Using other than a wired connection to transfer signals or power. Includes optical and (ultra)sound, but most often refers to RF (radio-frequent). Distances can be as low as centimeters (e.g. RFID), there's no upper limit.

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6 views

Wireless sensor network using evolutionary game theory

I am new in matlab and i dont have idea about how simulate in matlab the following text a part of Dynamics stability in wireless sensor networks active defense model paper I need help to implement ...
0
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0answers
8 views

How do Coherence Time and Coherence Bandwidth influence the decision on the diversity scheme?

I came across a statement in a lecture slide which states: Coherence Bandwidth and Coherence Time govern our decisions about the diversity scheme that we would choose The lecture is in the field ...
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1answer
50 views

Controlling various Arduinos with Android

I have an upcoming project which requires me to use about 8 different Arduinos, probably more. They all perform a light show which turns off and on various LEDs at different timings to simulate a ...
0
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1answer
64 views

Antenna Diversity: two Yagi antennas to the Rx and Rx/Tx u.fl-male points on the wifi-NIC?

I looked at the BCM4312 file - available as as doc or a pdf - and it says: BCM4312 has 2 radio chains, one is a dedicated Rx chain, the other is shared by TX and > RX chain using an RF switch ...
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1answer
22 views

Remote Wireless 4CH Switch On/Off - Data PIN Network Cable

Planning Stage I'm in the planning stages of making a wireless on/off switch that will basically cut off pin 6 on a network cable. I know little about electronics and I've attempted to learn as much ...
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0answers
50 views

Why is it that using RTS/CTS in 802.11 improves its throughput?

There is a famous paper which has shown that using the RTS/CTS scheme for medium access improves the throughput of a 802.11 system compared to a classical medium access scheme. The paper: ...
2
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2answers
46 views

What makes DSSS a more robust transmission technique compared to FHSS?

In many textbooks it is stated that DSSS is more robust than FHSS. Especially in terms of interference and delay spread? What is the exact reason. Lets say we multiply a given bit 1 with a larger bit ...
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3answers
103 views

Is it possible to measure the distance of a WiFi access point from the receiver?

I have signal strength in dBm and frequency in MHz is is possible to find the distance?? Any idea about how to do it?
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1answer
56 views

Plain English explanation of the Space-time Code Block by Alamouti

I checked about the Space-time code block online, but all of the explanations are either short or too simple, or too mathematical and complex Could anyone here provide an explanation of what ...
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1answer
67 views

How to transmit CAN signals wirelessly without line of sight (LOS)

I have a scenario where I have an OBD-II interface transmitting data via CAN across six wires to a display. I will have power on either side of the wires, but I cannot assume that the wires will have ...
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2answers
35 views

How are the Intersymbol Interference and Symbol Time (duration) related to each other?

In a lecture slide I noticed that OFDM(Orthogonal frequency-division multiplexing) mitigates the problem of Intersymbol Intereference over wireless systems because the symbol time is increased, in ...
2
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1answer
35 views

Upload XBee firmware without a PC and XCTU

So, as the title suggests, I would like to know if there is a way of uploading a firmware to a XBee module, throug the serial without a PC. What I mean is, I have a microcontroller, I would have the ...
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3answers
33 views

Using Bluetooth 4.0/LE verses RF

I am asking this question in hopes to get a solid answer from anyone who has direct experience dealing with the most recent RF as well as Bluetooth 4.0/LE developments. What I am essentially trying ...
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2answers
29 views

the response of wireless channel to an input

I am reading the wireless of David Tse. In the 2nd chapter of this book there is a discussion about the response of the channel due to an input. It has said that since the channel is linear its output ...
2
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2answers
56 views

What phenomena does “Coherence Bandwidth”?

Could anyone please provide a simple explanation of what Coherence Bandwidth means, and how is that related to Delay Spread. I read some articles but they don't help me to form the relation between ...
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2answers
70 views

Explain Rayleigh Fading in plain English

For a couple of days I am trying to understand the Rayleigh Fading model, but I am failing to. I look at various articles and tutorials online, everything goes fine up to a points, but then a lot of ...
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2answers
74 views

Why one transistor switches on first than other

In the circuit diagram given below we have two transistors. And in the article it is given that one transistor will turn on first. Why this transistor turns on first
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1answer
71 views

Could anyone explain the two-ray ground-reflection model in plain English

I am studying about wireless communications and I need to understand the two-ray ground-reflection model for one of my assignments. However, I fail to understand it. Could anyone provide a ...
0
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1answer
80 views

Protecting a wireless router from voltage fluctuation

Background: I have a wireless router ASUS DSL_N12U. Input voltage and current is 12V , 1.5A respectively. I also have an Inverter (works on three modes: Solar, Battery, Mains) at my home. Problem: ...
0
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1answer
29 views

Coordinator + Repeater Xbee + End device configuration

I am trying to work on a Xbee based solution for transferring data from with in a specified area.I am using Xbee865LP for the same project. Now what i want to implement is Make one device act as ...
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0answers
41 views

Working of a field focusing element

I saw a setup of wireless power transfer and it used something called "magnetic field focusing element". Its placed in between the transmitter and receiver coil to increase the flow of flux into ...
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2answers
81 views

Why is IR Transceiver transmitting/receiving rubbish?

I am trying to interface two microcontrollers wirelessly using IR transceivers. The microcontroller I'm using is ATMega164PA running on a 3.3V supply at 8MHz and the transceiver is TFDU4101-TR3. I am ...
2
votes
1answer
42 views

Wireless telecom system (cellular with Erlang and spectral efficiency)

We have a spectrum of 20MHz that we will use on a wireless cellular system, which requires 50kHz per channel. The system is using cluster size K = 4 and the radius of every cell is R = 1 km. a) ...
2
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3answers
90 views

Wireless EEG electrode design

Currently, all 'wireless' EEG systems acquire signals from electrodes which are wired to an amplifier, a filter, a digitizer and then finally a wireless module. I want to design a system that's ...
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1answer
65 views

How to make a simple Video Switch?

I thought making this would be simple, but I've found it a lot harder than I anticipated! What I mean is that I have one screen/monitor, and two video players (all video is through RGB component, RCA ...
2
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1answer
64 views

Why does frequency splitting happen when two resonant circuits are magnetically coupled in wireless power transfer?

When two circuits are tuned to a self resonant frequency and are then magnetically coupled, the resonance happens at multiple frequencies if they are near. How and why does this happen?
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1answer
121 views

What is the 'best' way of communicating with small microcontrollers/devices?

var best = "simple & cheap"; I have a server in my apartment that I have an XBEE hooked up to. I use it to communicate with another XBEE plugged into an Arduino. I am trying to hook up many ...
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5answers
132 views

Best choice for low-power, short-range wireless communication

I'm working on a project which relies on wireless communication, and I'm looking for the best alternative. These are the design requirements: Is easy to interface with Arduino Works over a small ...
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2answers
51 views

How does Signal-Noise-Ratio related to receiver power

If I have the instaneous Signal-Noise-Ratio (of the receiver), but no other information, and I am interested in the instaneous \$\mathbf{Power_{received}}\$, is there any relationship between these ...
0
votes
2answers
52 views

QAM's performace and SN

1) QAM's signal formula is $$s(t) = I(t)sin(2\pi f t) + Q(t)cos(2\pi f t)$$ The I axis and Q axis are orthogonal to each other, but its angle is 45 degrees, or 30 degrees. At how many degrees does ...
2
votes
1answer
76 views

What kind of solar panel is required to keep a mobile alive forever?

I want to build a webcam from an old mobile and I want it to be solar powered. The phone use a 3.7V lithium-ion battery of 1500mAh capacity. The phone last 24h hours on one charge. So if I'm right, ...
0
votes
2answers
78 views

Could some one explain me technically as to why the bandwidth is severly limited in underwater channel for communications?

I understand that, due to the harsh characteristics of the underwater channel, the effective bandwidth for communication underwater (using acoustics) is severely limited. But i would like to know the ...
1
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1answer
66 views

How to calculate the shannons channel capacity and the bandwidth, for a desired BER and EbNo value?

I understand that, for BFSK modulation scheme, to achieve BER of \$10^{-5}\$, the required Eb/No is 12 dB, and this is theoretical value of the required Eb/No predicted from the graph below: ...
2
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0answers
28 views

How to implement selective automatic repeat request (ARQ) frame retransmission concept in simulink after detecting frame errors using CRC-4?

I have modelled an acoustic modem in simulink, i have used the CRC-4 (STD-ITU) scheme to protect the data for transmission, On the receiver end, the CRC decoder detects the errors in the received ...
0
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1answer
77 views

Build simple wireless door (open/close) sensor with Arduino or Attiny84/87

I have a spare Arduino uno, a few Attiny84 and a few Attiny87. In my Raspberry PI I have installed a RFM12Pi and have a spare RFM12b to use with Arduino. Last piece I have in the drawer is a sonic ...
4
votes
5answers
270 views

Object detection using sensors and then reporting the location

I am trying to prototype a sensor + location reporting chip that will do the following: Sense if a object is present over the top of it (a vehicle to be specific) Reporting the location of the chip ...
6
votes
2answers
202 views

How does this quartz antenna work?

I picked up something called a quartz antenna at a surplus store for $2.75 so I could tear it apart. This is what I found: There were two small cardboard boxes filled with loose quartz crystals ...
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1answer
28 views

Adding a router (no key) to an encrypted Zigbee network

Backstory: I'm looking to extend the range of a proprietary wireless system. From looking at diagnostic data I think it uses a 2.4GHz ZigBee network, propably Mesh configuration. It might not be ...
3
votes
1answer
184 views

RC LED “Bathroom occupied” indicator

I want to build a little LED indicator for my bathroom door. The basic idea is that when a person sits or stands next to the toilet, a little transmitter signals it wirelessly to the LED diode which ...
0
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0answers
33 views

TI CC1101 Wireless Module Problem

I'm using CC1101 wireless module breakout module with msp430 launchpad. I have two kits I want to make communicate. I'm able to communicate with the TI library. But the modules behave strangely. ...
1
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0answers
59 views

How to transmit HDMI audio and video by wireless means [closed]

A friend and I are working on a project and we need to be able to transmit and receive wireless audio and video signals at a very fast rate. The most convenient method we can see right now is HDMI. I ...
1
vote
0answers
21 views

Video guidance system for 3pi robot to PC

I am currently working on a graduate project. It aims to build the guidance video system from 3pi robot. The video input would determine the types of action that the robot needs to executed. I'd like ...
1
vote
1answer
111 views

How efficient is wireless electricity compared to wired electricity?

I am looking for data showing practical data/information on the efficiency of wireless (induction) transfer of electricity vs. wired transfer. There is some information out there but the source makes ...
2
votes
0answers
81 views

RSSI-Distance calculation help

Using this question as a guide I've been trying to calculate some distances based on RSSI values that I see in our lab. I filled in all the variables with actual data or approximations where necessary ...
2
votes
0answers
38 views

Is it possible to replace a CC2500 with a CC2531?

I have a working Arduino->CC2500 configuration, and I'd like to know if it's possible to replace that with a CC2531 USB dongle. Does the CC2531 have the ability to form the correct packet structure ...
0
votes
1answer
71 views

Designing a simple energy-efficient communication protocol?

What is the required background knowledge in order to be able to understand and work on the design of a communication protocol which has to be robust, simple and capable of coping with short contact ...
1
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2answers
71 views

Wireless USB interface

I have been developing code for this open source flight controller, and the one thing that I would like to improve with my workflow is to be able to flash the firmware wirelessly. I am able to ...
0
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0answers
23 views

Which Communication technology to use? [duplicate]

I want to create a network of transreceivers which are able to send data to one base station these transreceivers should also have support unique ID the range should be around 5KM power no issue but ...
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1answer
52 views

Wireless communication between microcontrollers

I want to do wireless communication between ATmega32 and Arduino Leonardo. I used RF433 MHz transmitter and receiver as shown in figure. I used USART at baud rate 300 at transmitter and receiver, but ...
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2answers
91 views

Wireless Power trasfer

I've been working lately on a new project. The project is to power a simple LED with a transferred power. The first thing that came to my mind is "Transformers". So, I surfed the internet, I found ...