Review of Distributed Beamforming, Journal of Telecommunications and Information Technology, 2011, nr 1

As the capabilities of individual nodes in wireless sensor networks increase, so does the opportunity to perform more complicated tasks, such as cooperative distributed beam- forming to improve the range of communications and save precious battery power during the transmission. This work presents a review of the current literature focused on implementing distributed beamformers; covering the calculation of ideal beamforming weights, practical considerations such as carrier alignment, smart antennas based on distributed beamformers, and open research problems in the field of distributed beamforming

Random beamforming in heterogeneous networks

With the progression of geometric beamforming techniques, the time to expand beyond isotropic networks has arrived. By taking into account the gains and beam patterns of individual elements in a beamforming array, a heterogeneous network may perform the same beamforming goals as an isotropic network. The focus of this work is the concept of randomly distributed arrays of nodes that wish to perform beamforming to maximize their radiation pattern towards an intended receiver while minimizing their pattern towards a set of interferers utilizing their position information. The use of the nodes\u27 position information rather than the nodes\u27 channel state information (CSI), called geometric beamforming, allows for the nodes to calculate their weights using significantly less data, and therefore less overhead in the cooperation phase prior to beamforming. The drawback is the relative ease of distributed calculations with the CSI model, where less information needs to be shared overall. In addition, utilizing position information rather than harvested CSI data allows for additional capabilities such as non-cooperative null steering. This work introduces a new heterogeneous beamforming model which takes anisotropic antenna patterns into account. Several applications of the new model are introduced and treated to both theoretical and numerical analysis including distributed weight calculations and initial research into tiered beamforming—a technique made possible by the new heterogeneous model

NSC54353

As block coding and intelligent receiver combining in multi-antenna systems moves from the theoretical into the physical domain, it is necessary to apply robust analysis to the problems encountered with the development of real radio systems that are often overlooked during theoretical development of methods and processes. One such problem is the lack of synchronization between the transmitter and receiver sampling clocks. This text attempts to analyze the significance of poorly correcting for differences in the transmit and receive sample clocks by simulating the BER of an Alamouti space-time coded system under a variety of sample rates and clock offsets. The results can be used to estimate the impact on link quality by a given sampler’s estimation error using the empirical model given

NSC27930

As the demand for high wireless data rates in indoor environments grows, we must find new ways to increase the performance of wireless links in multi-path fading. One common way to do this is to add diversity in the form of spatial or temporal diversity through the application of space-time block codes (STBCs). Recently, a method for combining STBCs with polarization diversity has been presented that allows for modeling the changes in polarization with quaternion numbers, introducing space-time-polarization block codes (STPBCs). This presentation shows some results from an initial investigation into the quality of cross polarized channels as compared to spatially separated channels to determine the feasibility of using STPBCs to enhance wireless data rates. It also presents a comparison of ergodic capacity of cross polarized channels and spatially separated transmits with polarized receive channels to compare the usefulness of hybrid spatial/polarization diversity schemes

Augmenting Mental Health Support for Patients Accessing Different Degrees of Formal Psychiatric Care through a Supportive Text Messaging Program: Protocol for a Randomized Controlled Trial

Patients feel more vulnerable when accessing community mental health programs for the first time or after being discharged from psychiatric inpatient units. Long wait times for follow-up appointments, shortage of mental health professionals, lack of service integration, and scarcity of tailored support can weaken their connection to the health care system. As a result, patients can present low adherence, dissatisfaction with treatment, and recurrent hospitalizations. Finding solutions to avoid unnecessary high-cost services and providing tailored and cost-effective mental health interventions may reduce the health system burden and augment patient support. We propose implementing an add-on, supportive text messaging service (Text4Support), developed using cognitive–behavioural therapy (CBT) principles to augment mental health support for patients attending to or being discharged from psychiatric care in Nova Scotia, Canada. This randomized controlled trial aims to investigate the effectiveness of Text4Support in improving mental health outcomes and overall mental well-being compared with usual care. We also will examine the intervention’s impact on health services utilization and patient satisfaction. The results from this study will provide evidence on stepped and technology-based mental health care, which will contribute to generating new knowledge about mental health innovations in various clinical contexts, which is not only helpful for the local context but to other jurisdictions in Canada and abroad that are seeking to improve their health care