Learn More
The conventional minimum mean-square error (MMSE) multiuser receiver requires that each particular user transmits a sequence of training symbols known to the receiver and the receiver estimates the user signatures using this knowledge. However, in the presence of multiaccess interference (MAI) during the training period and/or in scenarios with short(More)
—We consider a multi-relay amplify-and-forward cooperative communication scheme in wireless sensor networks with uniformly distributed nodes. Fixing the average total transmission power from the network and preserving fairness among the selected relays by constraining them to transmit with equal average powers, we aim to improve the signal reception quality(More)
Null-steering transmit beamformers aim to maximize the received signal power in the direction of the intended receiver while substantially reducing the power impinging on the unintended receivers located in other directions. The existing null-steering beamformers may not be directly applied in wireless sensor networks (WSNs) as they do not conform with the(More)
A multihop relaying system is analyzed where data sent by a multi-antenna source is relayed by successive multi-antenna relays until it reaches a multi-antenna destination. Assuming correlated fading at each hop, each relay receives a faded version of the signal from the previous level, performs linear precoding and retransmits it to the next level. Using(More)
Due to the unsupervised nature of wireless sensor networks (WSNs), intensive communications are required among the selected nodes to reach a consensus and synchronize prior to entering a distributed beamforming (DBF) procedure. Therefore, a sensible approach to select the nodes should not only take into account the required beampattern, but also should aim(More)
A cooperative communication network is considered wherein <i>L</i> sources aim to transmit to their designated destinations through the use of a multiple-antenna relay. All sources transmit to the relay in a shared channel in the first transmission phase. Then, the relay linearly processes its received signal vector using <i>L</i> relaying matrices and(More)
— We consider a multipoint-to-multipoint cognitive network wherein the communications from L sources to their designated destinations are carried out through the use of K relays in a dual-hop amplify-and-forward cooperative scheme. Aiming to maximize the worst signal-to-interference-plus-noise ratio of the L destinations, we develop a technique that jointly(More)
As the nodes in wireless sensor networks (WSNs) are independent units, an intensive communication among them is required to generate a common signal and synchronize before entering a distributed beamforming (DBF) phase. Therefore, it is crucial to select the participating nodes in DBF such that not only the resulting beampattern meets the beamforming design(More)
We consider <i>L</i> far-field terminals with one source and <i>L</i>-1 interferences that transmit to a wireless sensor network (WSN) with <i>K</i> uniformly distributed relaying nodes. Each relaying node receives a signal mixture from the <i>L</i> transmitters in the first phase, multiplies it with a properly selected beamforming weight and retransmits(More)