All of these factors drive an increase in complexity for every aspect of the system. We see this both within individual systems and in the interactions between systems. At MathWorks, working with a large and diverse customer base provides insight into how much modeling improves the likelihood of success, especially as system complexity increases.
Because wireless system design spans multiple signal domains, the technical disciplines required for success on projects can vary significantly. This can be a challenge when subsystems are built separately and integrated at the later stages of a project.
When you can gain insights into the full signal chain at the early phases of your development—from the antenna and array design, to the RF components, to algorithms you implement for signal processing—you have the greatest flexibility to make the most intelligent design choices. That is, each subsystem in a multi-domain subsystem contributes to the overall signal processing effort. It can greatly improve the cost and schedule of a project when a small design change in one portion of a system eliminates the need for a more complex change somewhere else in the system.
Another commonly-used technique for underwater communication involves the use of light waves. A main advantage of VLC is that it can provide higher data rates than acoustic communication, but at the cost of useful transmission distance. Typical ranges for optical modems underwater are in the single meters, and up to tens of meters, if high transmission power is used. This may be partly due to the scattering of light underwater during VLC, as well as the brightness of ambient light, which can be orders of magnitude more intense than the transmitter's signal.
Accordingly, to achieve long range VLC, the cost may be quite high. Not only are tens of Watts of additional transmission power needed, but also, the cost of a providing a receiving photodiode with high sensitivity can increase cost up to three orders of magnitude.
Furthermore, line of sight between the signal transmitter and receiver is required for communication, as well as high visibility in the water to reduce scattering and increase range. While acoustics is a preferred modality, since it offers ranges greater than a few meters, optics is still used for wireless sensor networks that can hop short distance to achieve an underwater network.
A challenge faced today for underwater wireless RF communications is sending data through RF signals from one point to another without packet loss. RF communication has many advantages, but it suffers significant attenuation when used in underwater communication; for example, wave amplitude decreases rapidly in a short distance.
In accordance with an aspect of an embodiment of the invention there is provided a method for providing a fountain display, the method comprising: In accordance with an aspect of an embodiment of the invention there is provided a fountain system. The fountain system comprises a plurality of communication nodes, each communication node being configured to operate when submerged in a liquid; and a plurality of fountain components for providing a plurality of fountain jets of liquid, each fountain component being linked to a communication node in the plurality of communication nodes and being operable to provide a fountain jet of liquid in the plurality of fountain jets of liquid.
For a better understanding of the various embodiments described herein, and to show more clearly how these various embodiments may be carried into effect, reference will be made, by way of example, to the accompanying drawings which show at least one example embodiment and the figures will now be briefly described.
Various devices, systems and methods will be described below to provide an example of at least one embodiment of claimed subject matter. No embodiment described below limits any claimed subject matter and any claimed subject matter may cover devices, systems and methods that differ from those described below. The claimed subject matter is not limited to devices, systems and methods having all of the features of any one device, system or method described below or to features common to multiple or all of the devices, systems and methods described below.
Any subject matter that is disclosed in a device, system, or method described below that is not claimed in this document may be the subject matter of another protective instrument, for example, a continuing patent application, and the applicants, inventors, or owners do not intend to abandon, disclaim, or dedicate to the public any such subject matter by its disclosure in this document.
Furthermore, it will be appreciated that for simplicity and clarity of illustration, where considered appropriate, reference numerals may be repeated among the figures to indicate corresponding or analogous elements. Further, analogous features may be indicated by reference numerals having a predetermined numerical variance, such as a multiple of For example, reference numeral may designate an analogous element to an element referred to with reference numeral Analogous elements may be similar in many respects, but different in some specific aspects, as may be indicated.
For brevity, where there are no relevant differences between analogous elements, the description of the operation of these elements may not be repeated. In addition, numerous specific details are set forth in order to provide a thorough understanding of the example embodiments described herein. However, it will be understood by those of ordinary skill in the art that the example embodiments described herein may be practiced without these specific details.
In other instances, well-known methods, procedures, and components have not been described in detail so as not to obscure the example embodiments described herein. Also, the description is not to be considered as limiting the scope of the example embodiments described herein. These terms of degree should be construed as including a deviation of the modified term if this deviation would not negate the meaning of the term it modifies. Furthermore, the recitation of any numerical ranges by endpoints herein includes all numbers and fractions subsumed within that range e.
The embodiments of the systems and methods described herein may be implemented in hardware or software, or a combination of both. Some embodiments may be implemented in computer programs executing on programmable computers, each computer including at least one processor, a data storage system including volatile memory or non-volatile memory or other data storage elements or a combination thereof , and at least one communication interface.
For example, and without limitation, the various programmable computers may be a server, network appliance, set-top box, embedded device, computer expansion module, personal computer, laptop, mobile telephone, smartphone or any other computing device capable of being configured to carry out the methods described herein.
Each software program may be implemented in a high level procedural or object oriented programming or scripting language, or both, to communicate with a computer system. However, alternatively the programs may be implemented in assembly or machine language, if desired.
Signals and Communication Technology. Free Preview. © EM Modeling of Antennas and RF Components for Wireless Communication Systems to EM analysis and designing of RF applications in modern communication systems. EM Modeling of Antennas and RF Components for Wireless Communication Systems. Authors; (view affiliations). Frank Gustrau Part of the Signals and Communication Technology book series (SCT). Download book PDF. Chapters Table of.
The language may be a compiled or interpreted language. Each such computer program may be stored on a non-transitory computer readable storage medium e. The storage medium so configured causes a computer to operate in a specific and predefined manner to perform the functions described herein. Wireless communication channel characteristics in air are well defined compared to wireless channel characteristics for underwater communications.
While a significant numbers of studies are commonly available for wireless communications in free space or in the atmosphere; few studies have been conducted to date for underwater RF wireless communications. Generally, a wireless channel may be characterized by four parameters, which vary depending on the type of the medium through which wireless signals in the channel are propagated. These four parameters are: A transmitted electromagnetic EM wave, when propagated through a medium, is attenuated within the medium of propagation in relation to a propagation constant.
The propagation constant is expressed as follows:. In dB units, where d is the depth of propagation inside water, a is expressed as follows:. When an electromagnetic wave passes through one medium to another medium some part of EM wave can be reflected back from the interface. This loss is referred to as interface loss. Interface loss is constant for a particular frequency and effectively independent of propagation distance.
Attenuation of RF signals in a medium increases both with increase in conductivity and increase in frequency. It can be calculated from the following formula:.
Water in its pure form is an insulator with high resistivity , but as found in its natural state e. Higher conductivity of water leads to greater attenuation of radio signals which pass through it.
Microwave Imaging Matteo Pastorino. Product details Format Paperback pages Dimensions The plurality of fountain control signals can be transmitted at a frequency in the range of MHz to 1. This indicates that using directive antenna to establish such communication link may be beneficial. This blog will focus on exploring those challenges and providing insights into solutions, including a collection of additional resources to help get you started. Conversely, at a depth of 2 inches it was possible to communicate, but RSSI was relatively low.
Conductivity a varies with both salinity and temperature See References , , and . Underwater communication is affected by permittivity and conductivity of the water. Freshwater has a typical conductivity of 0. Therefore, EM wave propagation can be more efficient in freshwater than in seawater.
Freshwater is characterized as a low loss medium. Signal loss is lessened where underwater communication is carried out at short distances See Reference .
It is evident that wavelength is shorter in water compared to its value in free space or air. In the case of freshwater, the attenuation coefficient is thus essentially frequency-independent unlike the case of seawater, see Equation 9 , and EM waves can literally propagate through freshwater body.
Referring now to FIGS. As shown particularly in FIG. Typically, n will be an integer considerably greater than 2, such as 10 or In the following, the plurality of nodes may be generally referred to as the nodes In various embodiments, the depth may be between 2 inches and 8 inches. In some embodiments, the depth may be greater than 8 inches or less than 2 inches. In some embodiments, the depth may be approximately any one of 2 inches, 4 inches, 6 inches or 8 inches. In some embodiments, the nodes may be located at different depths.
In various embodiments, the distance between nodes may be between 5 and 30 feet. In some embodiments, the distance may be greater than 30 feet or less than 5 feet. In some embodiments, the distance between nodes may approximately any one of 5 feet, 10 feet, 15 feet, 20 feet, 25 feet or 30 feet. Fluid storage vessel may be a vessel for containing a liquid, such as water. For example, fluid storage vessel may be a pool, a lake, a basin at the base of a fountain, or another type of vessel that contains water. In some embodiments, the vessel may contain water having minimal quantities of impurities, such as dissolved salts.
In various embodiments, enclosure may be a fluid-tight enclosure when submerged at predetermined depths within vessel Accordingly, when the enclosure comprising node is submerged at a predetermined depth within vessel , only insignificant quantities of fluid may leak into enclosure In various embodiments, enclosure has a larger internal volume than the total volume of the elements of node such that the total volume of the assembled elements of node can fit within the enclosure Enclosure may be filled with air in the portion of its internal volume not occupied by the elements of node Alternatively, other gases may fill the portion of enclosure not occupied by the hardware elements of node In various embodiments, transceiver comprises a transmitter for transmitting signals via antenna and a receiver for receiving signals via antenna In some embodiments, transceiver includes one or more oscillators and a digital signal processor DSP.
The digital signal processor may be used to send and receive signals to and from antenna In some embodiments, receiver and transmitter are connected to different antennas.
In some embodiments the transceiver is operable to emit signals at predetermined frequencies ranging from MHz to Mhz. Transceiver may also be operable to emit signals at predetermined bit rates. In some embodiments the transceiver is operable to emit signals at predetermined bit rates ranging from 1. In some embodiments, the transceiver is operable to emit signals at any or all of 1.
It will be understood that, transceiver may be operable to vary other output signal characteristics than those specifically indicated. For example, it may be desirable to increase output power in the event of a data loss. In alternate embodiments, the transceiver may have at least a predetermined signal output characteristic that cannot be varied. Various embodiments of antenna are contemplated. The selected antenna may have a predetermined power gain which may be expressed in DBi.
Antenna orientation may also be varied to provide a directional gain. The antenna may be a helical omnidirectional type antenna. The antenna may be a Larsen Antennas MHz antenna. As illustrated in FIG.
Referring now to FIG. In the illustrated embodiment, the antenna of each node projects outwardly from the enclosures In this embodiment, if the antenna does not include an inner air cavity, interface losses may be diminished as compared to embodiments where antenna is contained within enclosure As illustrated in FIGS. In some embodiments, various nodes may be connected to a single control module. Control module may be provided with software instructions to implement certain functionality. In some embodiments, control module may be a networked computing device, including a processor and memory, connected to a network for communications over the network.
Optionally, the nodes taken together may form a distributed computing system in that the nodes may communicate between each other to coordinate their actions, and to share processing requirement between the control modules of different nodes In some alternate embodiments—such as where control module is a networked computing device—at least part of a control module may be located outside of a node's enclosure The components may be external to the enclosure , or may be wholly or partially enclosed therein.
The components may be, for example, pumps, illumination components, nozzle position controls, or valves. In various embodiments, the components can be controlled by controller In some embodiments, the components may be hardware components of a fountain. These sensor readings relate to operational conditions of the components.
In embodiments where components comprise a pump, the pump may be connected to a flow rate sensor for generating flow rate sensor readings relating to measured output flow rate from the pump. The flow rate sensor may send the flow rate sensor readings to control module Upon receiving flow rate sensor readings, control module may process flow rate sensor readings in conjunction with stored application program instructions.
Control module may then send a pump control signal to controller , such that controller controls the pump to vary its output flow rate. In embodiments where components comprise an illumination component, the illumination component may be connected to an illumination setting sensor for generating illumination setting sensor readings relating to a measured illumination setting of the illumination component. The illumination setting may relate, for example, to a currently output colour, intensity, position or strobe pattern of light emanating from an illumination component.
The illumination setting sensor may send the illumination setting sensor readings to control module Upon receiving illumination setting sensor readings, control module may process illumination setting sensor readings in conjunction with stored application program instructions. Control module may then send an illumination control signal to controller , such that controller controls the illumination component to vary its illumination setting. In embodiments where components comprise a nozzle position control component, the nozzle position control component may be connected to a nozzle position sensor for generating nozzle position sensor readings relating to a measured nozzle position of a nozzle connected to nozzle control component.
The book offers a realistic view of the capabilities and limits of current 3-D field simulators and how to apply this knowledge efficiently to EM analysis and design of RF applications in modern communication systems. Product details Format Paperback pages Dimensions Bestsellers in Microwave Technology. RF Microelectronics Behzad Razavi. Four Pillars of Radio Astronomy: Mills, Christiansen, Wild, Bracewell H. Radio-Frequency Electronics Jon B.
Planar Microwave Engineering Thomas H.