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.
In this paper, a compressed sensing (CS) based sparse channel estimation method is proposed for Unique Word (UW) Prefixed SC-FDE employed in sparse wireless channels, sparse channel estimation is formulated as a typical CS problem, and UW generation schemes are discussed, in addition, DantzigD selector is used to recover sparse channel impulse response (CIR) from limited number of noisy observation...
Since radio links in wireless body area networks (WBANs) commonly experience highly time-varying attenuation due to topology instability, communication protocols with fixed transmission power cannot produce a very good performance in terms of energy consumption, interference range, and communication reliability. We explain that how channel behaviourcan be modelled using Markov Chain. Then, a power-adaptive...
This paper considers a wireless power transfer system with multiple antennas by using the multicarrier signal waveforms. A prior art optimizes the waveform with the channel state information at the transmitter (CSIT) to improve the energy harvesting efficiency of the receiver with the non-linear model. The impact of the imperfect CSIT on the energy harvesting capability is studied as a function of...
In this paper, we study a wireless cooperative secure transmission system with the help of a friendly cooperative jammer Chad to interfere a potential malicious eavesdropper Eve. For imperfect channel estimation, we continue to follow the optimal power allocation and the maximum secrecy rate design of the perfect channel. Considering channel estimation scenario in the actual communication environment,...
Ambient backscatter is a new technology that utilizes environmental wireless signals to enable battery-free devices to communicate with each other. In this paper, we investigate the problem of signal detection for the full duplex wireless system utilizing ambient backscatter. Since one of the key technologies of full duplex wireless system is self-interference cancellation, we first estimate the channel...
A key focus of wireless communications research is on solutions that catalyze broadband access everywhere at anytime. Relaying has been introduced as a solution to enable communication between users who suffer from poor channel conditions. Distributed relay networks are a special case where spatial diversity is obtained by using a relay consisting of many geographically dispersed nodes. Due to bandwidth...
In this paper, we study the issue of selecting the transmission power (energy per symbol) and power allocation between pilot and data symbols to maximize the energy efficiency (EE). We consider the system that has a slow-fading channel and employs a minimum mean square error (MMSE)-based channel estimation scheme for a pilot symbol-assisted modulation. We derive a closed-form expression for a lower...
Energy Harvesting is one of promising technique to solve the power limitation problem which becomes an important problem for next generation communication. Since the scheduling process of current communication systems causes heavy power consumption in serving a large number of devices, the grant-free communication becomes a viable option in machine-type communication with energy harvesting. In this...
There is a growing need for government agencies to prevent crimes and terror attacks by legitimately monitoring suspicious communication links. In this paper, two concepts named eavesdropping rate and eavesdropping outage probability are defined to evaluate the eavesdropping performance of legitimate monitor. Against the energy-ratio-based detection exploited by suspicious users, a hybrid eavesdropping...
Generalized frequency division multiplexing (GFDM) with the flexible structure is one of the promising candidates for the fifth generation wireless communication system. This paper focuses on training sequence design that is used in the estimation of in-phase(I) and quadrature(Q) imbalance parameters on GFDM receivers as well as frequency selective channel. Combining with the structure of low complexity...
Due to the broadcast nature of the wireless medium, private communications are easily eavesdropped. This has spurred extensive research into secret key establishment using physical layer characteristics of wireless channels. In all these schemes, the shared secret keys directly originate from the physical features of the real wireless channel, which is highly dependent on the communication environment...
A new adaptive algorithm is proposed for implementation of channel estimation for Orthogonal Frequency Division Multiplexing-Interleave Division Multiple Access (OFDM-IDMA)-based wireless communication systems. This is named the variable forgetting factor modified recursive least mean square (VFF-MRLS) algorithm. The modification imposed is based on the enforcement of a constraint on the a posteriori...
Transmission Power Control (TPC) protocols are poised for wide spread adoption in wireless sensor networks (wSNs) to address energy constraints. The link quality properties that need to be captured in order to identify the optimum transmission power (TP) have not been clearly defined and previous works have presented conflicting views on the matter. This has led to several current TPC protocols using...
The progressive increase of data rates in wireless communication systems has induced channel models with sampled impulse responses which are mostly sparse. This paper presents a unified derivation of adaptive filters exploiting sparsity in the complex domain, and compares the performance of classic and state-of-the-art adaptive algorithms for estimating sparse wireless channels as well as their tracking...
The paper proposes a fast multi-target detection technique based on simultaneous sensor data fusion for a binary wireless sensor network in a pre-deployed configuration. The synchronous binary sensors are circularly arranged in an area with the sink node on the central axis such that the line-of-sight communication dominates. All the binary sensors employed for detecting rapidly changing targets are...
We consider wireless information and power transfer in a multi-user massive multiple-input multiple-output (MU-Massive-MIMO) system, where several distributed antenna sets, also denoted as remote radio heads (RRHs), are deployed, while the users can simultaneously perform information detection and energy harvesting. Assuming a large number of antennas and autonomous power allocation for the information...
These days, we are witnessing that numerous machine-type devices are connected to the internet. Massive connectivity is one of the most important requirements for the next generation 5G networks. Since the complicated scheduling process of current 4G systems causes heavy load and large latency in supporting a large number of devices, the grant-free communication becomes viable option in massive machine...
This paper proposes optimum beamforming for a system consisting of a source, a full-duplex (FD) relay, an intended destination, and an eavesdropper. The source and destination are single-antenna nodes, whereas the FD relay is a multi-antenna node. Our objective is to find the optimum receive and transmit beamformers at the relay so that the secrecy rate is maximized. The joint optimization problem...
The Orthogonal Frequency Division Multiplexing (OFDM) is widely used in the wireless communication systems. The robustness in a wireless environment combined with the ease to perform the channel estimation (CE) are the reasons for the OFDM popularity. Commonly, the channel estimation(CE) is performed in frequency domain using pilot tones. It is known that the wireless communications may be affected...
High level of security is essential in wireless communications multimedia applications. The last few years there has been an increase in research interest in the potential of the radio channel's physical properties to provide communications security. These research efforts investigate fading, interference, and path diversity to develop security techniques for implementation in wireless systems. In...
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.