In this paper we provide an analytical model to compute the throughput and energy consumption of IEEE 802.11ah, new Sub-1 GHz WiFi standard. The assumes known collision error probabilities applies both basic RTS/CTS access mechanisms. Comparison with simulation results shows that is extremely accurate in predicting system consumption. We also investigate 802.11ah including restricted window (RAW) mechanism, compare it scheme. obtained show RAW mechanism can substantial improvements...

In this paper we study the feasibility of IEEE 802.11ah radio technology for internet things (IoT) and machine to (M2M) use cases. Devices in networks are foreseen communicate wirelessly. Therefore, it is foremost importance have a reliable, low-energy wireless available that may be used anywhere anytime without draining device battery could achieve satisfactory coverage data rate. Here link budget, achievable rate packet size design different channel scenarios. System simulation results...

IEEE 802.11ah task group is working on a new amendment of the 802.11 standard, suitable for high density WLAN networks in sub 1 GHz band. It expected to be prevalent standard many Internet Things (IoT) and Machine (M2M) applications where it will support long-range energy-efficient communication dense network environments. Therefore, significant changes legacy standards have been proposed improve performance contention scenarios, most important which Restricted Access Window (RAW) mechanism...

In this paper, a new technique is proposed for blind estimation of carrier frequency offset (CFO) in wireless orthogonal frequency-division multiplexing (OFDM) systems with constant-modulus constellations. The scheme based on the assumption that channel slowly changes time domain respect to OFDM symbol duration. As consequence, effect given subcarrier two consecutive symbols approximately same. Based assumption, cost function derived such power difference between all subcarriers minimized....

This paper presents an efficient technique for reducing the bit error rate (BER) of orthogonal frequency-division multiplexing (OFDM) signals transmitted over nonlinear solid-state power amplifiers (SSPAs). The proposed is based on predicting distortion that SSPA would generate due to characteristics such devices. Similar selective-mapping or partial-transmit-sequence (PTS) schemes, predicted used select a set phases minimize actual distortion. Simulation results confirmed signal-to-noise...

Internet of Things (IoT) and Machine-to-Machine (M2M) applications are typically characterized by moderate investment costs to the M2M devices infrastructure, in addition high reliability energy efficiency requirements. The new Sub-1 GHz WiFi standard, namely IEEE802.11ah, is being introduced address these requirements deploying its recently specified MAC PHY features mechanisms. In this paper, we present an extensive analysis office 802.11ah network performance means realistic system level...

This letter presents an efficient technique to reduce the impact of nonlinear power amplifiers on bit error rate (BER) orthogonal frequency division multiplexing (OFDM) systems. The proposed is based well-established Partial Transmit Sequence (PTS), a amplifier model, and simple single point cross correlator. Unlike conventional PTS, optimum phase sequence in system selected by maximizing correlation between input output model. Simulation results have confirmed that BER using almost...

In this paper, we present a performance comparison between IEEE 802.15.4 which specifies the physical and media access control layers for low-rate wireless personal area networks (LR-WPANs) like ZigBee, 802.11ah, new global WLAN standard using sub-1 GHz frequency band, in terms of throughput energy consumption. Both standards are targeting low power applications with relatively high number nodes as IoT M2M applications. The simulations results demonstrate better 802.11ah mainly congested...

In this work, an efficient interleaving process is proposed for orthogonal frequency division multiplexing (OFDM) systems over impulsive noise channels. Unlike the conventional OFDM where implemented before inverse discrete Fourier transform (IDFT), scheme based on performing post IDFT. The aim of to average effect burst a large number symbols, which can reduce its impact bit error rate (BER) significantly. For system and channel models considered in simulation results have confirmed that...

This paper presents an efficient blind symbol timing estimation scheme for orthogonal frequency-division multiplexing (OFDM) systems with constant modulus constellation. The proposed technique is designed to estimate offsets by minimizing the power difference between subcarriers similar indices over two consecutive OFDM symbols based on assumption that channel slowly changes time. estimator (PDE) totally because it requires no prior information about or transmitted data. Monte Carlo...

Implementation of an antenna array on a 5G mobile phone chassis is crucial in ensuring the radio link quality, especially at millimeter-waves. However, we generally lack ability to design antennas under practical operational conditions involving body effects user repeatable manner. We developed numerical and physical phantoms human for evaluation handset 28 GHz. While model retains realistic accurate shape, our phantom has much simpler hexagonal cross section represent body. Gains phased...

In this letter, an enhanced yet computationally efficient algorithm is proposed for suppressing ICI due to phase noise in OFDM receivers. The method particularly targeted improve the detection error rate performance when high-order constellation size and long cyclic prefix are used. approach optimizes interpolation of estimated excess between adjacent symbols re-compensates residual CPE after interpolation. enhancement verified system with 64-QAM subcarrier modulation 1/4 prefix, shown...

Enabling the Internet of Things, machine-type communications (MTC) is a next big thing in wireless innovation. In this work, we concentrate on attractive benefits offered by emerging IEEE 802.11ah technology to support large number MTC devices with extended communication ranges. We begin comprehensive overview novel features introduced latest specifications followed development powerful mathematical framework capturing essential properties massive deployment unsaturated traffic patterns....

This study presents an iterative carrier frequency offset estimator for orthogonal division multiplexing (OFDM) systems. The proposed is based on the efficient Viterbi-and-Viterbi (VAV) algorithm. blind and can be used with non-constant modulus subcarrier modulations such as quadrature amplitude modulation (QAM). performance of assessed theoretically via Monte Carlo simulations over various channel models compared to other well established techniques in addition Cramèr–Rao lower bound....

The standard Alamouti space-frequency block code (SFBC) suffers from performance degradation when used over highly frequency-selective channels because the channel frequency response is not necessarily flat block. In this paper, we present an enhanced space decoding scheme for multiple-input multiple-output (MIMO) orthogonal frequency-division multiplexing (OFDM) systems selective channels. uses variations in consecutive subcarriers to adapt decoder. Simulation results of DVB-T2 system...

A new method for compensating the effects of impulse noise in OFDM systems has been presented by Rinne, Henriksson and Hazmi (see Proc. 7th International Workshop, Hamburg. Germany, p.183-187, Sept. 2002). It is shown that AWGN case, can effectively cancel noise. However time-frequency selective channel further measures are needed. The purpose this paper to present an enhanced estimation scheme standard overcome its sensitivity time frequency estimates. uses free pilots estimate corrupted...

In this work, a new technique for mitigating the impulsive noise impact on orthogonal frequency division multiplexing (OFDM) system is proposed, and its performance compared with previously published (referred to as time-domain interleaving (TDI) technique). TDI technique, samples contaminated by are spread in timedomain over N OFDM symbols using an interleaver after inverse fast Fourier transform (IFFT) process. Accordingly, effect of burst will be averaged symbols, which reduces bit error...

Enabling the Internet of Things, machine-type communications (MTC) is a next big thing in wireless innovation. In this work, we concentrate on attractive benefits offered by emerging IEEE 802.11ah technology to support large number MTC devices with extended communication ranges. We begin comprehensive overview novel features introduced latest specifications followed development powerful mathematical framework capturing essential properties massive deployment unsaturated traffic patterns....

This work considers the effect of timing errors on carrier frequency offset (CFO) estimation for orthogonal division multiplexing (OFDM) systems. In general, most research conducted OFDM systems assume that a wide range can be tolerated due to use cyclic prefix (CP). Although such assumption might valid bit error rate (BER) analysis, it not case other processes as CFO estimation. this work, Monte Carlo simulations have been used evaluate performance several state-of-the-art estimators The...

DVB-H offers reliable high data rate reception for mobile handheld and battery-powered devices. A link layer with error correction is defined to work on top of the DVB-T physical layer. The standard suggests use Reed-Solomon coding combined cyclic redundancy check detection as forward correction. However, there exist more powerful methods decoding. In this paper, a detailed comparison five different decoding strategies presented which all are compatible current standard. Comparison based...

This work presents a new technique for blind and joint estimation of symbol timing carrier frequency offset in wireless orthogonal division multiplexing (OFDM) systems. The is achieved by sensing the interference introduced at fast Fourier transform (FFT) output when or offsets exist. synchronization parameters are selected such that minimized. proposed estimator highly efficient because it does not require any overhead channel state information. Simulation results show system effective...

In this work, an elegant interleaving process is used not only to mitigate the impact of bursty impulsive noise on performance orthogonal frequency division multiplexing (OFDM) systems but also break multipath fading channel errors. While, conventional OFDM implement in domain, system proposed here uses a block interleaver size N <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> samples time domain. As result, diversity has been exploited...

This paper presents a robust timing recovery scheme for orthogonal space-time block coding (OSTBC) multi-input multi-output (MIMO) frequency division multiplexing (OFDM) systems with constant modulus constellation. In the proposed system, symbol is achieved either by minimizing power difference between adjacent subcarriers in one STC or similar indices consecutive blocks. The technique totally blind because it does not require any prior information about channel state transmitted data....