Collaborative beamforming is a powerful technique to increase communication energy efficiency and range in an energy-constrained network. To achieve high performance, collaborative beamforming requires accurate knowledge of channel state information (CSI) at the transmitters (collaborative nodes). In practice, however, such exact knowledge of CSI is not available. A robust transmitter design ba...

This paper considers a cooperative Orthogonal Frequency Division Multiplexing (OFDM)-based cognitive radio network, where the primary system leases a fraction of its subcarriers to the secondary system in exchange for the secondary users (SUs) acting as decode-and-forward relays. Our aim is to determine an fair resource allocation strategy among the primary users and SUs as so to maximize the n...

This paper focuses on the algorithm for effective allocation of radio resources in future wireless communication systems. Conventionally the radio resources that have been used to add capacity to wireless communication systems are radio bandwidth and transmitter power. These two resources are simply not growing or improving at rates that can support expected demands for wireless capacity. Keepi...

The cyclostationarity of the OFDM signal induced by the cyclic prefix can be employed in a manner of blind channel identification for adaptive subcarrier modulation level and/or power allocation in an adaptive OFDM system, according to channel conditions, promising the potential for a high-speed power line communications. For that object, the spectral correlation characterization of the OFDM si...

A novel cross-layer wireless resource allocation algorithm called DBMQT is proposed which distributes the resource based on dynamic buffer allocation mechanism for orthogonal frequency division multiplex access (OFDMA) system. The aim of allocation algorithm is to maximize system throughput while satisfying the QoS requirement for multi-user and multi-service. The algorithm consists of two step...

This paper considers resource allocation to achieve max-min fairness in a selection-based orthogonal frequency division multiplexing network wherein source nodes are assisted by fixed decode-and-forward relays. The joint problem of transmission strategy selection, relay assignment, and power allocation is a combinatorial problem with exponential complexity. To develop effective solutions to the...