Results 171 to 180 of about 668,337 (217)

Robust Cognitive Radio Cooperative Beamforming

IEEE Transactions on Wireless Communications, 2014
We consider a cognitive radio (CR) relay network consisting of a cognitive source, a cognitive destination and a num- ber of cognitive relay nodes that share spectrum with a primary transmitter and receiver. Due to poor channel conditions, the cog- nitive source is unable to communicate directly with the cognitive destination and hence employs the ...
Sudhir Singh, Paul D. Teal, Pawel A. Dmochowski, Alan J. Coulson   +3 more
openaire   +2 more sources

Cooperative Spatial Reuse with Transmit Beamforming

2007 IEEE 66th Vehicular Technology Conference, 2007
A cooperative scheme enabling spatial reuse, namely cooperative spatial reuse (CSR), is proposed as a cooperative extension of the current TDMA-based MAC in wireless networks. In the CSR, a cooperative group is formed by the links that are willing to do spatial reuse.
Lu, Chenguang, Fitzek, Frank, Eggers, Patrick Claus F.   +2 more
openaire   +1 more source

Cooperative beamforming in Cognitive Radio networks

2009 2nd IFIP Wireless Days (WD), 2009
In this paper, the problem of cooperative beamforming is investigated in a heterogeneous underlay cognitive network. A major difference exists between a conventional cooperative beamforming problem and cooperative beamforming in a CR (Cognitive Radio)network due to the interference constraints imposed by primary network.
Maryam Abolfath Beigi, Seyed Mohammad Razavizadeh   +1 more
openaire   +2 more sources

Cooperative location-based adaptive beamforming

2012 5th International Symposium on Communications, Control and Signal Processing, 2012
Location information is widely used for cooperative techniques in the relays. In this paper we extended our proposed location-based adaptive beamforming algorithm (LBA) with cooperative relay techniques (CLBA) which takes the profit from available positioning information, based on the cooperation and reduction of the convergence time of weights vector ...
Shahid Mumtaz, Du Yang, Joaquim Bastos, Jonathan Rodriguez 0001   +3 more
openaire   +1 more source

Cooperative Beamforming and Power Control

2007 Conference Record of the Forty-First Asilomar Conference on Signals, Systems and Computers, 2007
This work presents an energy efficient, low-overhead scheme for cooperative beamforming in ad hoc networks. Collaborating nodes retransmit local signals to faraway destinations, multiplying the received analog waveform by a complex weight chosen (in a distributed fashion) to maximize the received SNR.
Sharon M. Betz, H. Vincent Poor, Athina P. Petropulu   +2 more
openaire   +1 more source

Cooperative beamforming in cognitive radio systems without feedback of receiver beamforming vectors to transmitter

Wireless Networks, 2021
In this paper, we investigate the problem of transceiver beamforming and power allocation in the downlink of a multiple input multiple output Cognitive radio system. In this system, a base station (BS) services multiple primary users (PU) and multiple secondary users (SU).
Mohssen Abbasi Jannat-Abad, Seyyed Mohammad Javad Asgari Tabatabaee   +1 more
openaire   +2 more sources

Direction-of-departure estimation using cooperative beamforming

2010 7th International Symposium on Wireless Communication Systems, 2010
In this paper a novel approach is proposed for estimating the direction-of-departure (DOD) in a frequency-selective multipath channel, where both the transmitter (Tx) and receiver (Rx) employ an antenna array. In particular, the proposed approach exploits the cooperation between the Tx and Rx beamformers, such that the Tx beamformer rotates its ...
Zhijie Chen, Athanassios Manikas
openaire   +2 more sources

Cooperative Precoding and Beamforming in Co-Working WLANs

2008 IEEE International Conference on Communications, 2008
The interference among multiple access points (APs) that co-exist in the same location, limits the capacity of co-working wireless local area networks (WLANs). In this paper, we propose a practical cooperative transmission scheme to mitigate the interference in co-working WLANs.
Wibowo Hardjawana, Branka Vucetic, Yonghui Li 0001   +2 more
openaire   +2 more sources

Optimal cooperative relay beamforming for interference minimization

2015 IEEE International Conference on Communications (ICC), 2015
We consider a wireless cellular network with multiple amplify-and-forward (AF) relays in each cell, assisting the communication of multiple source-destination pairs with relay transmission beamforming. Our objective is to minimize the maximum interference power among all active receivers in a neighboring cell subject to per-relay power and minimum ...
Ali Ramezani-Kebrya, Min Dong 0001, Ben Liang 0001, Gary Boudreau, Ronald Casselman   +4 more
openaire   +2 more sources

Partitioned one-bit feedback for cooperative beamforming

2010 44th Annual Conference on Information Sciences and Systems (CISS), 2010
Recently, it has been shown that a cooperative beamforming scheme can achieve considerable gain using node cooperation. Due to the distributed nature of cooperating nodes, it is necessary to obtain phase synchronization such that the common message transmitted from the different cooperating nodes can be added coherently at the receiver.
Gubong Lim, Leonard J. Cimini Jr.
openaire   +1 more source