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.
We propose a new framework for MIMO decoding based on a recently developed technique for reliably conveying linear equations over wireless channels. Each transmit antenna sends an independent data stream using the same linear code. As a result, any integer combination of the codewords is itself a codeword. Each receive antenna observes a random complex-valued combination of the codewords according...
The performance of multihop links is studied in this contribution by both analysis and simulations, when communicating over Generalized-K (KG) fading channels. The performance metrics considered include symbol error rate (SER), outage probability, level crossing rate (LCR) and average outage duration (AOD). First, the expressions for both the SER and outage probability are derived by approximating...
This paper addresses the power allocation and relay positioning problems in Amplify-and-forward cooperative networks over Weibull fading channels. We study adaptive power allocation (PA) with fixed relay location, optimal relay location with fixed power allocation, and joint optimization of the PA and relay location under total transmit power constraint, in order to minimize the outage probability...
In this paper, we propose an new admission control scheme jointly taking into account call-level QoS based on the dropping probability of handoff call and packet-level QoS based on the outage probability over threshold in IEEE 802.16e where user mobility is allowed and adaptive modulation and coding (AMC) is employed. The proposed admission control scheme is characterized by both a threshold for handoff...
In this paper we analyze the outage probability of a cooperative multihop parallel relay network in Nakagami-m fading channels. The general closed form expression of the outage probability is derived both for integer and arbitrary Nakagami parameter m. We present numerical results on the performance of the network. It shows a careful configuration of the network size and power sharing between nodes...
The performance of transmit antenna selection (TAS) in a two-hop amplify-and-forward (AF) MIMO relaying network over Rayleigh-fading channels is analyzed. Assuming that the source, destination are equipped with NS and ND antennas, respectively, and communicate with each other with the help of an NR-antenna relay, we derive closed-form cumulative distribution function (CDF) of received signal-to-noise...
In this paper, we investigate the outage performance of decode-and-forward (DF) based opportunistic cooperative communications with channel estimation errors at the receivers under Rayleigh fading channels, in which the effect of the direct link has been explicitly evaluated. To be specific, the exact expression of outage probability has been derived for arbitrary values of signal-to-noise ratio (SNR)...
The exact expressions for symbol error probability and outage probability of randomized distributed space-time codes (RDSTC) under Rayleigh fading are derived. The diversity gain derived in the literature uses the Chernoff bound which may not be achievable in general. Utilizing the exact expression, the achievable diversity gain of RDSTCs is validated. The analytical expressions are verified by Monte-Carlo...
Orthogonal frequency division multiplexing (OFDM) systems have enjoyed widespread adoption in high data rate wired and wireless networks, due to their ability to efficiently cope with slowly varying dispersive channels. This paper considers the information theoretic secrecy rates that are achievable by an OFDM transmitter/receiver pair in the presence of an eavesdropper that might either use an OFDM...
In this paper indoor wireless Infrared (IR) technology for healthcare monitoring is studied. Monitoring provides a continuous and reliable vital sign measurement to secure patient staying in the hospital. Considering that patient moving is inevitable, we focus on a mobile IR channel based on diffuse propagation. A model of mobile channel is developed through the study of statistical distributions...
We study a cognitive channel reuse approach for autonomous femtocell deployment in an OFDMA-based cellular network. The objective is to manage the uplink interference from macrocell users to femtocell access points. Macrocell users are normally far away from the base station and may cause strong uplink interference to the close-by femtocells. By cognitive interference recognition, a femtocell access...
In the planning of cellular networks, link budget calculation is the first step to get the maximum allowable cell radius that guarantees a target signal to interference plus noise ratio (SINR) with a certain level of outage probability at the cell border. The interference margin as one of key inputs for link budget is used to compensate for co-channel interference. In this paper, a mathematical analysis...
We theoretically study the performance of various fractionally-spaced, electronic PMD equalizers in coherent optical PDM QPSK systems using the multicanonical Monte Carlo method. We calculate the required number of equalizer taps for a specific outage probability and different system margins.
We analyze PMD impairments in 112-Gb/s PDM-QPSK coherent systems and quantify outage probabilities. We show that 1st-order PMD under-estimates PMD impairments, but modeling 2nd-order PMD as polarization-dependent chromatic dispersion significantly over-estimates PMD penalties.
Cooperative diversity is an attractive way to combat fading in wireless networks,. Conventionally, the outage probability, which measures robustness of the transmission to fading in cooperative communication, is deduced on the condition that the signal-to-noise ratio (SNR) is very high. However, the result is only an approximation. In this paper, proposed a new way to deduce the accurate outage probability...
We consider a Decoded-and-Forward (DF) cooperative relaying network without a direct link. We investigate the outage probability (OP) of cooperation systems with either a DF scheme or a Selective DF (S-DF) scheme when relay channels experience statistically different Rayleigh fading. In the case of the DF system, an upper and lower bound of the OP are established to show the asymptotic performance...
In recent years, multi-cell downlink (DL) collaborative multi-input multi-output (MIMO) transmission has drawn a lot of attentions due to its potential benefits in system throughput. However, the requirements on training and feedback may hamper its practical applications. In this paper, we consider a single-user collaborative random beamforming (Co-RBF) scheme to ease the training and feedback burden...
In this paper, we propose an accurate method for evaluating the performance of Ultra-Wideband (UWB) coherent receivers over the IEEE 802.15.3a channel model. Depending on the severeness of fading, the method consists of approximating the distribution of the captured channel energy by either a Coxian, gamma-mixture or lognormal distribution based on a least square fitting criterion. The proposed approximations...
Power control plays significant role in the cognitive network system where secondary users (SUs) co-exist with primary users (PUs), but the interference due to SUs may affect the performance of PUs. The approach of considering the outage probability of PU as quality of service (QoS) constraint, while using the maximization function of secondary user throughput is used in this paper. A generalized...
Incremental selection amplify-and-forward relaying (ISAF) has the best performance of outage probability among relaying strategies and has been identified as the best protocol. This paper proposes to jointly optimize power allocation (PA) and best-relay position based on cooperative diversity for ISAF in order to minimize outage probability. The closed-form solution to the adaptive allocation algorithm...
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.