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, for single-source wireless ad hoc networks, we develop a joint re-encoding and successive interference cancellation (SIC) scheme to realize interference-immune multi-hop relaying. Interference immunity means that the transmission rate is not affected by the mutual interference among the relays. This leads to a greedy near-optimal algorithm that is similar to the Dijkstra's algorithm...
It has been a challenge to develop efficient algorithms for relay selection and relay power optimization in arbitrarily large multi-hop wireless networks. In this paper, considering Gaussian networks with half-duplex decode-and-forward relays, we develop a practical network-wide signal processing procedure with which the relay's data rate is not degraded by mutual interference. Multi-hop relaying...
This paper develops a computationally efficient method to evaluate the competitive performance of multiple spectrum access strategies when they coexist and compete with each other in a heterogeneous cognitive radio network (CRN).We use aMarkov Model Bank (MMB) to model the operations of the heterogeneous CRN. Various spectrum sensing errors, spectrum sensing strategies, and spectrum access strategies...
In this paper, we develop a Markov Model Bank (MMB) to analyze the heterogeneous cognitive radio networks (CRN) with a large number of dissimilar secondary users (SU) coexisting and competing for multiple dissimilar channels. The MMB consists of a separate Markov chain for each SU. The Markov chains are connected implicitly by a few state transitional probabilities that can be derived by analyzing...
In this paper, we propose an analysis framework for the performance of heterogeneous cognitive radio networks with multiple different secondary users (SU) coexisting and competing for spectrum access. In order to model the operation of different SUs in a feasible manner, we use a bank of Markov models, where each SU is modeled by a separate Markov model. The individual Markov models are connected...
In this paper, we propose a method to calculate the throughput of multiple uncooperative cognitive radio users. We use a bank of Markov models to derive the fraction of time that each user spends in successful channel access. The mutual interference among the users is modeled into the transitional probabilities of the Markov models, which makes it tractable to calculate multiple user throughput in...
Based on an information model that classifies intermediate nodes in multicast networks into network coding, routing and replicating nodes, multicast max-flow and minimum cost optimization frameworks are formulated to solve optimization problems in wireless networks with or without network coding. Two special properties of wireless transmissions are taken into consideration, i.e., multi-hop cooperation...
One of the major challenges to cognitive radios is the synchronization of distributed radios onto the same spectrum white spaces which vary in time and space. In this paper, we propose a frequency-hopping spread spectrum transmission scheme which works reliably without any a priori handshaking assumption. Each cognitive radio independently detects white spaces, and then selects one of them to transmit...
Cognitive radio is a desirable technique for secondary users to utilize the spectrum gray space. In order to avoid intolerable interference to primary users, the transmission power of cognitive radios must be carefully managed. In this paper, we analyze the sum transmission power of a group of randomly distributed but fully cooperated secondary transmitters in a network consisting of one primary transmitter...
One of the major concerns of cognitive radios when used for secondary spectrum access is the potential of interfering primary users, considering especially that cognitive radios may be misbehaved or under malicious attacks. In this paper, we present a method for a cognitive radio to secure its transmission power purely from its physical-layer received signals. Built into the transceiver hardware as...
In ultra-wide bandwidth (UWB) communication systems, dense multipath and severe multiuser interference (MUI) make the receiver high in hardware complexity and power consumption. It is desirable to shift the computation-demanding work to users with plentiful power and computational resources. We propose two prefiltering schemes which combat the MUI and multipath effects in the transmitter, so that...
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.