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176
Blind joint maximum likelihood channel estimation and data detection for single-input multiple-output systems
- in Proc. 6th IEE Int. Conf. 3G & Beyond
"... Abstract — Blind and semiblind adaptive schemes are proposed for joint maximum likelihood (ML) channel estimation and data detection for multiple-input multiple-output (MIMO) systems. The joint ML optimisation over channel and data is decomposed into an iterative two-level optimisation loop. An effi ..."
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Cited by 24 (14 self)
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Abstract — Blind and semiblind adaptive schemes are proposed for joint maximum likelihood (ML) channel estimation and data detection for multiple-input multiple-output (MIMO) systems. The joint ML optimisation over channel and data is decomposed into an iterative two-level optimisation loop. An efficient global optimisation search algorithm called the repeated weighted boosting search is employed at the upper level to identify the unknown MIMO channel model while an enhanced ML sphere detector called the optimised hierarchy reduced search algorithm aided ML detector is used at the lower level to perform the ML detection of the transmitted data. A simulation example is included to demonstrate the effectiveness of these two schemes. I.
MIMO Rate Adaptation in 802.11n Wireless Networks
"... This paper studies MIMO based rate adaptation (RA) in 802.11n wireless networks. Our case study shows that existing RA algorithms offer much lower throughput than even a fixed-rate scheme. The fundamental problem is that, all such algorithms are MIMO oblivious; they do not consider the characteristi ..."
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Cited by 13 (0 self)
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This paper studies MIMO based rate adaptation (RA) in 802.11n wireless networks. Our case study shows that existing RA algorithms offer much lower throughput than even a fixed-rate scheme. The fundamental problem is that, all such algorithms are MIMO oblivious; they do not consider the characteristics of diversity-oriented, single-stream mode and the spatial multiplexing driven, double-stream mode. We propose MiRA, a novel MIMO RA scheme that zigzags between intra- and inter-mode rate options. Our experiments show that MiRA consistently outperforms three representative
Energy-efficient uplink multi-user MIMO
- IEEE Trans. Wireless Commun
, 2013
"... Wireless Communications. This paper has been peer-reviewed but does not include the final publisher proof-corrections or proceedings pagination. © 2013 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, includin ..."
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Cited by 13 (0 self)
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Wireless Communications. This paper has been peer-reviewed but does not include the final publisher proof-corrections or proceedings pagination. © 2013 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works. Citation for the published paper:
STUDY OF PROPAGATION LOSS PREDICTION IN FOREST ENVIRONMENT
"... Abstract—A comprehensive review of radio wave attenuation in forest environments is presented in this paper. The classic analytical methods of propagation loss modeling and prediction are described first. This provides information on the physical processes that the radio waves undergo while propagat ..."
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Cited by 11 (3 self)
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Abstract—A comprehensive review of radio wave attenuation in forest environments is presented in this paper. The classic analytical methods of propagation loss modeling and prediction are described first. This provides information on the physical processes that the radio waves undergo while propagating through a forest. The focus of this paper is on the review and summary of the experimental work done in this area and the development of empirical propagation loss prediction models. The propagation loss variation due to external factors such as antenna height-gain, depolarization, humidity effect etc. are examined and discussed individually. In view of current research work done in this area, some possible future work is proposed to improve the performance of radio links in forest environment. 1.
Enhancing coverage and capacity for multiuser MIMO systems by utilizing scheduling
- IEEE Trans. on Wireless Commun
, 2006
"... Abstract — Recent studies have revealed that the remarkable capacity improvement resulting from an open-loop multipleinput-multiple-output (MIMO) spatial multiplexing system may come at the sacrifice of degrading link reliability. This tradeoff between antenna multiplexing gain against antenna diver ..."
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Cited by 10 (1 self)
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Abstract — Recent studies have revealed that the remarkable capacity improvement resulting from an open-loop multipleinput-multiple-output (MIMO) spatial multiplexing system may come at the sacrifice of degrading link reliability. This tradeoff between antenna multiplexing gain against antenna diversity gain may translate into smaller coverage areas. In this paper, we suggest using the multiuser diversity to replenish the diversity-deficient spatial multiplexing MIMO system. Specifically, we propose a fair scheduling scheme, called the strongestweakest-normalized-subchannel-first (SWNSF) scheduling, which requires only limited amount of feedback. Our analysis and results indicate that the SWNSF scheduling can significantly increase the coverage of the multiuser MIMO system while further improving the system capacity.
On the Implications of Layered Space-Time Multiuser Detection on the Design of MAC Protocols for Ad Hoc Networks “Personal, Indoor and Mobile Radio Communications, 2005. PIMRC 2005
- IEEE 16th International Symposium. IJCSNS International Journal of Computer Science and Network Security, VOL.8 No.4
"... Abstract-In this paper, we shed some light on the implications that using a recently proposed layered space-time multiuser detection technique has on MAC protocol design for ad hoc networks with multiple antennas. From this point of view, our work relates to both physical layer and network layer st ..."
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Cited by 9 (1 self)
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Abstract-In this paper, we shed some light on the implications that using a recently proposed layered space-time multiuser detection technique has on MAC protocol design for ad hoc networks with multiple antennas. From this point of view, our work relates to both physical layer and network layer studies. In fact, on the one hand physical layer aspects are important to characterize the behavior at the receiver, especially in terms of Bit and Packet Error Rates, but are rarely considered in conjunction with networking scenarios; on the other hand, networking aspects are typically studied using drastically simplified physical layer models that, while allowing easier networking analysis, are often too restrictive or unrealistic. Also, this disconnect between physical and networking layer studies may severely limit the possibilities for cross-layer optimization, which appears to be the right approach for efficient wireless network design. Our paper is then an effort to establish some connection between the "physical" and "network" approaches, highlighting some interesting capabilities that ad hoc networks with multiple antennas are endowed by the use of multiuser detection.
CSI-SF: Estimating Wireless Channel State Using CSI Sampling & Fusion
"... Abstract—One of the key features of high speed WLAN such as 802.11n is the use of MIMO (Multiple Input Multiple Output) antenna technology. The MIMO channel is described with fine granularity by Channel State Information (CSI) that can be utilized in various ways to maximize the network performance. ..."
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Cited by 8 (0 self)
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Abstract—One of the key features of high speed WLAN such as 802.11n is the use of MIMO (Multiple Input Multiple Output) antenna technology. The MIMO channel is described with fine granularity by Channel State Information (CSI) that can be utilized in various ways to maximize the network performance. Many complex parameters of a MIMO system require numerous samples to obtain CSI for all possible channel configurations. As a result, measuring the complete CSI space requires excessive sampling overhead and thus degrades the network performance. We propose CSI-SF (CSI with Sampling & Fusion), a method for estimating CSI using a small number of frame transmissions and extrapolating data to settings that have not been sampled. For instance, we predict CSI of multiple stream settings using CSI obtained only from single stream packets. We evaluate the effectiveness of CSI-SF on various network scenarios using our
Investigations of foliage effect on modern wireless communication systems: A review
- Progress In Electromagnetics Research
"... Abstract—In this paper, a large number of studies of the effect of the foliage on single or lines of trees on modern wireless communication systems are reviewed. The paper is focused on the experimental works mainly done for commercial applications such as cellular communication and high speed point ..."
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Cited by 6 (0 self)
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Abstract—In this paper, a large number of studies of the effect of the foliage on single or lines of trees on modern wireless communication systems are reviewed. The paper is focused on the experimental works mainly done for commercial applications such as cellular communication and high speed point-to-point fixed link at the microwave and millimeter wave frequencies. For this review study, the development of the foliage loss prediction methods and the factors influencing the tree-induced shadowing effect are highlighted. In view of current research work in this area, some possible future works are proposed to improve the performance of modern wireless communication systems with the effect of foliage. 1.
User Pairing for Multiuser SC-FDMA Transmission over Virtual MIMO ISI Channels
"... Abstract—This paper proposes different criteria for user pairing for a virtual multiple-input multiple-output (V-MIMO) singlecarrier frequency-division multiple access (SC-FDMA) transmission over intersymbol interference (ISI) channels. Two users, equipped with a single antenna each, transmit their ..."
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Cited by 6 (0 self)
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Abstract—This paper proposes different criteria for user pairing for a virtual multiple-input multiple-output (V-MIMO) singlecarrier frequency-division multiple access (SC-FDMA) transmission over intersymbol interference (ISI) channels. Two users, equipped with a single antenna each, transmit their data in the same time slot and frequency band. The receiver at the base station (BS) is assumed to have two antennas and separates both users with a multiuser equalizer. For this, linear minimum mean-squared error (MMSE) equalization and successive interference cancellation (SIC), respectively, are chosen. Various pairing criteria are proposed and compared by simulations for a transmission in the uplink of E-UTRA Long Term Evolution (LTE). The simulation results indicate that well-designed user pairing strategies yield significant gains compared to random user pairing. It is shown that the proposed novel bit error rate (BER) pairing achieves a significant performance gain compared to capacity pairing for a SIC receiver and higher order modulation. I.
Adaptive RF chain management for energy-efficient spatial-multiplexing MIMO transmission
- in Proc. ACM/IEEE Int. Symp. Low Power Electronics and Design San Fancisco
, 2009
"... We present the theoretical foundation, implementation, and experimental evaluation of a novel power-saving mechanism for wireless transmission from multiple-input multiple-output (MIMO) transceivers, called RF chain management. RF chain management seeks to minimize the energy per bit for MIMO transm ..."
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Cited by 6 (5 self)
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We present the theoretical foundation, implementation, and experimental evaluation of a novel power-saving mechanism for wireless transmission from multiple-input multiple-output (MIMO) transceivers, called RF chain management. RF chain management seeks to minimize the energy per bit for MIMO transmission, via adaptively choosing the optimal RF chain configuration, and satisfies the minimum data rate requirement at the same time. Our simulation shows that up to 45 % and averagely 23 % energy per bit reduction can be achieved. We have also built a prototype based on the WARP platform, and our experimental results have proved the feasibility of RF chain management in real systems and under realistic channels.
