The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
This paper presents a resource allocation (RA) strategy for bit interleaved coded UFMC (BIC-UFMC) communications to be applied in an Internet of Things scenario characterized by short packets. The proposed RA strategy selects the best transmission parameters (TPs), i.e. code rate, bit loading (BL), power allocation (PA) and number of multicarrier symbols, by maximizing the goodput (GP) metric, defined...
The performance of multicarrier systems can be considerably degraded because of inter-carrier interference (ICI) caused by a carrier frequency offset (CFO) between the transmitter and the receiver. A recently developed multicarrier modulation technique, referred to as uniform filtered multicarrier (UFMC), improves the robustness against CFO, thereby relaxing the synchronization requirements, consequently...
This paper outlines an efficient resource allocation (RA) algorithm for packet-oriented Universal Filtered Multi-Carrier (UFMC) communications with bit interleaved coded (BIC) modulation. Assuming perfect synchronization and perfect knowledge of the channel, the proposed RA strategy optimizes the coding rate, bit loading and power distribution within the subbands and the subcarriers of the BIC-UFMC...
Among the user equipment (UE) assisted position applications in Long Term Evolution (LTE), the observed time-difference of arrival (OTDOA) method which uses measurements reported by the UE physical layer provides the highest precision. The UE measurement task is based on dedicated positioning pilot signals and translates to a time synchronization problem, which is the focus of this paper work. Our...
Non classical signals, signals not made of rectangular shaped pulses, are being analyzed as possible candidates for the next generation of GNSS signals. One such a signal is the filtered multi-tone (FMT) which is a multi-carrier signal (MC) having a MC-DS-CDMA structure: each subcarrier transports a classical GNSS signal but without using rectangular shaped pulses. Some studies have been conducted...
Since J. Mitola's seminal work in the 90's, Software Defined Radios (SDRs) have been a hot topic in wireless communication research. Though many notable achievements were reported in the field, the scarcity of computational power on general purpose CPUs has always been a limiting factor. If conveniently applied within an SDR context, classical concepts known in computer science as space/time trade-offs...
It is known that parameter estimation is present in any type of navigation systems. Signal Time-Of-Arrival (TOA) estimation accuracy is fundamental to the functioning of Global Navigation Satellite Systems (GNSS). This work investigates the Ziv-Zakai bound (ZZB) as a theoretical performance limit in TOA estimation. This bound has no constraint in terms of applicability, but becomes not attractive...
This work tackles the issue of channel estimation in the context of non-binary-LDPC-coded OFDM systems over doubly-selective multipath channels. The properties of channel encoding are exploited to derive an iterative Wiener-filter-based estimation method using both time and frequency channel correlation. The proposed algorithm can use either soft information or hard decisions fed back by the decoder...
This paper studies the performance of coherent and noncoherent code alignment detectors in the uplink of a flat-fading CDMA wireless network. A distributed resource allocation scheme in which each pair transmitter-receiver can set its own transmit power and detection threshold is considered to maximize the probability of code detection per consumed energy at the transmitter under a constraint on the...
This paper proposes a game-theoretic approach to the problem of resource allocation for a CDMA wireless communication network, focusing on code synchronization. To capture the tradeoff between obtaining good synchronization performance and saving as much energy as possible, we propose a noncooperative game in which each pair transmitter-receiver in the network seeks to maximize the ratio of the probability...
This work considers the problem of channel estimation in the context of non-binary-LDPC-coded OFDM transmission over doubly-selective multipath channels. The potential of channel encoding is exploited to derive an iterative Wiener-filter-based estimation method using both time and frequency autocorrelation of the channel. The proposed algorithm can use either the soft information or the hard decisions...
This paper is concerned with the general issue of game-theoretic techniques applied to the problem of resource allocation in wireless communication networks. Specifically, its first part is devoted to a tutorial explanation of game theory in the context of CDMA wireless networking, whilst the second part focuses on the particular issue of allocating power resources to optimize the receiver performance...
Transferring large amounts of information to fast moving vehicles on the highway has always been difficult task for any employed wireless transmission system, due to channel's heavy double time / frequency selectivity. Still, the possibility to make such delivery both possible and cost-efficient remains highly interesting for applications including, but not limited to, traffic data delivery, broadcasting...
Preliminary results on the performance of near field focused planar microstrip arrays working at 1.8 GHz have been shown, with reference to an 8 times 8 array with linear and circular polarization. Contour plots for the field at 1.5 m from the antenna aperture have been provided. Experimental results will be shown at the conference. To reduce cost production, future prototypes will be made of four...
This paper shows how to tailor a game-theoretic approach to the issue of distributed resource allocation in a multiple-access wireless network with different quality of service constraints. According to the nature of the terminals (either fixed/vehicular or mobile/battery-powered, in one respect, and either licensed or unlicensed in another), each user pursues a different goal in the network. Game...
The Cramer-Rao bound (CRB) with its modifications is a well known lower bound on the variance of any unbiased estimator of an unknown parameter. Focusing on the estimation of the time-delay experienced by a digitally modulated signal, we first introduce an approximation of the modified Cramer-Rao bound (MCRB) as a function of the spectral properties of the modulated signal, irrespective of the specific...
Multicarrier (MC) signals, now well-known and widely adopted in the field of terrestrial wireless communications, are being adopted also in the field of satellite communications with the DVB-SH standard. The main motivation of MC signaling is its intrinsic ronbustness to multipath (frequency-selective) channels. On the other hand, multipath is known to be one of the dominant sources to the error budget...
Satellite-based telecom systems provide the best and quickest solution to reducing the digital divide in less-favored areas owing to their wide geographical coverage and the speed and ease of deployment of terminal equipment. However, satellite system must be efficient and cost effective, and capable of full inter-working with state-of-the-art terrestrial broadband networks. This paper presents a...
This paper deals with the computation of the Cramer-Rao lower bound (CRB) for direction of arrival (DOA) estimation of ultra wideband-orthogonal frequency division multiplexing (UWB-OFDM) signals detected by antenna arrays for millimetre-wave applications. The CRB on DOA estimation of UWB-OFDM sources is evaluated by extending the mathematical model of DOA estimation of narrow band signals to wideband...
A new technique to acquire pseudo-noise (PN) sequences has been recently proposed in [1] and [2]. It is based on the paradigm of iterative message passing (iMP) to be run on loopy graph. This technique approximates the maximum-likelihood (ML) estimator, providing a sub-optimal algorithm that searches all possible code phases in parallel, at low complexity and fast acquisition time. This work is addressed...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.