framework has been further generalized for the non-asymptotic i.e finite SNR case. In this paper we analyze the DMT for the rate-adaptive SIMO (single input multiple output) receive diversity schemes, namely SIMO-MRC (maximal-ratio combining), SIMO-SC (selection combining) and SIMO-EGC (equal gain combining). We obtain closed form expressions of the DMT at finite SNR. These expressions enable comparison of performance of the above schemes at finite SNR. The results of this comparative study are presented here.
4 citations
01 Jan 2009
TL;DR: The DMT arrived by analysis using the non-asymptotic finite SNR framework is found to be consistent with the known interpretations arrived through the asymptotic high-SNR framework.
Abstract: The Diversity Multiplexing Tradeoff (DMT) (1) is a compact, yet elegant framework to capture the performance of wireless communication systems at asymptotically high signal to noise ratios (SNR). Recent application of DMT at finite SNR (2) makes the DMT a versatile framework. We have analyzed the DMT for the rate-adaptive SIMO maximal-ratio combining (SIMO-MRC) for asymptotic and non-asymptotic signal to noise ratios. This has resulted in arriving at closed form expression of the diversity gain. The DMT arrived by analysis using the non-asymptotic finite SNR framework is found to be consistent with the known interpretations arrived through the asymptotic high-SNR framework (1). The results of this analysis have been presented in this paper.