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 we propose a power control policy over an imperfect fading channel within a cognitive spectrum sharing area. In particular, our proposed scheme maximizes the secondary user effective capacity subject to the average interference power and the secondary user transmit power constraints. We also investigate the minimization of average interference power at the Primary Receiver (PR) under...
In this paper, we aim to solve the multiuser multi-input multi-output (MIMO) downlink beamforming problem where one multi-antenna base station broadcasts data to many users. Each user is assigned multiple data streams and has multiple antennas at its receiver. Efficient solutions to the joint transmit-receive beamforming and power allocation problem based on iterative methods are proposed. We adopt...
In this paper, the fading broadcast channel with confidential messages is studied in the presence of statistical quality of service (QoS) constraints in the form of limitations on the buffer length. We employ the effective capacity formulation to measure the throughput of the confidential and common messages. We assume that the channel side information (CSI) is available at both the transmitter and...
In this paper, wideband waveform design for relay cognitive network will be presented. There is one transmitter, several relay nodes and one or several receivers in cognitive network. Assume there is no direct communication link between the transmitter and the receiver. We would like to jointly design the transmitted waveform and the FIR filters at the relay nodes such that the received signal to...
Cognitive radios have been proposed as a solution to the spectrum underutilisation problem and have been proven to increase spectrum efficiency whilst providing opportunities for futuristic technologies. However, increased levels of interference are expected with the introduction of secondary spectrum access, therefore, proper interference management within the cognitive framework is imperative. The...
In this paper, cognitive transmission under quality of service (QoS) constraints is studied. In the cognitive radio channel model, it is assumed that both the secondary receiver and the secondary transmitter know the channel fading coefficients perfectly and optimize the power adaptation policy under given constraints, depending on the channel activity of the primary users, which is determined by...
This paper investigates simple user selection strategies in a multiuser downlink system with a single transmitter, multiple legitimate receivers, and a single eavesdropper, where all nodes are equipped with multiple antennas. No information regarding the eavesdropper is presumed at the transmitter, and we examine the MIMO downlink channel with either single or multiple data streams per receiver. The...
We consider a generalised multi-receiver radio network under a quality-of-service (QoS) constraint that involves generalised carrier-to-interference ratios. This model includes as special cases many well-known schemes, such as those discussed by Yates (JSAC, 13(7): 1341-1348, 1995). A simple feasibility condition for the QoS targets, and a power-vector that yields those targets are given in closed...
We introduce a model of a generalised multi-receiver radio network with quality-of-service (QoS) constraints. There are two key functions: (1) Ni is non-decreasing and homogeneous and gives i's QoS as function of its carrier-to-interference ratios at each of K receivers, (2) nu_ik is a semi-norm that gives the interference experienced by transmitter i at receiver k as function of the power vector...
The single antenna user nodes at the transmitters and at the receivers share their antennas to form a virtual multiple antenna system and to realize the cooperative diversity. It can enlarge the systempsilas capacity and enhance the service quality of the ad hoc network and improve the systempsilas performance. Applying the orthogonal property of the space-time coding, we transform the vector signal...
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.